Thailand in April: Weather, Crowds and What to Expect

April is defined by one event: Songkran. Thailand’s New Year water festival (April 13-15) is one of the most spectacular celebrations in Southeast Asia and a genuine reason to visit despite the extreme heat. Outside of Songkran week, April is the hottest month of the year and the beginning of the monsoon transition on the Andaman Coast.

Weather by Region

Bangkok is at its hottest — daytime temperatures regularly hit 37-40°C with high humidity. The city can feel oppressive during the day. Air-conditioned shopping malls, the BTS/MRT system, and river boats become essential rather than optional. Evening temperatures drop to a more manageable 28-30°C.

Chiang Mai and the north are extremely hot (35-38°C) and burning season continues through early April, though air quality typically improves by mid-month as rains begin. Chiang Mai hosts one of the largest Songkran celebrations in the country — the moat around the old city becomes the epicentre of the water fight.

Andaman Coast (Phuket, Krabi, Koh Phi Phi) is hot with the first pre-monsoon showers arriving in late April. The Similan Islands remain open through April but close in May. Sea conditions are still diveable but deteriorating. Koh Lipe ferry services continue but reduce frequency toward the end of the month.

Gulf Coast (Koh Samui, Koh Phangan, Koh Tao) is hot and humid with occasional afternoon thunderstorms. Seas remain calm. The Gulf Coast handles the transition period better than the Andaman side and remains swimmable throughout April.

Songkran Festival (April 13-15)

Songkran is the highlight of Thailand’s calendar. The official holiday runs April 13-15, but celebrations extend to a full week in major cities. Bangkok’s Khao San Road, Silom Road, and Siam area become massive water-fight zones. Chiang Mai’s moat-ringed old city hosts perhaps the most intense celebrations. Phuket’s Patong Beach and Old Town run large events.

During Songkran, expect water thrown from every direction — protect electronics in waterproof bags. Public transport is disrupted. Accommodation prices spike 50-100% for the festival dates in popular areas. Book at least 6-8 weeks ahead if visiting specifically for Songkran.

Beyond the water fights, Songkran has deep cultural roots: temple visits, pouring water over Buddha images, and paying respect to elders are integral parts of the celebration. Temples host merit-making ceremonies throughout the period.

Diving Season

The last month for Similan Islands liveaboards — the national park closes on May 1. April liveaboards can be discounted compared to peak February-March pricing. Koh Tao remains open year-round, and April diving is decent with warm water (29-30°C) though visibility begins to decrease.

Prices and Crowds

April is a split month. The Songkran period (April 10-17) commands high-season prices for accommodation and domestic flights. Outside Songkran, April is excellent value — Western tourist numbers drop sharply due to the heat, and beach resorts offer significant discounts. Late April is one of the cheapest times for Phuket and Krabi accommodation.

Where to Go in Thailand in April

• Bangkok: Bangkok city guide
• Chiang Mai: Chiang Mai guide
• Phuket: Phuket guide
• Koh Samui: Koh Samui guide
• Koh Phangan: Koh Phangan guide
• Krabi: Krabi guide

Planning

See the best time to visit Thailand for a full seasonal comparison, or the Thailand budget guide for cost planning. Browse Thailand tours and experiences — particularly useful for Songkran festival tours and island activities.