September weather forecastOllie, IA
September
Weather in September
September, the first month of the autumn in Ollie, is also a moderately hot month, with temperature in the range of an average low of 56.3°F (13.5°C) and an average high of 75.2°F (24°C).Temperature
September is characterized by a mild reduction in the average high-temperature, from a moderately hot 81.1°F (27.3°C) in August to a still warm 75.2°F (24°C). An average low-temperature of 56.3°F (13.5°C) is noted during the nights in September.Humidity
In September, the average relative humidity in Ollie is 76%.Rainfall
In September, the rain falls for 12.1 days. Throughout September, 2.76" (70mm) of precipitation is accumulated. In Ollie, during the entire year, the rain falls for 137.9 days and collects up to 27.76" (705mm) of precipitation.Snowfall
In Ollie, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:35 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:51 pm CDT.
Sunshine
In Ollie, the average sunshine in September is 9.4h.UV index
In Ollie, Iowa, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Heed the precautions - Suggestions to avoid sunburn are made. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Ollie, IA
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (28.6°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (15.6°F).
Average pressure in September
Ollie, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Ollie, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).
Average humidity in September
Ollie, IA
- 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
Ollie, IA
- Average rainfall in September: 2.76"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in September
Ollie, IA
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in September
Ollie, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.06").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Ollie, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Ollie, IA
- Average daylight in September: 12h and 30min
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: 9h and 24min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Ollie, IA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is December (19.1 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Ollie, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (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
Ollie, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility in September
Ollie, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).





