September weather forecastNorthfield, IA
September
Weather in September
The first month of the autumn, September, is still a warm month in Northfield, Iowa, with temperature in the range of an average low of 56.7°F (13.7°C) and an average high of 76.1°F (24.5°C).Temperature
As August transitions into September, Northfield sees a gentle drop in the average high-temperature, transitioning from a warm 81.7°F (27.6°C) to a still moderately hot 76.1°F (24.5°C). In the month of September, an average of 56.7°F (13.7°C) marks the low-temperature.Humidity
In Northfield, the average relative humidity in September is 75%.Rainfall
In September, the rain falls for 10.1 days. Throughout September, 2.01" (51mm) of precipitation is accumulated. Throughout the year, there are 130.4 rainfall days, and 21.81" (554mm) of precipitation is accumulated.Snowfall
In Northfield, snow does not fall in May through September.Daylight
In Northfield, Iowa, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:31 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:47 pm CDT.
Sunshine
In Northfield, the average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Make use of precautions - It is urged to ward off sun damage. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Northfield, IA
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in September: 56.7°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in September
Northfield, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Northfield, IA
- Average wind speed in September: 7.9mph
The windiest months (with the highest average wind speed) are January, February, March and April (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Northfield, IA
- Average humidity in September: 75%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Northfield, IA
- Average rainfall in September: 2.01"
The wettest month (with the highest rainfall) is May (3.23").
The driest month (with the least rainfall) is December (0.87").
Average rainfall days in September
Northfield, IA
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is January (4.7 days).
Average snowfall in September
Northfield, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.03").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Northfield, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Northfield, 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 6min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Northfield, IA
- Average sunshine days in September: 17.9 days
The months with the most sunshine days are October and December (18.5 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in September
Northfield, IA
- 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 January (UV index 1).
Average cloud cover in September
Northfield, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Northfield, 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).





