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
September brings a slight decrease in temperature, down from 85.1°F (29.5°C) in August to a still warm 76.3°F (24.6°C). In September, Fairfax experiences a temperature dip to an average of 55.4°F (13°C) at night.Humidity
In Fairfax, the average relative humidity in September is 63%.Rainfall
In Fairfax, in September, it is raining for 9.4 days, with typically 1.02" (26mm) of accumulated precipitation. In Fairfax, during the entire year, the rain falls for 104.1 days and collects up to 14.29" (363mm) of precipitation.Snowfall
May through September are months without snowfall in Fairfax.Daylight
In Fairfax, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 7:00 am and sunset at 8:09 pm. On the last day of September, sunrise is at 7:32 am and sunset at 7:17 pm CDT.
Sunshine
The average sunshine in September in Fairfax is 8.9h.UV index
The average daily maximum UV index in September in Fairfax is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: In September, the UV index of 5 transforms into the following advice:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The solar radiation around mid-day is intense; avoid the Sun and stay safe. 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
What is the usual temperature for Fairfax in September?
What is the average humidity in September in Fairfax?
How many days does it rain in September in Fairfax?
When it does not snow in Fairfax?
Does it snow in Fairfax in September?
How many hours of daylight does Fairfax have in September?
When is the sunrise / sunset in September in Fairfax?
How many hours of sunshine does Fairfax have in September?
What is the UV index intensity in September in Fairfax?
Average temperature in September
Fairfax, SD
- Average high temperature in September: 76.3°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (27.3°F).
- Average low temperature in September: 55.4°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (13.6°F).
Average pressure in September
Fairfax, SD
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Fairfax, SD
- Average wind speed in September: 9.4mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (8.3mph).
Average humidity in September
Fairfax, SD
- Average humidity in September: 63%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (62%).
Average rainfall in September
Fairfax, SD
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is May (2.72").
The driest month (with the least rainfall) is February (0.31").
Average rainfall days in September
Fairfax, SD
- Average rainfall days in September: 9.4 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (2.9 days).
Average snowfall in September
Fairfax, SD
- Average snowfall in September: 0"
The months with the highest snowfall are January and March (1.93").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Fairfax, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.2 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
Fairfax, SD
- Average daylight in September: 12h and 3min
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: 8h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in September
Fairfax, SD
- Average sunshine days in September: 18.4 days
The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is June (12.3 days).
Average UV index in September
Fairfax, SD
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Fairfax, SD
- Average cloud cover in September: 24
The month with the most cloud cover is January (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 23).
Average visibility in September
Fairfax, SD
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Fairfax, South Dakota, USA
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