September weather forecastWhittier, IA
September
Weather in September
The first month of the autumn, September, is still a warm month in Whittier, Iowa, with an average temperature fluctuating between 54.7°F (12.6°C) and 73.4°F (23°C).Temperature
The transition to September results in a modest reduction in average high-temperature, moving from 79.3°F (26.3°C) in August to a still warm 73.4°F (23°C). An average low-temperature of 54.7°F (12.6°C) is recorded in the month of September in Whittier.Humidity
In September, the average relative humidity in Whittier is 78%.Rainfall
In Whittier, in September, during 11.4 rainfall days, 2.52" (64mm) of precipitation is typically accumulated. In Whittier, during the entire year, the rain falls for 137.5 days and collects up to 27.68" (703mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In Whittier, the average length of the day in September is 12h and 28min.On the first day of September in Whittier, sunrise is at 6:32 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:48 pm CDT.
Sunshine
In Whittier, the average sunshine in September is 9.2h.UV index
In Whittier, Iowa, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Act with care - The need to guard against sun damage is communicated. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Whittier, IA
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (25.5°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure in September
Whittier, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Whittier, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in September
Whittier, IA
- Average humidity in September: 78%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Whittier, IA
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.45").
The driest month (with the least rainfall) is February (1.02").
Average rainfall days in September
Whittier, IA
- Average rainfall days in September: 11.4 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Whittier, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.16").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Whittier, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Whittier, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 12min
The months with the most sunshine are July and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Whittier, IA
- Average sunshine days in September: 17.4 days
The month with the most sunshine days is December (18.2 days).
The month with the least sunshine days is May (10.9 days).
Average UV index in September
Whittier, IA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Whittier, IA
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Whittier, 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).
