Short answer
The best time to visit Krabi is December to March, when the Ko Lanta weather station records only 2 to 8 rainy days a month: 7.8 in December, 2.6 in January, 1.8 in February and 4.8 in March, according to the 1991 to 2020 normals. April is hotter and starts to turn wet. The rainy season runs from May to October, with August the wettest month at 342 mm. Our 4 Islands day from Ao Nang is from $35 per person.
December to March is the best stretch
The answer from the numbers: pick December to March. The World Meteorological Organization's 1991 to 2020 normals for the Ko Lanta station, the Krabi-province station in the set, show 7.8 rainy days with at least 1 mm in December, 2.6 in January, 1.8 in February and 4.8 in March. Rainfall in those months is 64.6, 31.0, 24.1 and 69.0 mm. Compare that with 342.0 mm in August.
The Thai Meteorological Department's winter outlook, issued on 27 September 2024, fits the picture. It expected rain over only 10 to 20 per cent of the Andaman side from December until the middle of February, against 40 to 60 per cent until November, with waves of 1 to 2 metres in the Andaman Sea in the earlier period. These are seasonal outlooks for one year, but they match the normals.
Averages hide the spread, and the same table shows it. The lowest February total in the 30 years is 0 mm and the highest 87.8 mm, while August ranges from 91.9 to 675.5 mm. In other words, the dry months are reliably dry, and a wet month can still bring a run of bright days. Use the averages to choose a season and keep a spare day for the rest.
How hot is it in the best months
Dry means warmer, and the heat builds towards spring. The average daytime high is 31.4 degrees in December, 32.6 in January, 33.5 in February and 33.9 in March, the hottest month of the year. Night lows hold at 23.9 to 24.7 degrees. Relative humidity is lowest in this stretch, 74.2 per cent in February against 85.7 in October.
If you prefer milder heat, December and January are the gentler months. If you want the driest days and do not mind 33 or 34 degrees by day, February and March suit you better. Either way, bring sun protection for boat days.
April: hotter, and the rain starts to return
April is a turning month. The Ko Lanta normals give an average high of 33.8 degrees, still among the hottest of the year, but rain rises to 121.6 mm on 9.0 days, up from 69.0 mm and 4.8 days in March. Humidity climbs to 79.8 per cent. You can still have a bright week; the average simply stops promising it.
For island days, April is a reasonable compromise: less rain risk than the wet season, more than in March. Keep one spare day for the boat trip. Our Krabi 4 Islands tour price guide explains what the day costs and what the park fee adds.
May to October is the rainy season
From May the numbers jump. May brings 227.5 mm, June 285.9 mm, July 288.5 mm, August 342.0 mm, September 319.4 mm and October 297.5 mm, on 14 to 18 rainy days a month. October has the most rainy days, 17.9. Together the six months bring about 79 per cent of the station's 2,220 mm yearly total.
The sea follows. In an advisory dated 27 May 2026 the Thai Meteorological Department expected waves of about 2 metres from Krabi downward and 2 to 3 metres from Phuket northward, higher in thundershowers. Boats still run on calm days, and the national park can shut beaches on rough ones. Our guide to Krabi in the rainy season covers closures, tours and refunds.
November and December: the shoulder that improves
November is the bridge back to the dry season. Rain falls to 148.4 mm on 12.3 days, about half of October's 297.5 mm, and in December to 64.6 mm on 7.8 days. The Thai Meteorological Department's 2024 outlook still expected thunder rain over 40 to 60 per cent of the Andaman side until November, easing afterwards.
The marine-park season follows the same arc. On 15 October 2026 the Department of National Parks said the Andaman season was officially open again after the seasonal closure, and it named Hat Noppharat Thara–Mu Ko Phi Phi and Mu Ko Lanta among the parks ready for visitors. So for November expect showers, with waves of 1 to 2 metres in the Department's outlook, and a drier December. Compare with Phuket in November.
What the seasons mean for the island boat days
Our 4 Islands day is from $35 per person and the Hong Islands day from $40, both by speedboat from Ao Nang. The park fee is paid in cash at check-in: 200 baht per adult and 100 per child for the 4 Islands, 300 and 150 for the Hong Islands. In every month the same rule applies: if the sea is unsafe, the operator moves the trip to another date or refunds it. Jellyfish appear in some seasons, so long swimwear and water shoes help.
The Tup sandbar to Chicken Island appears at low tide and is under water at high tide, a matter of the day's tide and not the season. Maya Bay, on a different trip, closes every year from 1 August to 30 September, as our Maya Bay rules guide explains. For the stops and times of our own days, see the tour schedule.
One practical point for planning: hotel pickup covers Ao Nang and the Krabi area between about 7:30 and 8:40 am, and guests staying at Railay and Tonsai are collected from the beach. There is no pickup from Phuket, Koh Lanta or Phi Phi, so choose your base with that in mind.
Which month for which kind of trip
For the driest days and the most reliable boats, choose February or March, or January for slightly milder heat. For a warm week with showers, choose April or November, and keep your boat day flexible. For the wet months, go in only if you can accept the weather, and compare the Gulf coast, which is drier from June to September, in our best time to visit Koh Samui guide.
If you are still choosing between places, the Phuket or Krabi comparison and the Ao Nang or Railay guide cover the base. Whatever the month, send us your dates and hotel on WhatsApp; we confirm availability, the pickup time and the total before you pay.
Practical checklist
- Aim for December to March for the driest weather, and February if you want the fewest rainy days.
- Add a spare day to your week if you travel in April, May to October or November.
- Bring cash for the national park fee: 200 baht per adult on the 4 Islands day, 300 on the Hong Islands day.
- Pack sun protection, a hat and a dry bag for boat days in every month.
- Bring water shoes and long swimwear in case jellyfish are reported.
- Avoid Maya Bay plans between 1 August and 30 September.
Questions and answers
What is the best month to visit Krabi?
February is the driest, with 24.1 mm of rain on about 2 days in the 1991 to 2020 normals. January and March are close behind. March is the hottest, with an average high of 33.9 degrees.
What is the rainiest month in Krabi?
August, with 342.0 mm. October has the most rainy days, 17.9, and September follows with 319.4 mm and 17.0 days. May to October together bring about 79 per cent of the year's rain.
Is Krabi good in November?
It is improving. Rain falls to 148.4 mm on 12.3 days, down from 297.5 mm in October. The Thai Meteorological Department's outlook still expected showers over 40 to 60 per cent of the Andaman side until November.
Can you visit the islands in the rainy season?
Yes, on calm days. The national park shuts beaches when the sea is rough, and our operator moves or refunds a trip if the sea is unsafe. See the rainy season guide for details.
How hot is Krabi in April?
The average daytime high is 33.8 degrees and the night low 25.1 degrees, with rain rising to 121.6 mm on 9.0 days, according to the 1991 to 2020 normals.
Is Hong Islands open all year?
We found no official full-season closure for the Hong Islands or Poda. The park can close sites for days when waves are high, as it did in September 2024, so keep a spare day.