September weather forecast
Chiang Rai, Thailand

The White Temple of Wat Rong Khun with a waterfront fishpond in Chiang Rai, Thailand
The White Temple of Wat Rong Khun with a waterfront fishpond in Chiang Rai, Thailand

Weather in September

The first month of the autumn, September, is still a hot month in Chiang Rai, Thailand, with an average temperature varying between 22.7°C (72.9°F) and 31.1°C (88°F).

Temperature

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

Heat index

The average heat index in September is estimated at a blistering 42°C (107.6°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'felt air temperature', 'feels like', or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Additional factors like activity, clothing, pregnancy, and metabolic differences affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

In Chiang Rai, the average relative humidity in September is 83%.

Rainfall

In Chiang Rai, it is raining for 18 days, with typically 284mm (11.18") of accumulated precipitation. In Chiang Rai, during the entire year, the rain falls for 137 days and collects up to 1691mm (66.57") of precipitation.

Daylight

In Chiang Rai, the average length of the day in September is 12h and 16min.
On the first day of the month, sunrise is at 06:05 and sunset at 18:36. On the last day of September, in Chiang Rai, Thailand, sunrise is at 06:11 and sunset at 18:10 +07.

Sunshine

In September, the average sunshine is 6h.

UV index

The months with the highest UV index are March through September, with an average maximum UV index of 12. A UV Index estimate of 11, and higher, represents an excessive health risk from exposure to the Sun's UV rays for average individuals.
Note: The daily maximum UV index of 12 in September interpret into the following advice:
Practice all-important precautions. Light skin people may get burned in less than 5 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. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. 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.
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FAQ

What is the temperature in September in Chiang Rai?

The average high-temperature, in September, in Chiang Rai, is 31.1°C (88°F), while the average low-temperature is 22.7°C (72.9°F). in September, the average heat index (a.k.a. 'real feel', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, is estimated at 42°C (107.6°F).

What is the average humidity in September in Chiang Rai?

In September, the average relative humidity is 83%.

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

In September, in Chiang Rai, Thailand, the rain falls for 18 days. Throughout September, 284mm (11.18") of precipitation is accumulated.

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

The average day length in September in Chiang Rai is 12h and 16min.

What time are sunrise and sunset in September in Chiang Rai?

In September, on the first day of the month, sunrise is at 06:05 and sunset at 18:36. On the last day of the month, sunrise is at 06:11 and sunset at 18:10 +07.

How many hours of sunshine does Chiang Rai have in September?

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

When is the highest UV index in Chiang Rai?

The months with the highest UV index are March through September, with an average maximum UV index of 12.

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

The average daily maximum UV index in September in Chiang Rai is 12. A UV Index of 11, and more, symbolizes an ultimate hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average sunshine
Average UV index

Average temperature in September
Chiang Rai, Thailand

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).

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Average humidity in September
Chiang Rai, Thailand

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%).

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Average rainfall in September
Chiang Rai, Thailand

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 least rainfall) is January (7.5mm).

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Average rainfall days in September
Chiang Rai, Thailand

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 least rainy days is February (1 days).

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Average daylight in September /
Average sunshine in September
Chiang Rai, Thailand

Average daylight in September / Average sunshine in September - Chiang Rai, Thailand
  • Average daylight in September: 12h and 16min

The month with the longest days is June (Average daylight: 13h and 19min).
The month with the shortest days is December (Average daylight: 10h and 57min).

  • Average sunshine in September: 6h

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

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Average UV index in September
Chiang Rai, Thailand

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

The 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).

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