Weather in Langkawi: What You Should Know Before You Go

Gambar Profil Penulis
cover image

Langkawi is a stunning archipelago off the northwest coast of Malaysia, renowned for its natural beauty, laid-back charm, and diverse attractions. Pristine beaches, lush rainforests, and scenic waterfalls coexist with luxury resorts and local villages, creating a destination that appeals to both nature lovers and leisure seekers. The island’s culinary scene is equally vibrant, offering everything from fresh seafood and traditional Malay fare to international cuisine. With a wide range of outdoor activities and shopping options, Langkawi is a favourite among tourists seeking relaxation and adventure.

If you’re planning a trip to Langkawi, it’s advisable to check the weather forecast in advance. This will help you plan your activities and travel routes based on the prevailing weather conditions. In this article, we will explore Langkawi’s typical weather patterns and share useful tips to help you make the most of your visit.

Seasons in Langkawi

Langkawi experiences a tropical climate with warm temperatures and high humidity throughout the year. The island does not have four distinct seasons but instead is influenced by two main weather patterns: the rainy season and the dry season.

Temperatures typically range between 25°C and 32°C year-round, and the island enjoys plentiful sunshine for much of the year. Understanding these seasonal patterns can help you plan the perfect time to visit.

SeasonPeriodCharacteristics

Rainy Season

Usually September – November

This period sees increased rainfall, often in the form of short, heavy showers, usually in the late afternoon or evening. Mornings are often clear. The landscape is lush and green during this season.

Dry Season

Generally December – August

Rainfall is less frequent, and the weather is typically sunny and pleasant. This is the best time for beach activities, island hopping, and exploring the outdoors.

Temperature and Humidity in Langkawi

Langkawi experiences a tropical climate influenced by the surrounding Andaman Sea. The island enjoys warm temperatures and high humidity throughout the year, creating a lush, vibrant environment.

Average Temperature

The annual average temperature in Langkawi typically ranges between 25℃ and 32℃. Temperatures remain fairly consistent year-round, with only slight variations between seasons.

  • The warmest period generally occurs between February and May, when average daily highs often exceed 32℃. April is typically the hottest month, with an average high of 32℃ and an average low of 26℃.
  • The cooler period is usually from November to January, when average daily highs remain below 31℃. December is often the coolest month, with an average low of 25℃ and an average high of 30℃.

Humidity

Langkawi maintains consistently high humidity levels throughout the year, with an annual average around 80%.

  • During the rainy season (September to November), humidity levels can rise above 90%, especially after heavy showers.
  • In the dry season (December to August), humidity typically ranges between 70% and 80%, though the sea breeze often provides some relief, particularly along the coast.
❤️If your're traveling to Malaysia, don't forget to purchase an eSIM in advance to stay connected smoothly during your trip. Check out this blog for more informationn. How to Use an eSIM.
Malaysia eSIM 3 Day
  • CountryMalaysia
  • Package Option1GB/Day
  • Number of Days3 Day
  • PriceMYR13.35
Malaysia eSIM 7 Days
  • CountryMalaysia
  • Package Option1GB/Day
  • Number of Days7 Days
  • PriceMYR23.81
Malaysia eSIM 15 Days
  • CountryMalaysia
  • Package Option1GB/Day
  • Number of Days15 Days
  • PriceMYR48.68

Check the Weather Forecast

MET Malaysia

Image from METMalaysia - Home

For official weather updates in Malaysia, including Langkawi, you can visit the MET Malaysia website: https://www.met.gov.my.

This website provides reliable and up-to-date weather information to help you plan your trip. Key features include:

  • Live weather updates for Langkawi and other regions
  • Short-term and long-term weather forecasts
  • Rain radar and satellite imagery
  • Air quality and ocean condition forecasts
  • Extreme weather warnings and disaster management information

As an authoritative source of weather information endorsed by the Malaysian government, this site is highly recommended for travellers and locals alike. Checking it regularly will help you make informed decisions about your activities and travel plans in Langkawi.

❤️ If you’re travelling to Malaysia, consider staying in Pantai Cenang: this lively beachfront area in Langkawi is known for its wide range of hotels, beach resorts, restaurants, and shops. If you want to experience the island’s vibrant atmosphere and beautiful beaches, Pantai Cenang is an excellent choice. Book your hotel on Trip.com to enjoy the best deals!

