September weather forecast
Phuket, Thailand

September, the first month of the autumn, in Phuket, is also a hot month, with average temperature ranging between max 31.5°C (88.7°F) and min 24.6°C (76.3°F).

Temperature

September and October, with an average high-temperature of 31.5°C (88.7°F), are the coldest months.

Heat index

In September, the average heat index is computed to be an extremely hot 43.4°C (110.1°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 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 'felt air temperature', 'apparent temperature', 'feels like', or 'real feel', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (wind, metabolic differences, pregnancy), and activity. 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. 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.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. When the relative humidity is high, the evaporation rate is reduced. The warmth is removed from the body at a lower rate, causing the body to retain more heat than it would in dry air. 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

September and October, with an average relative humidity of 82%, are most humid months in Phuket.

Rainfall

September is the month with the most rainfall in Phuket, Thailand. Rain falls for 23 days and accumulates 361.2mm (14.22") of precipitation.

Sea temperature

In Phuket, the average seawater temperature in September is 29°C (84.2°F).
Note: For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

In September, the average length of the day in Phuket is 12.2h.

Sunshine

In Phuket, the average sunshine is 4.8h.

UV index

Months with the highest UV index are February through October, with an average maximum UV index of 12. A UV Index estimate of 11, and higher, represents an extreme health hazard from the exposure to the Sun's UV radiation for ordinary individuals.
Note: The daily maximum UV index of 12 interpret into the following advice:
Take all necessary precautions, as unprotected skin can burn in minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.