September weather forecastHamilton, CO
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Hamilton, Colorado, with an average temperature varying between 72.5°F (22.5°C) and 46.2°F (7.9°C).Temperature
With the onset of September, Hamilton's average high-temperature slightly adjusts, moderately receding from August's warm 80.6°F (27°C) to an agreeable 72.5°F (22.5°C). Hamilton undergoes a major shift from daytime highs, averaging a chilly 46.2°F (7.9°C) during the night in September.Humidity
The average relative humidity in September in Hamilton is 42%.Rainfall
August and September are months with the least rain in Hamilton when the rain falls for 6.2 days and typically aggregates up to 0.39" (10mm) of rain.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows in Hamilton, Colorado. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Hamilton, during the entire year, snow falls for 68.6 days and aggregates up to 41.3" (1049mm) of snow.Daylight
In September, the average length of the day in Hamilton is 12h and 26min.On the first day of September in Hamilton, sunrise is at 6:38 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:53 pm MDT.
Sunshine
In Hamilton, the average sunshine in September is 11h.UV index
In September, the average daily maximum UV index in Hamilton is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. Direct Sun exposure should be minimized especially during midday when radiation is most intense. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hamilton, CO
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in September: 46.2°F
The month with the highest average low temperature is July (51.8°F).
The coldest month (with the lowest average low temperature) is January (10.9°F).
Average pressure in September
Hamilton, CO
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.27"Hg).
The months with the lowest atmospheric pressure are May and June (29.92"Hg).
Average wind speed in September
Hamilton, CO
- Average wind speed in September: 7.2mph
The windiest month (with the highest average wind speed) is April (7.9mph).
The calmest month (with the lowest average wind speed) is January (5.2mph).
Average humidity in September
Hamilton, CO
- Average humidity in September: 42%
The months with the highest relative humidity are January and February (84%).
The month with the lowest relative humidity is August (41%).
Average rainfall in September
Hamilton, CO
- Average rainfall in September: 0.39"
The wettest month (with the highest rainfall) is April (1.38").
The driest months (with the least rainfall) are August and September (0.39").
Average rainfall days in September
Hamilton, CO
- Average rainfall days in September: 6.2 days
The month with the highest number of rainy days is April (10.8 days).
The month with the least rainy days is January (3.1 days).
Average snowfall in September
Hamilton, CO
- Average snowfall in September: 0.04"
The month with the highest snowfall is December (7.28").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Hamilton, CO
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (13.8 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Hamilton, CO
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 11h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 18min).
Average sunshine days in September
Hamilton, CO
- Average sunshine days in September: 21.6 days
The month with the most sunshine days is June (22.8 days).
The month with the least sunshine days is February (13.3 days).
Average UV index in September
Hamilton, CO
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Hamilton, CO
- Average cloud cover in September: 12
The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is September (Cloud cover 12).
Average visibility in September
Hamilton, CO
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).