Hotel Popular in Langkawi

5 star

9/10Great547 Ulasan
Langkawi|14.76km dari pusat bandar
Highly recommended resort with stunning views! This gigantic resort offers breathtaking views that perfectly combine the rainforest, mountains, and beach. With more than 400 chalets, the layout is unique—some rooms are nestled on the mountainside, while others are built right above the seawater. Because the property is so vast, you do need a shuttle buggy to get around, which is quite convenient. Dining: The breakfast buffet is tasty with plenty of options. However, the Chinese restaurant is a bit pricey, and while the beach bar serves decent pizzas, we unfortunately missed out on the Thai restaurant as it was closed during lunchtime when we wanted to try it. Rooms & Amenities: The rooms are slightly run-down but generally well-maintained. Due to the natural surroundings, there is high humidity inside, meaning swimming suits don’t dry easily overnight. Also, the mattress we had sagged a bit in the center. Overall Verdict: Despite the minor room flaws, it’s an incredible stay. I would definitely recommend it to my friends!
Dari€ 93
9.1/10Great1350 Ulasan
Pantai Cenang Langkawi|10.39km dari pusat bandar
I've stayed at many resorts over the years, but Pelangi Beach Resort & Spa is one of the very few places that has left such a lasting impression on me. As someone who visits Langkawi a minimum of twice a year, I can confidently say that I have finally found my forever place to stay whenever I'm on the island. What makes Pelangi truly special is its people. The level of service is comparable to that of a world-class luxury resort. Every staff member I encountered was warm, professional, attentive, and genuinely cared about ensuring guests had a wonderful stay. In fact, I cannot single out one person for special recognition because every single person was exceptional. From the front desk and housekeeping teams to the restaurant staff and those maintaining the resort grounds, every interaction was consistently outstanding. The exceptional service is not limited to a few individuals; it is clearly part of the resort's culture and something the management should be incredibly proud of. The rooms are comfortable, well-maintained, and provide the perfect retreat after a day of exploring Langkawi. However, prospective guests should understand what makes Pelangi unique. The accommodation consists of traditional Malay-style wooden chalets rather than concrete hotel blocks. The resort has a wonderfully authentic kampung feel, which is a large part of its charm. With wooden structures, some sound naturally travels in and out more than it would in a modern concrete building. For me, this adds to the character and authenticity of the experience rather than taking away from it. What I particularly love is that while the chalets retain their traditional architecture and charm on the outside, the interiors are modern, comfortable, and equipped with everything you need for a relaxing stay. It's a wonderful blend of heritage and comfort that feels distinctly Langkawi. The resort grounds are immaculate, beautifully landscaped, and absolutely spotless. Everywhere you look, there is clear attention to detail and pride in maintaining the property to a very high standard. Walking around the property is a pleasure in itself. Breakfast is good, with an adequate variety of options to cater to different tastes and preferences. There is always something enjoyable to start the day, whether you prefer local favourites or international selections. If I had to offer one tiny piece of constructive feedback, it would be regarding the air conditioning. During my stay, it was clearly working hard to cool the entire room and did a decent job, but the tropical Langkawi heat can be challenging. Thankfully, the ceiling fan complemented the air conditioning perfectly and helped keep the room comfortable throughout my stay. Combined with its stunning beachfront setting, beautiful grounds, comfortable accommodation, authentic charm, and genuinely outstanding hospitality, Pelangi Beach Resort & Spa delivers an experience that keeps me coming back year after year. For me, this resort is no longer just a place to stay. It has become my home away from home in Langkawi, and I genuinely look forward to every return visit. After many trips to the island, I can confidently say that I have found my forever resort. If you're looking for authentic Malaysian charm, exceptional staff, a beautiful beachfront location, and a resort that feels both luxurious and welcoming, Pelangi Beach Resort & Spa is an easy recommendation. I cannot wait for my next stay.
