September weather forecastThornton, IA
September
Weather in September
September, the first month of the autumn in Thornton, is still a pleasant month, with an average temperature ranging between max 72.7°F (22.6°C) and min 54.3°F (12.4°C).Temperature
During September, Thornton records an average high-temperature of a pleasant 72.7°F (22.6°C), marking a slight divergence from August's 77.9°F (25.5°C). Thornton's temperature drops to an average low of 54.3°F (12.4°C) during the nights of September.Humidity
The average relative humidity in September is 77%.Rainfall
In Thornton, in September, it is raining for 11.8 days, with typically 2.36" (60mm) of accumulated precipitation. Throughout the year, there are 136.3 rainfall days, and 26.18" (665mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 29min.On the first day of September, sunrise is at 6:38 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:55 pm CDT.
Sunshine
In Thornton, the average sunshine in September is 9.1h.UV index
In Thornton, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: The UV index of 4 during September translates into the following guidance:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Thornton, IA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (23.4°F).
- Average low temperature in September: 54.3°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).
Average pressure in September
Thornton, IA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Thornton, IA
- Average wind speed in September: 8.6mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).
Average humidity in September
Thornton, IA
- Average humidity in September: 77%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Thornton, IA
- Average rainfall in September: 2.36"
The wettest month (with the highest rainfall) is June (3.98").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in September
Thornton, IA
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is June (18.6 days).
The month with the least rainy days is February (2.8 days).
Average snowfall in September
Thornton, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.94").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Thornton, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Thornton, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 6min
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 42min).
Average sunshine days in September
Thornton, IA
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is June (10 days).
Average UV index in September
Thornton, IA
- 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
Thornton, IA
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are August and September (Cloud cover 32).
Average visibility in September
Thornton, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
