September weather forecastCastlewood, CO
September
Weather in September
The first month of the autumn, September, is still a warm month in Castlewood, Colorado, with an average temperature fluctuating between 52.5°F (11.4°C) and 77.7°F (25.4°C).Temperature
Castlewood's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's moderately hot 84.4°F (29.1°C) to a still warm 77.7°F (25.4°C). Against the high September temperatures, Castlewood records an average drop to a fresh 52.5°F (11.4°C) at night.Humidity
June, August and September, with an average relative humidity of 43%, are the least humid months in Castlewood.Rainfall
The month with the least rainfall is September, when the rain falls for 6.5 days and typically collects 0.47" (12mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:30 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:43 pm MDT.
Sunshine
In Castlewood, the average sunshine in September is 11h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: In September, a daily UV index of 5 turns into the following recommendations:
Act with care - The need to guard against sun damage is communicated. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Castlewood, CO
- Average high temperature in September: 77.7°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is December (40.3°F).
- Average low temperature in September: 52.5°F
The month with the highest average low temperature is July (59.2°F).
The coldest month (with the lowest average low temperature) is December (20.7°F).
Average pressure in September
Castlewood, CO
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are April and June (29.91"Hg).
Average wind speed in September
Castlewood, CO
- Average wind speed in September: 6.6mph
The windiest month (with the highest average wind speed) is April (7.8mph).
The calmest months (with the lowest average wind speed) are August and December (6.5mph).
Average humidity in September
Castlewood, CO
- Average humidity in September: 43%
The month with the highest relative humidity is February (65%).
The months with the lowest relative humidity are June, August and September (43%).
Average rainfall in September
Castlewood, CO
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is May (2.2").
The driest month (with the least rainfall) is September (0.47").
Average rainfall days in September
Castlewood, CO
- Average rainfall days in September: 6.5 days
The month with the highest number of rainy days is May (14.2 days).
The month with the least rainy days is November (3.4 days).
Average snowfall in September
Castlewood, CO
- Average snowfall in September: 0"
The month with the highest snowfall is April (6.34").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Castlewood, CO
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (9.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Castlewood, 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 and July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 48min).
Average sunshine days in September
Castlewood, CO
- Average sunshine days in September: 21 days
The month with the most sunshine days is November (23.2 days).
The month with the least sunshine days is April (12.7 days).
Average UV index in September
Castlewood, CO
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Castlewood, CO
- Average cloud cover in September: 15
The month with the most cloud cover is April (Cloud cover 26).
The months with the least cloud cover are June and September (Cloud cover 15).
Average visibility in September
Castlewood, 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).