Dari€ 134
9.4/10Amazing205 Ulasan
Pantai Kok Langkawi|11.58km dari pusat bandar
Let's start with the conclusion: Overall, it was great 👍 and I'd consider going back! Pros: 😀 1. The service was absolutely perfect! I visited all the restaurants, the pool, the kids' club, the shops – all public facilities – and the staff were incredibly dedicated. They tried their best to meet any request, and they asked very detailed questions, especially when interacting with children, who they were super friendly to! I only encountered three staff members who spoke Chinese: the chef and a server at the Chinese restaurant, and a lady at the kids' club! 2. Even though it was a bit muggy, I surprisingly didn't get a single mosquito bite! Not one mosquito bump on our family of three! I brought so much mosquito repellent, but it was all for nothing! 3. Many European and North American families stay at this hotel, so the food has been adapted a bit, especially the Chinese food, haha! But the quality is still okay! The Chinese breakfast at Haiyan Restaurant is better than their dinner! Cons: 😡 1. We stayed on the first floor in Area 6, and one night the equipment noise was incredibly loud – ridiculously loud! I really wanted to call and complain at the time, but it was the middle of the night and my child was fast asleep, so I let it go. Everyone should definitely avoid that area! 2. On the first day, we left a tip on the nightstand, and they even coiled my phone charger neatly, and arranged the paper airplanes my child made in a row. The tidying was incredibly meticulous, the most detailed and best I've ever experienced in a luxury hotel! But on the second day! We didn't leave a tip, and lo and behold, a bunch of shower hair in the shower caddy wasn't cleaned up, which I didn't expect! Do they really differentiate service that much?
Dari€ 527
8.9/10Very Good320 Ulasan
Langkawi|8.26km dari pusat bandar
Objective review: Pros: Most hotel staff were warm, friendly, and enthusiastic. The location boasts beautiful scenery, with wildlife nearby, and it's very close to the jetty. There are also many dining options in Kuah Town. The spa was excellent, though a bit pricey! Cons: The hotel's facilities are outdated, and cleanliness was just average. The toilet had a slight odor, and the sheets had stains, which I later asked staff to replace. The biggest issue is the soundproofing. If you're easily stressed or a light sleeper, seriously consider my advice and avoid this hotel. Perhaps I was unlucky, but for four nights, a Middle Eastern family with two crying children stayed across from us, and their wailing continued past midnight. It was truly frustrating. Thankfully, the platform provided timely feedback and intervention, and the hotel manager offered some gifts and earplugs, but there were still several difficult hours at night. I think a better solution would have been to help us move to a more suitable room, but the manager refused, stating that twin rooms were fully booked. This is definitely incomparable to hotels with excellent service awareness in China. Another major pitfall: The seafood at the hotel's restaurant, Tide, was not fresh and very expensive. Definitely avoid it; don't take my word for it, go try it yourself. My daughter had diarrhea that night, and the hotel later offered some discount compensation. Communicating with foreigners is exhausting, so I won't dwell on it. Finally, since this was a family trip, we focused more on the happy moments. Despite the imperfections, let's just think less about them~ I wish everyone gets to see the beautiful natural scenery of Langkawi.
Dari€ 148
9.7/10Amazing132 Ulasan
Tanjung Rhu Beach Langkawi|10.75km dari pusat bandar
Four Seasons Langkawi is the kind of hotel that makes you slow down and relax. Nestled on Tanjung Rhu peninsula, it's surrounded by lush tropical nature, with its architecture blending seamlessly into the environment. There's no noise here, just the sea breeze, verdant greenery, and impeccable service.
Dari€ 558

