September weather forecast
Fairfax, IA

Weather in September

September, the first month of the autumn in Fairfax, is still a warm month, with temperature in the range of an average low of 55.2°F (12.9°C) and an average high of 74.3°F (23.5°C).

Temperature

In Fairfax, Iowa, the average high-temperature in September is relatively the same as in August - a still moderately hot 74.3°F (23.5°C). In September, in Fairfax, the average low-temperature is 55.2°F (12.9°C).

Humidity

In September, the average relative humidity in Fairfax is 77%.

Rainfall

In September, in Fairfax, Iowa, the rain falls for 10.9 days. Throughout September, 1.73" (44mm) of precipitation is accumulated. Throughout the year, in Fairfax, there are 120.7 rainfall days, and 18.31" (465mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall in Fairfax.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:33 am and sunset at 7:41 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:50 pm CDT.

Sunshine

The average sunshine in September is 9.3h.

UV index

In Fairfax, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for average individuals.
Note: The average daily UV index of 4 in September transform into the following instructions:
Take precautions - Protection against skin and eye damage is obliged. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the average humidity in September in Fairfax?

In Fairfax, the average relative humidity in September is 77%.

How much does it rain in Fairfax in September?

In Fairfax, in September, it is raining for 10.9 days, with typically 1.73" (44mm) of accumulated precipitation.

When it does not snow in Fairfax?

In Fairfax, snow does not fall in May through September.

Does it snow in Fairfax in September?

In Fairfax, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Fairfax have in September?

The average day length in September in Fairfax is 12h and 28min.

When is the sunrise / sunset in September in Fairfax?

On the first day of September in Fairfax, Iowa, sunrise is at 6:33 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:50 pm CDT.

How long on average sun shines in September in Fairfax?

In September, the average sunshine duration in Fairfax is 9.3h.

What is the UV index reading in September in Fairfax?

In Fairfax, Iowa, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Fairfax, IA

Average temperature in September - Fairfax, IA
  • Average high temperature in September: 74.3°F

The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (26.2°F).

  • Average low temperature in September: 55.2°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (14.2°F).

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Average pressure in September
Fairfax, IA

Average pressure in September - Fairfax, 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).

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Average wind speed in September
Fairfax, IA

Average wind speed in September - Fairfax, IA
  • Average wind speed in September: 8mph

The windiest months (with the highest average wind speed) are January and April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).

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Average humidity in September
Fairfax, IA

Average humidity in September - Fairfax, IA
  • Average humidity in September: 77%

The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (73%).

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Average rainfall in September
Fairfax, IA

Average rainfall in September - Fairfax, IA
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is May (3.07").
The driest months (with the least rainfall) are January and February (0.63").

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Average rainfall days in September
Fairfax, IA

Average rainfall days in September - Fairfax, IA
  • Average rainfall days in September: 10.9 days

The month with the highest number of rainy days is May (16 days).
The month with the least rainy days is February (3 days).

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Average snowfall in September
Fairfax, IA

Average snowfall in September - Fairfax, IA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.64").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Fairfax, IA

Average snowfall days in September - Fairfax, IA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Fairfax, IA

Average daylight in September / Average sunshine in September - Fairfax, IA
  • Average daylight in September: 12h and 28min

The month with the longest days is June (Average daylight: 15h and 11min).
The month with the shortest days is December (Average daylight: 9h and 11min).

  • Average sunshine in September: 9h and 18min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

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Average sunshine days in September
Fairfax, IA

Average sunshine days in September - Fairfax, IA
  • Average sunshine days in September: 18.2 days

The month with the most sunshine days is October (19.9 days).
The month with the least sunshine days is June (11.8 days).

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Average UV index in September
Fairfax, IA

Average UV index in September - Fairfax, 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 and December (UV index 1).

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Average cloud cover in September
Fairfax, IA

Average cloud cover in September - Fairfax, IA
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are August and September (Cloud cover 30).

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Average visibility in September
Fairfax, IA

Average visibility in September - Fairfax, 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).

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