September weather forecast
Greenhorn, CO

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Weather in September

The first month of the autumn, September, is still a warm month in Greenhorn, Colorado, with an average temperature ranging between min 55.6°F (13.1°C) and max 77.5°F (25.3°C).

Temperature

The transition to September results in a modest reduction in average high-temperature, moving from a warm 84.6°F (29.2°C) in August to a still moderately hot 77.5°F (25.3°C). Greenhorn's nighttime temperatures in September reflect a stark contrast to the day's highs, falling to an average low of 55.6°F (13.1°C).

Humidity

The average relative humidity in September in Greenhorn is 44%.

Rainfall

In Greenhorn, in September, it is raining for 11.4 days, with typically 1.1" (28mm) of accumulated precipitation. Throughout the year, there are 120.5 rainfall days, and 14.92" (379mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 25min.
On the first day of the month, sunrise is at 6:30 am and sunset at 7:28 pm. On the last day of September, sunrise is at 6:54 am and sunset at 6:43 pm MDT.

Sunshine

In Greenhorn, the average sunshine in September is 11h.

UV index

In Greenhorn, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Updated: Aug 30, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The high-temperature, in September, in Greenhorn, is 77.5°F (25.3°C), while the low-temperature averages to 55.6°F (13.1°C). The average heat index (a.k.a. 'real feel', 'feels like'), which combines relative humidity and air temperature, in August is computed to be 84.2°F (29°C).

What is the average humidity in September?

In Greenhorn, Colorado, the average relative humidity in September is 44%.

How many days does it rain in September?

In September, in Greenhorn, the rain falls for 11.4 days. Throughout September, 1.1" (28mm) of precipitation is accumulated.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

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

How many hours of daylight does Greenhorn have in September?

The average day length in September is 12h and 25min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:30 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:43 pm MDT.

How long on average sun shines in September?

In Greenhorn, the average sunshine duration in September is 11h.

What is the UV index reading in September?

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health threat from unprotected exposure to 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
Greenhorn, CO

Average temperature in September - Greenhorn, CO
  • Average high temperature in September: 77.5°F

The warmest month (with the highest average high temperature) is July (86.2°F).
The month with the lowest average high temperature is December (41.5°F).

  • Average low temperature in September: 55.6°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is December (23°F).

Average pressure in September
Greenhorn, CO

Average pressure in September - Greenhorn, CO
  • Average pressure in September: 30.01"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is April (29.89"Hg).

Average wind speed in September
Greenhorn, CO

Average wind speed in September - Greenhorn, CO
  • Average wind speed in September: 6.8mph

The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in September
Greenhorn, CO

Average humidity in September - Greenhorn, CO
  • Average humidity in September: 44%

The month with the highest relative humidity is February (62%).
The month with the lowest relative humidity is June (38%).

Average rainfall in September
Greenhorn, CO

Average rainfall in September - Greenhorn, CO
  • Average rainfall in September: 1.1"

The wettest month (with the highest rainfall) is July (2.76").
The driest month (with the least rainfall) is November (0.43").

Average rainfall days in September
Greenhorn, CO

Average rainfall days in September - Greenhorn, CO
  • Average rainfall days in September: 11.4 days

The month with the highest number of rainy days is July (20.4 days).
The month with the least rainy days is November (3.9 days).

Average snowfall in September
Greenhorn, CO

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

The month with the highest snowfall is February (6.06").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Greenhorn, CO

Average snowfall days in September - Greenhorn, CO
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (7.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

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

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in September: 11h and 0min

The month with the most sunshine is June (Average sunshine: 12h and 0min).
The month with the least sunshine is February (Average sunshine: 6h and 48min).

Average sunshine days in September
Greenhorn, CO

Average sunshine days in September - Greenhorn, CO
  • Average sunshine days in September: 13 days

The month with the most sunshine days is November (23.8 days).
The month with the least sunshine days is July (5.1 days).

Average UV index in September
Greenhorn, CO

Average UV index in September - Greenhorn, 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
Greenhorn, CO

Average cloud cover in September - Greenhorn, CO
  • Average cloud cover in September: 14

The months with the most cloud cover are February and April (Cloud cover 23).
The months with the least cloud cover are June and September (Cloud cover 14).

Average visibility in September
Greenhorn, CO

Average visibility in September - Greenhorn, 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).

Greenhorn, Colorado, USA

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