September weather forecastBoone, CO
September
Weather in September
September, the first month of the autumn in Boone, is also a moderately hot month, with temperature in the range of an average low of 58.5°F (14.7°C) and an average high of 80.1°F (26.7°C).Temperature
September is characterized by a slight reduction in average high-temperature, easing from a tropical 87.4°F (30.8°C) in August to a moderately hot 80.1°F (26.7°C). Marked by a significant temperature drop from daytime highs, the average nighttime temperature lowers to a mild 58.5°F (14.7°C) throughout September.Humidity
The average relative humidity in September is 41%.Rainfall
In September, the rain falls for 7.6 days. Throughout September, 0.55" (14mm) of precipitation is accumulated. Throughout the year, there are 83.6 rainfall days, and 9.29" (236mm) of precipitation is accumulated.Snowfall
In Boone, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 25min.On the first day of September in Boone, Colorado, sunrise is at 6:27 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:52 am and sunset at 6:40 pm MDT.
Sunshine
The average sunshine in September is 10.9h.UV index
The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: A daily maximum UV index of 5 in September translates into the following instructions:
Heed the precautions - Suggestions to avoid sunburn are made. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Boone, CO
- Average high temperature in September: 80.1°F
The warmest month (with the highest average high temperature) is July (89.2°F).
The month with the lowest average high temperature is December (43°F).
- Average low temperature in September: 58.5°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is December (24.4°F).
Average pressure in September
Boone, CO
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is April (29.88"Hg).
Average wind speed in September
Boone, CO
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (9.3mph).
The calmest month (with the lowest average wind speed) is December (7.1mph).
Average humidity in September
Boone, CO
- Average humidity in September: 41%
The month with the highest relative humidity is February (59%).
The month with the lowest relative humidity is June (36%).
Average rainfall in September
Boone, CO
- Average rainfall in September: 0.55"
The wettest month (with the highest rainfall) is July (1.81").
The driest month (with the least rainfall) is December (0.28").
Average rainfall days in September
Boone, CO
- Average rainfall days in September: 7.6 days
The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is November (2.3 days).
Average snowfall in September
Boone, CO
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.23").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Boone, CO
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (6.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Boone, 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 36min).
- Average sunshine in September: 10h and 54min
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 42min).
Average sunshine days in September
Boone, CO
- Average sunshine days in September: 19.5 days
The month with the most sunshine days is December (25.1 days).
The month with the least sunshine days is July (12.3 days).
Average UV index in September
Boone, CO
- Average UV index in September: 5
The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Boone, CO
- Average cloud cover in September: 15
The month with the most cloud cover is February (Cloud cover 24).
The month with the least cloud cover is June (Cloud cover 14).
Average visibility in September
Boone, 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).