Show more

Business travel

8.3/10Very Good533 Ulasan
Pantai Tengah Langkawi|12.22km dari pusat bandar
We loved our stay in Resort World Langkawi. It was the first time with our baby. The infinity pool was amazing. Highly recommend it. There are two restaurants for dinner. We dined in the Indian one. They provide room service. The breakfast was also very good
Dari€ 34
8.4/10Very Good578 Ulasan
Pantai Tengah Langkawi|11.27km dari pusat bandar
The room for 700+ a day, including breakfast, was really bad. It was damp, the air conditioner was old and noisy, there were no towels, the light switches were very old, the room had virtually no decoration, the sofa was ancient, there was no showerhead, the fridge was loud, and there was only one power outlet in the entire room. The breakfast was good, and the hotel's common areas and beach were nice. The sheets were sticky, and the duvet wasn't fluffy. Honestly, I think it's worse than a 300-a-day room in China.
Dari€ 69
7.7/10Good883 Ulasan
Kuah Town Langkawi|6.55km dari pusat bandar
Located in Kuah, this hotel was quiet and reasonably priced. Breakfast was priced at $7.85 per head for a basic buffet. The roof top bar area allowed for a 360 degree view of Kuah Town. And to the far end of the bar was a mini infinity pool that backdrops the calmness of the sea . The rooms had an old setting , clean and basic. And yet ,fullfilled the need for a good sleep . Location wise, apart from bustling Chenang, this hotel had quiet surroundings. Every Wednesday , there is a night market just below. Around the vicinity there are massage parlours , eateries . Prices are lower in Kuah than in Chenang and that was the plus point of this hotel.
Dari€ 33
7.7/10Good535 Ulasan
Kuah Town Langkawi|4.81km dari pusat bandar
We stayed at this hotel for two nights and mostly used the room just to sleep. Overall, we had a pleasant stay. The view from the room was beautiful, the bed was comfortable, and the room itself was cozy and had everything we needed. The soundproofing was also quite good, which made it easy to get a good night’s sleep. We had breakfast included, and it offered everything you would normally expect from a standard European breakfast. Nothing extraordinary, but perfectly good and satisfying. I would like to mention a few small points for future guests, without lowering my rating because they didn’t significantly affect our stay. The room cleanliness could be improved. The bed linens and towels were perfectly clean, but the decorative pillows, curtains, and parts of the bathroom didn’t seem as clean as they could have been. I’d rate the overall room cleanliness around 5/10. Also, there were no toothbrushes provided, and the toiletries were not replenished in sufficient quantities for a two-night stay. I would recommend bringing your own toothbrush and personal hygiene items just in case. Despite these minor issues, we enjoyed our stay. The staff were friendly and welcoming, and the hotel left a positive overall impression. Thank you for your hospitality!
Dari€ 48
8.6/10Very Good344 Ulasan
Pantai Tengah Langkawi|11.51km dari pusat bandar
The service was enthusiastic, but the facilities were old and the room was small. The fridge was full of water and mold, and the kettle was leaking. Breakfast was terrible, with limited options and the worst quality I've ever had in a hotel. The ingredients were extremely poor. Even the fruit was tasteless and not sweet; the pineapple was so sour it was inedible, the waffles tasted sour, and the only vegetable was stir-fried cabbage. There was absolutely nothing redeemable about it. The only edible items were the freshly made paratha and omelets.
Dari€ 85

Show more

Breakfast

9.2/10Great189 Ulasan
Langkawi|9.14km dari pusat bandar
Love the services! The breakfast was amazing, there are lots of choices. And they also park the car for you. They also helped with carrying your luggage from the car to the room. The room is also spacious and clean! It had a comfortable table to work. You can even request for a memory foam pillow which is very comfortable. Overall, I really enjoyed the hospitality of the hotel.
Dari€ 428
8.6/10Very Good352 Ulasan
Kuala Muda Langkawi|9km dari pusat bandar
I had a wonderful stay at Ombak Villa Langkawi. The room was comfortable, the surroundings were beautiful, and the overall atmosphere made for a relaxing staycation. The facilities were great, and I truly enjoyed my time here. However, there are a few areas that could be improved. The check-in experience was disappointing. Although I had booked my room four days in advance, I still had to wait almost an hour before my room was ready. What made it more frustrating was that no apology or explanation was given by the staff for the delay. Another area that needs improvement is the Wi-Fi connection, which was quite unstable during my stay. Overall, I had a great experience and would still recommend Ombak Villa Langkawi. With better customer service during check-in and a more reliable Wi-Fi connection, the experience would be even better.
Dari€ 57
9.4/10Amazing300 Ulasan
Tanjung Rhu Beach Langkawi|11.72km dari pusat bandar
⭐⭐⭐⭐⭐ A very pleasant stay! I had a really enjoyable experience staying at this hotel. The room was clean, spacious and comfortable, and everything was well maintained. The bed was especially comfortable, making it easy to get a good night’s sleep after a long day. The staff were also very friendly, helpful and professional throughout my stay. Check-in and check-out were smooth and hassle-free. I also really enjoyed the breakfast — there was a good variety of food and everything tasted great. The location was convenient as well, with many places nearby. Overall, the hotel offered great service, comfort and value for money. Definitely a place I would recommend, and I wouldn’t hesitate to stay here again. ❤️
Dari€ 157
8.3/10Very Good596 Ulasan
Kuah Town Langkawi|5.12km dari pusat bandar
Although it's an older hotel, it's been renovated. The room was very spacious and even had a balcony. The front desk gave us a sea view room, and the separate wet and dry areas in the bathroom were very convenient. The hotel's own swimming pool is also beautiful. We stayed for three days, and it was super easy to find food nearby; convenience stores and malls were all within walking distance. We could try a different place to eat every day and still not run out of options. Prices here are much more affordable than in Cenang, offering great value for money, and it's not far to get anywhere by taxi.
Dari€ 30
8.4/10Very Good814 Ulasan
Pantai Cenang Langkawi|10.36km dari pusat bandar
⭐⭐⭐⭐⭐ Perfect for families and friends – everything is right next door! Just checked out after 3 amazing days at Adya Hotel Chenang. The location is unbeatable, everything we needed was right next door: the beach, street food, malls, and duty-free shops. We didn't need a Grab or car at all! The beach is beautiful with lots of fun activities, and there are plenty of restaurants around. We met friendly people from all over the world. Had the best time with my family. Highly recommended, especially for families with young kids. We'll definitely be back!
Dari€ 23

