January weather forecast and climate
Phuket, Thailand

January, like December, is another hot winter month in Phuket, Thailand, with temperature in the range of an average high of 32.7°C (90.9°F) and an average low of 24.5°C (76.1°F).
The perfect water temperature of 28°C (82.4°F) with 30.3mm (1.19") of accumulated rainfall and only 4 rainfall days, makes January a great period for swimming and other water activities.

Temperature

In Phuket, the average high-temperature is relatively the same as in December - a still tropical 32.7°C (90.9°F). The average low-temperature, in January, is 24.5°C (76.1°F).

Heat index

The average heat index in January is estimated at an extremely hot 42.5°C (108.5°F). Be wary - heat exhaustion and heat cramps are highly anticipated. With continued activity, heatstroke is very likely.
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 'felt air temperature', 'feels like', 'real feel', or 'apparent temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Additional factors like metabolic differences, pregnancy, differences in body mass, height, and shape, 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 cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. 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. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

The average relative humidity in Phuket is 70%.

Rainfall

In January, in Phuket, the rain falls for 4 days. Throughout January, 30.3mm (1.19") of precipitation is accumulated. In Phuket, during the entire year, the rain falls for 170 days and collects up to 2219.5mm (87.38") of precipitation.

Sea temperature

Months with the coldest seawater in Phuket are January, February and December, with an average sea temperature of 28°C (82.4°F).
Note: Water temperature between 25°C (77°F) and 29°C (84.2°F) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

Daylight

January and December, with an average of 11.7h of daylight, are months with the shortest days in Phuket.

Sunshine

In January, the average sunshine in Phuket is 9.2h.

UV index

In January, the average daily maximum UV index in Phuket is 11. A UV Index estimate of 11, and higher, represents an extreme health hazard from unprotected exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 11 in January transform into the following instructions:
Practice all-important precautions. Light skin people may get burned in less than 5 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. 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. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.