September weather forecast
Iliff, CO

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Iliff, Colorado, with temperature in the range of an average high of 78.8°F (26°C) and an average low of 56.3°F (13.5°C).

Temperature

The transition into September is accompanied by a slight temperature decrease, with the average high-temperature shifting from a hot 86.2°F (30.1°C) in August to a warm 78.8°F (26°C). During September, Iliff reports a marked contrast from daily peak temperatures, with an average nighttime reading of 56.3°F (13.5°C).

Humidity

September is the least humid month, with an average relative humidity of 47%.

Rainfall

In Iliff, in September, during 10.1 rainfall days, 0.98" (25mm) of precipitation is typically accumulated. Throughout the year, there are 123.2 rainfall days, and 15.39" (391mm) of precipitation is accumulated.

Snowfall

In Iliff, Colorado, snow does not fall in June through September.

Daylight

In Iliff, Colorado, the average length of the day in September is 12h and 27min.
On the first day of the month, sunrise is at 6:20 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:35 pm MDT.

Sunshine

The average sunshine in September is 10.3h.

UV index

The average daily maximum UV index in September in Iliff is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Iliff in September?

The high-temperature in Iliff during September is 78.8°F (26°C) and the low-temperature is 56.3°F (13.5°C). In August, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which factors the actual air temperature with the relative humidity, is calculated to be 87.8°F (31°C).

What is the least humid month in Iliff?

September is the least humid month, with an average relative humidity of 47%.

What is the average humidity in September in Iliff?

In Iliff, the average relative humidity in September is 47%.

How many days does it rain in September in Iliff?

In Iliff, in September, during 10.1 rainfall days, 0.98" (25mm) of precipitation is typically accumulated.

When it does not snow in Iliff?

In Iliff, Colorado, snow does not fall in June through September.

Does it snow in Iliff in September?

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

How many hours of daylight does Iliff have in September?

In September, the average day length is 12h and 27min.

What time are sunrise and sunset in September in Iliff?

In September, on the first day of the month, sunrise is at 6:20 am and sunset at 7:24 pm. On the last day of the month, in Iliff, Colorado, sunrise is at 6:48 am and sunset at 6:35 pm MDT.

How long on average sun shines in September in Iliff?

In Iliff, Colorado, the average sunshine duration in September is 10.3h.

What is the UV index reading in September in Iliff?

In Iliff, Colorado, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Iliff, CO

Average temperature in September - Iliff, CO
  • Average high temperature in September: 78.8°F

The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is December (37.8°F).

  • Average low temperature in September: 56.3°F

The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is December (23°F).

Average pressure in September
Iliff, CO

Average pressure in September - Iliff, CO
  • Average pressure in September: 29.94"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).

Average wind speed in September
Iliff, CO

Average wind speed in September - Iliff, CO
  • Average wind speed in September: 9.5mph

The windiest month (with the highest average wind speed) is April (11.9mph).
The calmest month (with the lowest average wind speed) is August (9mph).

Average humidity in September
Iliff, CO

Average humidity in September - Iliff, CO
  • Average humidity in September: 47%

The month with the highest relative humidity is January (65%).
The month with the lowest relative humidity is September (47%).

Average rainfall in September
Iliff, CO

Average rainfall in September - Iliff, CO
  • Average rainfall in September: 0.98"

The wettest month (with the highest rainfall) is May (2.95").
The driest month (with the least rainfall) is January (0.35").

Average rainfall days in September
Iliff, CO

Average rainfall days in September - Iliff, CO
  • Average rainfall days in September: 10.1 days

The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is February (4.2 days).

Average snowfall in September
Iliff, CO

Average snowfall in September - Iliff, CO
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.68").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Iliff, CO

Average snowfall days in September - Iliff, CO
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is February (6.7 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Iliff, CO

Average daylight in September / Average sunshine in September - Iliff, CO
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 10h and 2min

The months with the most sunshine are June and August (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 18min).

Average sunshine days in September
Iliff, CO

Average sunshine days in September - Iliff, CO
  • Average sunshine days in September: 16.8 days

The month with the most sunshine days is January (22.3 days).
The month with the least sunshine days is July (9.8 days).

Average UV index in September
Iliff, CO

Average UV index in September - Iliff, CO
  • 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
Iliff, CO

Average cloud cover in September - Iliff, CO
  • Average cloud cover in September: 19

The month with the most cloud cover is February (Cloud cover 33).
The month with the least cloud cover is August (Cloud cover 17).

Average visibility in September
Iliff, CO

Average visibility in September - Iliff, CO
  • 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).

Iliff, Colorado, USA

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