September weather forecastArapahoe, CO
September
Weather in September
September, the first month of the autumn in Arapahoe, is still a warm month, with an average temperature varying between 80.1°F (26.7°C) and 58.3°F (14.6°C).Temperature
The onset of September is marked by a minor decrease in temperature, transitioning from a tropical 87.1°F (30.6°C) in August to a moderately hot 80.1°F (26.7°C). Arapahoe encounters a substantial decline from its daily high to a low-temperature of 58.3°F (14.6°C) during September nights.Humidity
In September, the average relative humidity is 49%.Rainfall
In Arapahoe, Colorado, during September, the rain falls for 10.5 days and regularly aggregates up to 1.1" (28mm) of precipitation. Throughout the year, there are 108.3 rainfall days, and 13.39" (340mm) of precipitation is accumulated.Snowfall
In Arapahoe, snow does not fall in June through September.Daylight
In September, the average length of the day in Arapahoe is 12h and 26min.On the first day of September, sunrise is at 6:18 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:32 pm MDT.
Sunshine
In September, the average sunshine is 10.1h.UV index
In Arapahoe, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: A daily high UV index of 5 in September leads to these guidelines:
Guard yourself - Precautionary measures against sun damage are advocated. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Arapahoe, CO
- Average high temperature in September: 80.1°F
The warmest month (with the highest average high temperature) is July (90°F).
The month with the lowest average high temperature is December (41.2°F).
- Average low temperature in September: 58.3°F
The month with the highest average low temperature is July (67.8°F).
The coldest month (with the lowest average low temperature) is December (24.1°F).
Average pressure in September
Arapahoe, CO
- Average pressure in September: 29.92"Hg
The months with the highest atmospheric pressure are January and December (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.8"Hg).
Average wind speed in September
Arapahoe, CO
- Average wind speed in September: 11.2mph
The windiest month (with the highest average wind speed) is April (13mph).
The calmest month (with the lowest average wind speed) is August (10.3mph).
Average humidity in September
Arapahoe, CO
- Average humidity in September: 49%
The months with the highest relative humidity are January, February and December (61%).
The months with the lowest relative humidity are June and July (48%).
Average rainfall in September
Arapahoe, CO
- Average rainfall in September: 1.1"
The wettest months (with the highest rainfall) are May and July (1.93").
The driest month (with the least rainfall) is January (0.39").
Average rainfall days in September
Arapahoe, CO
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is July (15 days).
The months with the least rainy days are February and December (3.8 days).
Average snowfall in September
Arapahoe, CO
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.28").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Arapahoe, CO
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (7.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Arapahoe, CO
- Average daylight in September: 12h and 24min
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 30min).
- Average sunshine in September: 10h and 6min
The month with the most sunshine is August (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 24min).
Average sunshine days in September
Arapahoe, CO
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is November (22.8 days).
The month with the least sunshine days is July (11.9 days).
Average UV index in September
Arapahoe, CO
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Arapahoe, CO
- Average cloud cover in September: 17
The month with the most cloud cover is February (Cloud cover 30).
The month with the least cloud cover is September (Cloud cover 17).
Average visibility in September
Arapahoe, 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).
