September weather forecastSilt, CO
September
Weather in September
September, the first month of the autumn in Silt, is also an agreeable month, with an average temperature ranging between max 70.9°F (21.6°C) and min 43.9°F (6.6°C).Temperature
The transition into September involves a small decrease in the average high-temperature, dipping slightly from a moderately hot 78.4°F (25.8°C) in August to a pleasant 70.9°F (21.6°C). Silt documents a marked decrease from day to night, with an average low of 43.9°F (6.6°C) throughout September.Humidity
In Silt, the average relative humidity in September is 48%.Rainfall
The month with the least rainfall is September, when the rain falls for 7.9 days and typically collects 0.51" (13mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Silt, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:39 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:54 pm MDT.
Sunshine
The average sunshine in September is 11h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for average individuals.Note: The maximum UV index of 4 during September leads to these instructions:
Exercise prevention - Warding off sunburn is urged. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Silt, CO
- Average high temperature in September: 70.9°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 43.9°F
The month with the highest average low temperature is July (50.4°F).
The coldest month (with the lowest average low temperature) is January (12°F).
Average pressure in September
Silt, CO
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is May (29.93"Hg).
Average wind speed in September
Silt, CO
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is June (6.2mph).
The calmest month (with the lowest average wind speed) is January (4.1mph).
Average humidity in September
Silt, CO
- Average humidity in September: 48%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is June (43%).
Average rainfall in September
Silt, CO
- Average rainfall in September: 0.51"
The wettest month (with the highest rainfall) is April (1.57").
The driest month (with the least rainfall) is September (0.51").
Average rainfall days in September
Silt, CO
- Average rainfall days in September: 7.9 days
The month with the highest number of rainy days is April (14 days).
The month with the least rainy days is June (5.9 days).
Average snowfall in September
Silt, CO
- Average snowfall in September: 0"
The month with the highest snowfall is February (8.74").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Silt, CO
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Silt, 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 0min
The months with the most sunshine are June, July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 6h and 6min).
Average sunshine days in September
Silt, CO
- Average sunshine days in September: 17.7 days
The month with the most sunshine days is June (20.7 days).
The month with the least sunshine days is April (11.7 days).
Average UV index in September
Silt, CO
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Silt, CO
- Average cloud cover in September: 12
The month with the most cloud cover is February (Cloud cover 39).
The months with the least cloud cover are June and September (Cloud cover 12).
Average visibility in September
Silt, CO
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).





