Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September brings an average high-temperature of a still moderately hot 77°F (25°C), nearly matching the August temperature. Riley's average low-temperature is measured at a refreshing 58.6°F (14.8°C) during September.Humidity
In Riley, Indiana, the average relative humidity in September is 76%.Rainfall
In Riley, in September, during 11.1 rainfall days, 1.46" (37mm) of precipitation is typically accumulated. Throughout the year, in Riley, there are 147.1 rainfall days, and 25.87" (657mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Riley.Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 7:18 am and sunset at 8:19 pm. On the last day of September, sunrise is at 7:45 am and sunset at 7:32 pm EDT.
Sunshine
In Riley, the average sunshine in September is 8.5h.UV index
In Riley, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum high UV index of 5 in September translates into the following recommendations:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Frequently asked questions
What is the usual temperature for Riley in September?
What is the average humidity in September in Riley?
How many days does it rain in September in Riley?
When it does not snow in Riley?
What is the average length of the day in September in Riley?
When are sunrise and sunset in September in Riley?
How many hours of sunshine does Riley have in September?
What is the UV index reading in September in Riley?
Average temperature in September
Riley, IN
- Average high temperature in September: 77°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (34.3°F).
- Average low temperature in September: 58.6°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (22.1°F).
Average pressure in September
Riley, IN
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Riley, IN
- Average wind speed in September: 6.6mph
The windiest months (with the highest average wind speed) are January and February (9.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.9mph).
Average humidity in September
Riley, IN
- Average humidity in September: 76%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Riley, IN
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is April (3.62").
The driest month (with the least rainfall) is February (1.42").
Average rainfall days in September
Riley, IN
- Average rainfall days in September: 11.1 days
The month with the highest number of rainy days is May (19 days).
The month with the least rainy days is February (7.8 days).
Average snowfall in September
Riley, IN
- Average snowfall in September: 0"
The month with the highest snowfall is December (1.85").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Riley, IN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Riley, IN
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 3min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in September
Riley, IN
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is November (19 days).
The month with the least sunshine days is May (9.3 days).
Average UV index in September
Riley, IN
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in September
Riley, IN
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are June, August and September (Cloud cover 31).
Average visibility in September
Riley, IN
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Riley, Indiana, USA
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