September weather forecastHayden, CO
September
Weather in September
September, the first month of the autumn in Hayden, is also an agreeable month, with an average temperature fluctuating between 43°F (6.1°C) and 70°F (21.1°C).Temperature
September is characterized by a mild reduction in the average high-temperature, from a warm 78.1°F (25.6°C) in August to an agreeable 70°F (21.1°C). The nighttime temperature during September displays a significant divergence from daily peaks, averaging at a chilly 43°F (6.1°C).Humidity
In Hayden, the average relative humidity in September is 47%.Rainfall
In Hayden, Colorado, in September, during 8.1 rainfall days, 0.59" (15mm) of precipitation is typically accumulated. In Hayden, during the entire year, the rain falls for 96.4 days and collects up to 13.11" (333mm) of precipitation.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.12" (3mm) of snow. Throughout the year, there are 87.1 snowfall days, and 60.47" (1536mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:40 pm. On the last day of September, sunrise is at 7:05 am and sunset at 6:52 pm MDT.
Sunshine
In Hayden, 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 radiation for average individuals.Note: In September, the maximum UV index of 4 suggests this advice:
Take necessary precautions - Protection from skin and eye injury is mandatory. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Take to heart! Snow reflection can almost magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hayden, CO
- Average high temperature in September: 70°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (27.5°F).
- Average low temperature in September: 43°F
The month with the highest average low temperature is July (49.6°F).
The coldest month (with the lowest average low temperature) is January (9°F).
Average pressure in September
Hayden, CO
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.26"Hg).
The month with the lowest atmospheric pressure is May (29.92"Hg).
Average wind speed in September
Hayden, CO
- Average wind speed in September: 6.6mph
The windiest months (with the highest average wind speed) are April and June (7.1mph).
The calmest month (with the lowest average wind speed) is January (5.2mph).
Average humidity in September
Hayden, CO
- Average humidity in September: 47%
The months with the highest relative humidity are January and February (86%).
The month with the lowest relative humidity is August (45%).
Average rainfall in September
Hayden, CO
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is April (1.81").
The driest month (with the least rainfall) is August (0.55").
Average rainfall days in September
Hayden, CO
- Average rainfall days in September: 8.1 days
The months with the highest number of rainy days are April and May (12.3 days).
The month with the least rainy days is November (5 days).
Average snowfall in September
Hayden, CO
- Average snowfall in September: 0.12"
The month with the highest snowfall is January (11.34").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Hayden, CO
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (16.7 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Hayden, 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 months with the most sunshine are June and July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 24min).
Average sunshine days in September
Hayden, CO
- Average sunshine days in September: 17.6 days
The month with the most sunshine days is June (19.6 days).
The month with the least sunshine days is April (10.2 days).
Average UV index in September
Hayden, 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, April, October, November and December (UV index 2).
Average cloud cover in September
Hayden, CO
- Average cloud cover in September: 13
The month with the most cloud cover is February (Cloud cover 44).
The months with the least cloud cover are June, August and September (Cloud cover 13).
Average visibility in September
Hayden, 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).