Show more

Show more

Best Time to Visit Langkawi

The best time to visit Langkawi is during the dry season (December to August), when rainfall is minimal, skies are clear, and the weather is generally sunny and pleasant. Daytime temperatures typically range from around 25°C to 32°C, while nighttime temperatures stay around 24°C.

The favourable weather during this period is ideal for enjoying beach activities, island hopping, snorkelling, and exploring Langkawi’s natural attractions, such as Langkawi Sky Bridge, Kilim Geoforest Park, and Telaga Tujuh Waterfalls.

Outdoor Activities During Sunny and Warm Weather

On a bright and sunny day in Langkawi, you can enjoy a wide variety of outdoor activities. Here are some top recommendations:

Explore the Langkawi Sky Bridge

Langkawi Sky Bridge

One of Langkawi’s most famous attractions, the Langkawi Sky Bridge offers spectacular panoramic views of the island and the Andaman Sea. The curved pedestrian bridge, suspended high above the jungle canopy, provides a unique vantage point for photography and sightseeing.
Recommended visit duration: 1–2 hours
Admission fee: Approximately RM10–RM15

Island Hopping Tour

A must-do activity in Langkawi is an island hopping tour. Typically, the tour includes visits to Pulau Dayang Bunting (Lake of the Pregnant Maiden), Pulau Beras Basah, and Pulau Singa Besar, where you can enjoy swimming, sunbathing, and eagle watching.
Recommended visit duration: Half day (about 4–5 hours)
Estimated cost: RM50–RM100 per person (depending on package)

Visit Pantai Cenang

Spend a relaxing day at Pantai Cenang, Langkawi’s most popular beach. The lively strip offers golden sands, crystal-clear waters, and plenty of beachfront cafés and bars. It’s an ideal spot for swimming, sunbathing, and enjoying a beachside sunset.
Recommended visit duration: Half day to a full day
Estimated cost: Free (excluding optional activities)

Have Fun at Splash Out Langkawi

Splash Out Langkawi is a family-friendly water park offering a variety of thrilling water attractions, including slides, splash zones, and a wave pool. It’s a great way to cool off and have fun, especially if you’re travelling with children.
Recommended visit duration: Half day to a full day
Admission fee: Approximately RM75 for adults, RM55 for children

Visit Langkawi Wildlife Park & Bird Paradise

Langkawi Wildlife Park & Bird Paradise

Langkawi Wildlife Park & Bird Paradise offers a fun and educational experience for visitors of all ages. The park features a walk-in aviary, where you can interact with various species of birds, as well as sections showcasing reptiles, mammals, and freshwater fish. Hands-on activities like feeding animals make this a great option for families.
Recommended visit duration: Half day to a full day
Estimated cost: Approximately RM50–RM75 per person

Visit Telaga Harbour Marina

Telaga Harbour Marina is a picturesque harbour and marina known for its Mediterranean-inspired architecture and charming waterfront setting. It’s a lovely place to stroll along the promenade, admire luxury yachts, and enjoy seaside dining. You can also arrange for boating trips, yacht charters, or sunset cruises from here.
Recommended visit duration: Half day to a full day
Estimated cost: Free to explore; costs vary for boating or cruise activities

❤️Tip: Want to discover more interesting places in Malaysia? Check out the Attraction in Malaysia blog and start planning your vacation now!

