September weather forecastVallam, India
September
Weather in September
September, the last month of the rainy (monsoon) season in Vallam, is another hot month, with an average temperature fluctuating between 34.9°C (94.8°F) and 25.8°C (78.4°F).Temperature
As August turns into September, the average high-temperatures rest at a hot 34.9°C (94.8°F), showing a minor variation from the prior month. September nights are marked by an average low-temperature of 25.8°C (78.4°F).Heat index
During September, the heat index is calculated to be a blazing hot 46°C (114.8°F). Be cautious: Heat exhaustion along with heat cramps are predicted. Heatstroke is a possible consequence of continuous physical effort.It is noted that heat index values are ascertained for locations in the shade and with gentle breezes. Heat index values have the potential to be boosted by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. When directly under the sun, the weather's impact can intensify, possibly boosting the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Children regularly disregard the necessity to rest and replenish fluids. Thirst is a late symptom of dehydration - thus, maintaining hydration, particularly during long-lasting physical activities, is essential.
The natural cooling mechanism in humans involves perspiration, where the evaporation of sweat balances out excessive warmth. Under conditions of high temperature and humidity (enhanced heat index), sweat production is compromised, exacerbating the sensation of warmth. Heat-related disorders may develop if heat gain in the body overshadows its cooling capacity, leading to elevated temperatures.
Humidity
The average relative humidity in September is 63%.Rainfall
In Vallam, India, in September, it is raining for 16.5 days, with typically 49mm (1.93") of accumulated precipitation. Throughout the year, there are 145 rainfall days, and 512mm (20.16") of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 11min.On the first day of September, sunrise is at 6:04 am and sunset at 6:23 pm. On the last day of the month, sunrise is at 6:02 am and sunset at 6:04 pm IST.
Sunshine
In Vallam, the average sunshine in September is 8.8h.UV index
In Vallam, the average daily maximum UV index in September is 7. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for the ordinary person.Note: An average UV index of 7 in September transforms into this advice:
Avert overexposure. Light-skinned people might experience burning in less than 20 minutes. Between 10 a.m. and 4 p.m., the Sun's UV radiation is at its peak. Limit your exposure to direct sunlight during these hours. 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.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Vallam, India
- Average high temperature in September: 34.9°C
The warmest month (with the highest average high temperature) is May (38.6°C).
The month with the lowest average high temperature is December (29.1°C).
- Average low temperature in September: 25.8°C
The month with the highest average low temperature is May (28.8°C).
The coldest month (with the lowest average low temperature) is January (20.1°C).
Average pressure in September
Vallam, India
- Average pressure in September: 1007.5mbar
The month with the highest atmospheric pressure is January (1013.3mbar).
The month with the lowest atmospheric pressure is June (1005.6mbar).
Average wind speed in September
Vallam, India
- Average wind speed in September: 11.2km/h
The windiest month (with the highest average wind speed) is June (16km/h).
The calmest month (with the lowest average wind speed) is October (10km/h).
Average humidity in September
Vallam, India
- Average humidity in September: 63%
The month with the highest relative humidity is November (80%).
The month with the lowest relative humidity is June (51%).
Average rainfall in September
Vallam, India
- Average rainfall in September: 49mm
The wettest month (with the highest rainfall) is October (128mm).
The driest month (with the least rainfall) is February (11mm).
Average rainfall days in September
Vallam, India
- Average rainfall days in September: 16.5 days
The month with the highest number of rainy days is October (21.9 days).
The month with the least rainy days is February (5.5 days).
Average daylight in September /
Average sunshine in September
Vallam, India
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 12h and 42min).
The month with the shortest days is December (Average daylight: 11h and 30min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is May (Average sunshine: 11h and 42min).
The month with the least sunshine is November (Average sunshine: 5h and 42min).
Average sunshine days in September
Vallam, India
- Average sunshine days in September: 11.9 days
The month with the most sunshine days is July (24.1 days).
The month with the least sunshine days is October (7.6 days).
Average UV index in September
Vallam, India
- Average UV index in September: 7
The months with the highest UV index are March, April, May, June, July and August (UV index 8).
The months with the lowest UV index are January, October, November and December (UV index 6).
Average cloud cover in September
Vallam, India
- Average cloud cover in September: 35
The month with the most cloud cover is November (Cloud cover 42).
The month with the least cloud cover is March (Cloud cover 17).
Average visibility in September
Vallam, India
- Average visibility in September: 10km
The months with the highest visibility are February, March, April, May, June, July, August, September and October (10km).
The months with the lowest visibility are January, November and December (9km).





