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 arrival of September correlates with a minor temperature reduction, down from August's 79.2°F (26.2°C) to a still moderately hot 73.8°F (23.2°C). Throughout September, Decatur witnesses a nighttime temperature average of 55.8°F (13.2°C).Humidity
The average relative humidity in September is 79%.Rainfall
In Decatur, during September, the rain falls for 13.5 days and regularly aggregates up to 1.57" (40mm) of precipitation. In Decatur, during the entire year, the rain falls for 159.4 days and collects up to 23.74" (603mm) of precipitation.Snowfall
In Decatur, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 27min.On the first day of the month, sunrise is at 7:07 am and sunset at 8:11 pm. On the last day of September, in Decatur, sunrise is at 7:36 am and sunset at 7:22 pm EDT.
Sunshine
In Decatur, the average sunshine in September is 8h.UV index
In Decatur, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 4 suggests this advice:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. To protect against the Sun's most potent rays, avoid direct exposure around midday. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Frequently asked questions
What is the usual temperature for Decatur in September?
What is the average humidity in September in Decatur?
How much does it rain in Decatur in September?
When it does not snow in Decatur?
Does it snow in Decatur in September?
What is the average length of the day in September in Decatur?
When is the sunrise / sunset in September in Decatur?
How long on average sun shines in September in Decatur?
What is the UV index reading in September in Decatur?
Average temperature in September
Decatur, IN
- Average high temperature in September: 73.8°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (31.3°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in September
Decatur, IN
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Decatur, IN
- Average wind speed in September: 6.8mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in September
Decatur, IN
- Average humidity in September: 79%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Decatur, IN
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is May (3.03").
The driest month (with the least rainfall) is February (1.34").
Average rainfall days in September
Decatur, 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 February (7.5 days).
Average snowfall in September
Decatur, IN
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.83").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Decatur, IN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Decatur, IN
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
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 18min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Decatur, IN
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is June (10 days).
Average UV index in September
Decatur, IN
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Decatur, IN
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 64).
The months with the least cloud cover are July and August (Cloud cover 32).
Average visibility in September
Decatur, 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).
Decatur, Indiana, USA
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