Indoor Activities During Rainy Days

Even on a rainy day in Langkawi, there are plenty of enjoyable indoor activities to keep you entertained. Here are some great options:

Cultural Experience

Visit a museum

Langkawi offers several interesting museums where you can learn more about the island’s rich history and culture. Notable options include the Langkawi Maritime Museum, the Rice Garden Museum (Laman Padi Langkawi), and the Galeria Perdana, which houses an impressive collection of gifts and awards received by Malaysia’s former Prime Minister. A museum visit is a perfect way to explore local heritage while staying dry.
Recommended visit duration: 2–3 hours

Visit Langkawi Underwater World

Langkawi Underwater World

Underwater World Langkawi, located at Pantai Cenang, is one of Southeast Asia’s largest marine and freshwater aquariums. It features themed sections such as Rainforest, Temperate, and Sub-Antarctic zones. You’ll encounter penguins, sharks, rays, turtles, and a variety of tropical fish, making it a fantastic activity for families and marine-life enthusiasts alike.
Recommended visit duration: 2–3 hours

Visiting Religious and Cultural Sites

Visit a Mosque

Langkawi is home to several beautiful mosques, such as Al-Hana Mosque in Kuah Town. Visiting these mosques provides insight into local Islamic architecture and culture. Please remember to dress modestly and follow the proper etiquette when entering.
Recommended visit duration: 1–2 hours

Visit a Hindu Temple

Sri Maha Mariamman Devasthanam Temple, located in Kuah Town, is a vibrant and intricately decorated Hindu temple. Exploring this spiritual site offers a glimpse into the island’s multicultural fabric.
Recommended visit duration: 1 hour

Shopping and Entertainment

Visit a Shopping Mall

While Langkawi is known more for its natural beauty, it also offers duty-free shopping, which is perfect for a rainy day. You can explore places like Langkawi Parade Megamall or Jetty Point Complex, where you’ll find a selection of duty-free chocolates, perfumes, liquor, fashion, and souvenirs.
Recommended visit duration: 2–3 hours

Experience Indoor Activities

Several resorts and entertainment centres offer indoor activities such as cooking classes, batik painting workshops, and craft-making experiences. These cultural workshops allow you to learn a new skill and take home a handmade souvenir.
Recommended visit duration: 2–4 hours

Leisure and Relaxation

Enjoy Local Cuisine

Langkawi is rich in culinary delights. On a rainy day, visit a local restaurant, café, or beachside bar to savour specialities like seafood laksa, nasi dagang, grilled fish, or Langkawi’s famous duty-free chocolates. It’s also a great time to enjoy a warm cup of coffee or tea while watching the rain.
Recommended visit duration: 1–2 hours

Get a Spa or Massage

Langkawi is renowned for its luxurious spas and wellness centres. Treat yourself to a spa session or a traditional Malay massage, perfect for unwinding on a rainy afternoon and relieving any travel fatigue. Many spas offer settings surrounded by nature, creating a serene atmosphere even if it’s raining outside.
Recommended visit duration: 1–2 hours

Langkawi Weather Summary

Dataran Lang

Overall, Langkawi enjoys a warm tropical climate, making it a great destination to visit year-round. You can experience the island’s natural beauty and laid-back charm in any season. However, if you prefer to avoid heavy rainfall and make the most of outdoor activities, it is best to plan your visit during the dry season.

❣️Read the following article to get the best deals:

Latest Trip.com Promo Code, Coupons, Flight Deals & Hotel Discounts for Malaysia

Latest Trip.com Flight Deals & Promotions for Malaysia

Latest Trip.com Credit Card Promo Codes, Deals, Coupons for Malaysia

FAQs: Weather in Langkawi

Disclaimer: This article has been provided by an individual contributor or third party platform. If there is any discrepancy regarding the copyright, please contact us directly and we will delete the content immediately.
Ferocious_Squirrel

Ferocious_Squirrel

Travel Content Creator

Lihat profil

Travel and nature these are my happy places. I write to share my favorite spots, hidden gems, and travel tips, so you can live your own adventure in style.

153 artikel
Dining Enthusiast Travel Storyteller
> >
Weather in Langkawi