Chennai
India
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Chennai, India

A staircase to the front entrance of the Ramakrishna Temple in Chennai, India
A staircase to the front entrance of the Ramakrishna Temple in Chennai, India
The last month of the rainy (monsoon) season, September, is also a hot month in Chennai, India, with average temperature ranging between min 27.3°C (81.1°F) and max 31.6°C (88.9°F).

Temperature

In September, the average high-temperature is relatively the same as in August - a still tropical 31.6°C (88.9°F). The average low-temperature, in Chennai, is 27.3°C (81.1°F).

Heat index

In September, the average heat index is evaluated at a torrid 39.9°C (103.8°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'apparent temperature', 'felt air temperature', or 'feels like', is a measure that combines both air temperature and relative humidity into a single value that indicates how hot the weather feels. Additional factors like metabolic differences, clothing, wind, and activity influence one's weather impression. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. 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.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. 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 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 Chennai is 72%.

Rainfall

In Chennai, in September, during 23.1 rainfall days, 98mm (3.86") of precipitation is typically accumulated. In Chennai, during the entire year, the rain falls for 157.6 days and collects up to 823mm (32.4") of precipitation.

Sea temperature

In September, the average sea temperature in Chennai, India, is 29.3°C (84.7°F).
Note: For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.

Daylight

In Chennai, the average length of the day is 12.2h.

Sunshine

The average sunshine in Chennai is 10.7h.

UV index

In September, the average daily maximum UV index in Chennai is 7. A UV Index value of 6 to 7 symbolizes a high threat to health from the exposure to the Sun's UV rays for ordinary individuals.
Note: In September, the average maximum UV index of 7 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. 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 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. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in September in Chennai?

In September, in Chennai, the average high-temperature is 31.6°C (88.9°F), and the average low-temperature is 27.3°C (81.1°F). The average heat index (a.k.a. 'felt air temperature', 'feels like'), that combines air temperature and relative humidity, in September is calculated to 39.9°C (103.8°F).

What is the average humidity in September in Chennai?

In September, the average relative humidity in Chennai, India, is 72%.

How much does it rain in Chennai in September?

In September, the rain falls for 23.1 days. Throughout September, 98mm (3.86") of precipitation is accumulated.

How warm is the water in September in Chennai?

In Chennai, in September, the average water temperature is 29.3°C (84.7°F). 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.

What is the average length of the day in September in Chennai?

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

How many hours of sunshine does Chennai have in September?

In September, the average sunshine in Chennai is 10.7h.

What is the UV index reading in September in Chennai?

In Chennai, the average daily maximum UV index in September is 7. A UV Index of 6 to 7 symbolizes a high health threat from the exposure to the Sun's UV rays.
Average temperature in September - Chennai, India
  • Average high temperature in September: 31.6°C

The warmest month (with the highest average high temperature) is May (34.8°C).
The month with the lowest average high temperature is January (27.3°C).

  • Average low temperature in September: 27.3°C

The month with the highest average low temperature is May (29.6°C).
The coldest month (with the lowest average low temperature) is January (23.4°C).

Average humidity in September - Chennai, India
  • Average humidity in September: 72%

The month with the highest relative humidity is November (76%).
The month with the lowest relative humidity is June (63%).

Average rainfall in September - Chennai, India
  • Average rainfall in September: 98mm

The wettest month (with the highest rainfall) is November (213mm).
The driest month (with the lowest rainfall) is February (6mm).

Average rainfall days in September - Chennai, India
  • Average rainfall days in September: 23.1 days

The month with the highest number of rainy days is September (23.1 days).
The month with the lowest number of rainy days is February (2.9 days).

Average sea temperature in September - Chennai, India
  • Average sea temperature in September: 29.3°C

The best month for swimming (with the highest average sea temperature) is May (29.5°C).
The coldest month (with the lowest average sea temperature) is January (26.8°C).

Average daylight in September / Average sunshine in September - Chennai, India
  • Average daylight in September: 12.2h

The month with the longest days is June (Average daylight: 12.9h).
The month with shortest days is December (Average daylight: 11.4h).

  • Average sunshine in September: 10.7h

The month with most sunshine is May (Average sunshine: 11.9h).
Months with least sunshine are November and December (Average sunshine: 6.3).

Average UV index in September - Chennai, India
  • Average UV index in September: 7

Months with the highest UV index are April, May, June and July (UV index 8).
The month with the lowest UV index is October (UV index 6).