September weather forecast
Thailand

As Thailand enters September, the monsoon season shows initial signs of tapering off, especially towards the month's end. While rain remains frequent, the intensity and duration of downpours start to lessen in several regions, hinting at the upcoming transition to drier months.

In Northern Thailand, adjoining Myanmar and Laos, the rain persists but becomes somewhat sporadic. Prolonged showers are less common, and periods of sunshine begin to punctuate the cloudy days. The temperature spectrum remains comfortable, spanning from 25°C (77°F) to 30°C (86°F), with the decreased rain not yet allowing significant climbs in the thermometer readings.

Bangkok, along with its neighboring territories, witnesses a reduction in rain frequency as September progresses. However, the city still sees regular showers, particularly during the afternoon and evening. Temperature variations in the capital city hover between 27°C (80.6°F) to 31°C (87.8°F). The blend of urban infrastructure and lingering humidity can occasionally create a slightly muggy atmosphere during the non-rainy intervals.

The western coast, including destinations like Phuket and Krabi, continues to experience regular rainfall in September, albeit with less vigor than the preceding months. With the southwest monsoon gradually receding, the instances of storms and rough seas diminish. Travelers, however, should remain alert to sudden changes in weather, as September can still usher in unexpected downpours.

Contrasting with August, September offers a breather as the monsoon slowly loses its grip on Thailand. Rainfall, although frequent, becomes more manageable, and prolonged sunny spells start to reappear, particularly in the latter half of the month. This transition paints a picture of what to expect as Thailand approaches October, a month typically characterized by further reductions in rain and the onset of cooler, pleasant days.

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• Bangkok - September »
  The most humid month in Bangkok, Thailand, is September, with an average relative humidity of 79%. During the month of September, the temperature in Bangkok generally drops to a low average of 25°C (77°F).
• Chiang Mai - September »
  August and September, with an average relative humidity of 81%, are most humid months in Chiang Mai, Thailand. August and September, with an average of 5.2h of sunshine, are months with the least sunshine in Chiang Mai, Thailand.
• Pattaya - September »
  February through September, with an average maximum UV index of 12, are months with the highest UV index in Pattaya, Thailand. The months with the highest UV index in Pattaya are February through September, with an average maximum UV index of 12.
• Phuket - September »
  September and October, with an average relative humidity of 82%, are most humid months in Phuket, Thailand. The yearly lowest temperatures in Phuket, Thailand, occur in September and October, averaging a high-temperature of 31.5°C (88.7°F).
• Nakhon Ratchasima - September »
  The month with the most rainfall in Nakhon Ratchasima, Thailand, is September, when the rain falls for 19 days and typically aggregates up to 228mm (8.98") of precipitation. September is the most humid month in Nakhon Ratchasima, with an average relative humidity of 80%.
• Udon Thani - September »
  August and September, with an average relative humidity of 81%, are the most humid months in Udon Thani. Therefore, the weather in Udon Thani in September can be classified as warm, decreasing rainfall, and high humidity, hinting at the waning monsoons.
• Hua Hin - September »
  In September, the average heat index, which combines relative humidity and air temperature, is computed to be 45°C (113°F). On the first day of September in Hua Hin, Thailand, sunrise is at 06:09 and sunset at 18:30.
• Krabi - September »
  In Krabi, Thailand, in September, it is raining for 22 days, with typically 355mm (13.98") of accumulated precipitation. In September, Krabi experiences the highest rainfall of the year averaging 355mm (13.98").
• Hat Yai - September »
  The average heat index, which calculates the temperature value influenced by the moisture in the air, in September is evaluated at 47°C (116.6°F). In September, Hat Yai experiences a minor retreat in temperatures, providing some relief to the scorching summer heat.
• Surat Thani - September »
  In Surat Thani in September, during 19 rainfall days, 188mm (7.4") of precipitation is typically accumulated. In Surat Thani in September, the average water temperature is 29°C (84.2°F).
• Chiang Rai - September »
  In Chiang Rai during September, the rain falls for 18 days and regularly aggregates up to 284mm (11.18") of precipitation. In Chiang Rai, Thailand, during September, the rain falls for 18 days and regularly aggregates up to 284mm (11.18") of precipitation.
• Khon Kaen - September »
  September is the most humid month in Khon Kaen, Thailand, with an average relative humidity of 83%. In Khon Kaen, Thailand, during September, the rain falls for 18 days and regularly aggregates up to 232mm (9.13") of precipitation.