Summary
Seasonal Fires in Northern Thailand
Each year, fires—some natural and many illegal—get out of control in Northern Thailand, causing horrible smoke and haze to choke Chiang Mai, Chiang Rai, and Pai. Particulate levels consistently reach dangerous thresholds, prompting locals to wear masks.
March and April are two of the worst months for pollution from fires. While air quality should improve by June, a delayed monsoon may keep particulate matter a health risk. Therefore, travelers with respiratory conditions should check the situation before planning visits to Chiang Mai or Pai.
Koh Lanta Begins Seasonal Slowdown
As storms start affecting the Andaman coast, many businesses on the popular island of Koh Lanta close for the season. While the island does not completely “close,” dining and drinking options outside resorts become limited. Consequently, many beautiful beaches may become cluttered due to washed ashore debris.
Thailand Weather in June
June, along with May, marks the beginning of Thailand’s monsoon season; the weather will be hot, humid, and increasingly wet. However, there will still be plenty of sunshine for enjoying a vacation in Thailand.
Interestingly, average rainfall in June is slightly less than in May. This dip in precipitation could be seen as the Southwest Monsoon taking a short breath before escalating into a stormy climax in September and October.
Average High / Low Temperatures
- Bangkok: 94 F (34.4 C) / 79 F (26.1 C)
- Chiang Mai: 91 F (32.8 C) / 76 F (24.4 C)
- Phuket: 91 F (32.8 C) / 78 F (25.6 C)
- Koh Samui: 91 F (32.8 C) / 78 F (25.6 C)
Rainfall in June
- Bangkok: 7.3 inches (average of 16 rainy days)
- Chiang Mai: 2.4 inches (average of 17 rainy days)
- Phuket: 7.7 inches (average of 18 rainy days)
- Koh Samui: 4 inches (average of 14 rainy days)
Thailand Weather in July
In July, the frequency of rainy days increases; however, temperatures remain high. Air quality typically improves, but it can still be very hot.
Average High / Low Temperatures
- Bangkok: 93 F (33.9 C) / 79 F (26.1 C)
- Chiang Mai: 90 F (32.2 C) / 75 F (23.9 C)
- Phuket: 90 F (32.2 C) / 78 F (25.6 C)
- Koh Samui: 90 F (32.2 C) / 77 F (25 C)
Rainfall in July
- Bangkok: 8.7 inches (average of 17 rainy days)
- Chiang Mai: 2.6 inches (average of 19 rainy days)
- Phuket: 8 inches (average of 20 rainy days)
- Koh Samui: 5 inches (average of 14 rainy days)
Thailand Weather in August
Showers grow stronger throughout August. Islands in the Samui Archipelago typically receive slightly less rain than the west coast (Phuket, Koh Lanta, and Koh Phi Phi).
Average High / Low Temperatures
- Bangkok: 93 F (33.9 C) / 78 F (25.6 C)
- Chiang Mai: 89 F (31.7 C) / 75 F (23.9 C)
- Phuket: 90 F (32.2 C) / 78 F (25.6 C)
- Koh Samui: 91 F (32.8 C) / 77 F (25 C)
Rainfall in August
- Bangkok: 7.3 inches (average of 20 rainy days)
- Chiang Mai: 4.2 inches (average of 21 rainy days)
- Phuket: 8 inches (average of 19 rainy days)
- Koh Samui: 2.8 inches (average of 15 rainy days)
What to Pack
Always have a means to waterproof your luggage, backpack, phone, and passport for unexpected monsoon showers. Waterproof bags are readily available locally.
Even during the rainy season, a poncho or umbrella can be bought easily, but quality rain gear should be lightweight without insulation.
Opt for breathable, loose-fitting clothing for those humid days while exploring urban areas. If Bangkok’s urban heat becomes overwhelming, consider nearby escapes to cooler locations.
Summer Events in Thailand
Several royal birthdays occur during the summer, but they are not as extravagant as festivals like Songkran in April and Loi Krathong in November.
- King Maha Vajiralongkorn’s Birthday (July 28): This notable event is celebrated on July 28, distinct from former King Bhumibol’s birthday on December 5.
- Queen Sirikit’s Birthday (August 12): As Mother’s Day in Thailand, cultural shows and a candlelight ceremony are held, often with fireworks.
- Buddhist Lent (dates vary): Various Buddhist public holidays take place in June and July, where alcohol sales can be restricted. Observing good temple etiquette becomes particularly important during this time.
Summer Travel Tips
- Rain is generally less intense for islands like Koh Samui, Koh Tao, and Koh Phangan.
- The Chao Phraya River in Bangkok can experience flooding, which is usually not severe in summer; however, allow additional time for flights.
- Low-season hotel rates may be negotiable as tourist crowds diminish later in the summer.
- As stagnant water accumulates due to rain, mosquito populations rise. Take precautions against bites, particularly in the evening.
The Thai Islands in Summer
The climate varies across the Thai islands depending on their location. For example, Koh Chang in the Gulf receives the highest rainfall during June, July, and August. However, Koh Samui and nearby islands usually experience manageable rain until around October, while the wettest months are often October, November, and December.
In contrast, the monsoon affects Phuket and the Andaman islands, such as Koh Phi Phi and Koh Lanta, around May, with rainfall decreasing significantly by December. After June, islands like Koh Lanta tend to close as storms roll in, resulting in fewer dining and lodging options.
Parties in the Summer
Although summer is characterized as the “low season” in Thailand, party islands remain vibrant with activity. University students leverage their breaks for backpacking adventures and revelry on islands such as Koh Tao, Koh Phi Phi, and at Haad Rin Beach on Koh Phangan. Traveling families also take advantage of this period while their children are free from school commitments.
Notably, Malaysia’s Perhentian Islands and Indonesia’s Gili Islands have favorable weather during the summer, attracting more travelers seeking fun in the sun. Bali, known for its nightlife, sees an uptick in visitors eager to embrace the dry season.
The Amazing Thailand Grand Sale
During the summer months, the Tourism Authority of Thailand organizes the Amazing Thailand Grand Sale from mid-June to mid-August to attract tourists amidst the low season. Participating shops display special logos and often provide discounts of up to 80 percent off regular prices.
