September weather forecastRiver, IN
September
Weather in September
September, the first month of the autumn in River, is also a moderately hot month, with an average temperature fluctuating between 55.6°F (13.1°C) and 73.9°F (23.3°C).Temperature
September's arrival signals a moderate reduction in the average high-temperature, easing from 79.3°F (26.3°C) in August to a still moderately hot 73.9°F (23.3°C). River usually reports an average low-temperature of 55.6°F (13.1°C) during the month of September.Humidity
In September, the average relative humidity in River, Indiana, is 79%.Rainfall
In River, during September, the rain falls for 13.5 days and regularly aggregates up to 1.57" (40mm) of precipitation. Throughout the year, in River, there are 153.8 rainfall days, and 25" (635mm) of precipitation is accumulated.Snowfall
In River, snow does not fall in May through September.Daylight
In River, Indiana, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 7:09 am and sunset at 8:13 pm. On the last day of the month, sunrise is at 7:38 am and sunset at 7:25 pm EDT.
Sunshine
In September, the average sunshine is 8h.UV index
In River, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: An average maximum UV index of 4 in September leads to these recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
River, IN
- Average high temperature in September: 73.9°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (30.7°F).
- Average low temperature in September: 55.6°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).
Average pressure in September
River, IN
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
River, IN
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity in September
River, IN
- Average humidity in September: 79%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
River, IN
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is April (3.07").
The driest month (with the least rainfall) is February (1.42").
Average rainfall days in September
River, IN
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is January (6.8 days).
Average snowfall in September
River, IN
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.27").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
River, IN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
River, IN
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 18min).
Average sunshine days in September
River, IN
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is October (16 days).
The months with the least sunshine days are February and May (10.5 days).
Average UV index in September
River, IN
- Average UV index in September: 4
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
River, IN
- Average cloud cover in September: 36
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
River, IN
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, September, October, November and December (6mi).
The months with the lowest visibility are January and August (5mi).
