Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
In September, the meteorological conditions change slightly, with the average high-temperature moving from a moderately hot 74.1°F (23.4°C) in August to a comfortable 66.9°F (19.4°C). Basalt witnesses a consistent, sharp contrast from the daytime highs, with an average low-temperature of 37.2°F (2.9°C) throughout September.Humidity
In Basalt, the average relative humidity in September is 54%.Rainfall
The month with the least rainfall is September, when the rain falls for 9.2 days and typically collects 0.63" (16mm) of precipitation.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 100.5 snowfall days, and 78.03" (1982mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:51 pm MDT.
Sunshine
In Basalt, the average sunshine in September is 11.1h.UV index
The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: An average UV index of 3 in September transforms into this advice:
Act with care - Obligation to protect against skin and eye damage is highlighted. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When does it start snowing?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Basalt, CO
- Average high temperature in September: 66.9°F
The warmest month (with the highest average high temperature) is July (75.7°F).
The month with the lowest average high temperature is December (27.9°F).
- Average low temperature in September: 37.2°F
The month with the highest average low temperature is July (43.9°F).
The coldest month (with the lowest average low temperature) is January (5.4°F).
Average pressure in September
Basalt, CO
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is January (30.24"Hg).
The month with the lowest atmospheric pressure is May (29.94"Hg).
Average wind speed in September
Basalt, CO
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is June (5.9mph).
The calmest month (with the lowest average wind speed) is January (4.3mph).
Average humidity in September
Basalt, CO
- Average humidity in September: 54%
The month with the highest relative humidity is February (88%).
The month with the lowest relative humidity is June (48%).
Average rainfall in September
Basalt, CO
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is April (2.05").
The driest month (with the least rainfall) is September (0.63").
Average rainfall days in September
Basalt, CO
- Average rainfall days in September: 9.2 days
The month with the highest number of rainy days is July (15.5 days).
The month with the least rainy days is November (5.1 days).
Average snowfall in September
Basalt, CO
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (13.94").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Basalt, CO
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (18.7 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Basalt, CO
- Average daylight in September: 12h and 2min
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 1min
The month with the most sunshine is June (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 42min).
Average sunshine days in September
Basalt, CO
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is April (7.3 days).
Average UV index in September
Basalt, CO
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Basalt, CO
- Average cloud cover in September: 14
The month with the most cloud cover is February (Cloud cover 43).
The months with the least cloud cover are June and September (Cloud cover 14).
Average visibility in September
Basalt, CO
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (4mi).
Basalt, Colorado, USA
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