Chiang Rai
Thailand
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Chiang Rai, Thailand

The White Temple of Wat Rong Khun with a waterfront fishpond in Chiang Rai, Thailand, on a beautiful cloudy day panorama
The White Temple of Wat Rong Khun with a waterfront fishpond in Chiang Rai, Thailand, on a beautiful cloudy day panorama
The first month of the autumn, September, is still a tropical month in Chiang Rai, Thailand, with average temperature varying between 31.1°C (88°F) and 22.7°C (72.9°F).

Temperature

In Chiang Rai, the average high-temperature is practically the same as in August - a still tropical 31.1°C (88°F). The average low-temperature, in Chiang Rai, is 22.7°C (72.9°F).

Heat index

In September, the average heat index is calculated to a scorching 42.3°C (108.1°F). Beware - heat cramps and heat exhaustion are very likely. Heatstroke is imminent with prolonged activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'apparent temperature', 'felt air temperature', or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Additional factors like clothing, pregnancy, wind, and activity influence one's weather impression. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. If the body can not disperse the excessive heat and body temperature reaches conditions of hyperthermia, above 37.5°C (99.5°F) to 38.3°C (100.9°F), thermal conditions are potentially life-threatening.

Humidity

In September, the average relative humidity is 83%.

Rainfall

In September, the rain falls for 18 days. Throughout September, 283.9mm (11.2") of precipitation is accumulated. Throughout the year, there are 137 rainfall days, and 1690.5mm (66.6") of precipitation is accumulated.

Daylight

In September, the average length of the day is 12.3h.

Sunshine

The average sunshine in September is 6h.

UV index

March through September, with an average maximum UV index of 12, are months with the highest UV index. A UV Index reading of 11, and higher, represents an excessive health risk from the exposure to the Sun's UV rays for the ordinary person.
Note: In September, the average maximum UV index of 12 translate into the following recommendations:
Take all required precautions, as unprotected skin and eyes can burn in minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise.

What is the temperature in September in Chiang Rai?

In Chiang Rai, Thailand, in September, the average high-temperature is 31.1°C (88°F), and the average low-temperature is 22.7°C (72.9°F). In September, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), that calculates temperature value influenced by the moisture in the air, is appraised at 42.3°C (108.1°F).

What is the average humidity in September in Chiang Rai?

The average relative humidity in September in Chiang Rai is 83%.

How many days does it rain in September in Chiang Rai?

In Chiang Rai, Thailand, during September, the rain falls for 18 days and regularly aggregates up to 283.9mm (11.2") of precipitation.

What is the average length of the day in September in Chiang Rai?

The average length of the day in September is 12.3h.

How long on average sun shines in September in Chiang Rai?

In Chiang Rai, Thailand, the average sunshine in September is 6h.

What are the months with the highest UV index in Chiang Rai?

March through September, with an average maximum UV index of 12, are months with the highest UV index in Chiang Rai, Thailand.

What is the UV index intensity in September in Chiang Rai?

In Chiang Rai, the average daily maximum UV index in September is 12. A UV Index of 11, and more, symbolizes an ultimate hazard to health from the exposure to the Sun's UV radiation.
Average temperature in September - Chiang Rai, Thailand
  • Average high temperature in September: 31.1°C

The warmest month (with the highest average high temperature) is April (34.8°C).
The month with the lowest average high temperature is December (27.2°C).

  • Average low temperature in September: 22.7°C

The month with the highest average low temperature is June (23.6°C).
The coldest month (with the lowest average low temperature) is January (12.8°C).

Average humidity in September - Chiang Rai, Thailand
  • Average humidity in September: 83%

The month with the highest relative humidity is August (84%).
The month with the lowest relative humidity is March (62%).

Average rainfall in September - Chiang Rai, Thailand
  • Average rainfall in September: 283.9mm

The wettest month (with the highest rainfall) is August (358.4mm).
The driest month (with the lowest rainfall) is January (7.5mm).

Average rainfall days in September - Chiang Rai, Thailand
  • Average rainfall days in September: 18 days

The month with the highest number of rainy days is August (24 days).
The month with the lowest number of rainy days is February (1 days).

Average daylight in September / Average sunshine in September - Chiang Rai, Thailand
  • Average daylight in September: 12.3h

The month with the longest days is June (Average daylight: 13.3h).
The month with shortest days is December (Average daylight: 10.9h).

  • Average sunshine in September: 6h

The month with most sunshine is February (Average sunshine: 9h).
Months with least sunshine are June, July and August (Average sunshine: 5).

Average UV index in September - Chiang Rai, Thailand
  • Average UV index in September: 12

Months with the highest UV index are March, April, May, June, July, August and September (UV index 12).
The month with the lowest UV index is December (UV index 7).