September weather forecastCommerce City, CO
September
Weather in September
September serves as a transition period, moving from the heat of summer to the cooler fall season. Average temperatures start to decline, dropping to a more comfortable 79.5°F (26.4°C). Skies remain mostly clear, setting a beautiful prelude to the fall. Although September is cooler than August, it is warmer than October. Gently, September weather lets go of the heat of summer.Temperature
The beginning of September brings a minor change in the average high-temperature, shifting from a hot 87.1°F (30.6°C) in August to a warm 79.5°F (26.4°C). September nights indicate a noticeable temperature drop from the daytime highs, with an average reading lowering to a cool 53.8°F (12.1°C).Humidity
The average relative humidity in September in Commerce City is 41%.Rainfall
In Commerce City, in September, it is raining for 3.3 days, with typically 0.16" (4mm) of accumulated precipitation. Throughout the year, there are 48.3 rainfall days, and 3.19" (81mm) of precipitation is accumulated.Snowfall
In Commerce City, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:30 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:43 pm MDT.
Sunshine
The average sunshine in September is 11.1h.UV index
In Commerce City, Colorado, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Experience reduced UV exposure by about half when donning a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Commerce City, CO
- Average high temperature in September: 79.5°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (41.2°F).
- Average low temperature in September: 53.8°F
The month with the highest average low temperature is July (61.7°F).
The coldest month (with the lowest average low temperature) is December (21.9°F).
Average pressure in September
Commerce City, CO
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are April and June (29.91"Hg).
Average wind speed in September
Commerce City, CO
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is April (6.9mph).
The calmest month (with the lowest average wind speed) is December (5.8mph).
Average humidity in September
Commerce City, CO
- Average humidity in September: 41%
The month with the highest relative humidity is February (64%).
The month with the lowest relative humidity is August (39%).
Average rainfall in September
Commerce City, CO
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is July (0.59").
The driest months (with the least rainfall) are January and December (0.08").
Average rainfall days in September
Commerce City, CO
- Average rainfall days in September: 3.3 days
The month with the highest number of rainy days is July (8.2 days).
The month with the least rainy days is February (1.2 days).
Average snowfall in September
Commerce City, CO
- Average snowfall in September: 0"
The month with the highest snowfall is October (1.42").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Commerce City, CO
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Commerce City, CO
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 11h and 6min
The months with the most sunshine are June and July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 42min).
Average sunshine days in September
Commerce City, CO
- Average sunshine days in September: 24.5 days
The month with the most sunshine days is December (28.5 days).
The month with the least sunshine days is July (19.6 days).
Average UV index in September
Commerce City, 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
Commerce City, CO
- Average cloud cover in September: 14
The months with the most cloud cover are February, April and May (Cloud cover 25).
The month with the least cloud cover is September (Cloud cover 14).
Average visibility in September
Commerce City, 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).
