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
With September's onset, the weather in Castle Rock reveals a slight temperature decrease, transitioning from 82°F (27.8°C) in August to a still moderately hot 75.6°F (24.2°C). Despite the significant gap from daytime peaks, Castle Rock experiences an average low-temperature of 50.7°F (10.4°C) in September.Humidity
June and September, with an average relative humidity of 45%, are the least humid months.Rainfall
In September, in Castle Rock, the rain falls for 8.6 days. Throughout September, 0.67" (17mm) of precipitation is accumulated. Throughout the year, there are 107.3 rainfall days, and 13.7" (348mm) of precipitation is accumulated.Snowfall
In Castle Rock, snow does not fall in July through September.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September in Castle Rock, sunrise is at 6:28 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:42 pm MDT.
Sunshine
In September, the average sunshine is 11h.UV index
The average daily maximum UV index in September in Castle Rock is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: In September, a regular UV index of 5 translates into these guidelines:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Castle Rock in September?
What is the least humid month in Castle Rock?
What is the average humidity in September in Castle Rock?
How much does it rain in Castle Rock in September?
When it does not snow in Castle Rock?
Does it snow in Castle Rock in September?
How many hours of daylight does Castle Rock have in September?
When are sunrise and sunset in September in Castle Rock?
How many hours of sunshine does Castle Rock have in September?
How high is the UV index in September in Castle Rock?
Average temperature in September
Castle Rock, CO
- Average high temperature in September: 75.6°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is December (39.6°F).
- Average low temperature in September: 50.7°F
The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is December (20.1°F).
Average pressure in September
Castle Rock, 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
Castle Rock, CO
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is April (7.9mph).
The calmest months (with the lowest average wind speed) are July, August and September (6.5mph).
Average humidity in September
Castle Rock, CO
- Average humidity in September: 45%
The month with the highest relative humidity is February (66%).
The months with the lowest relative humidity are June and September (45%).
Average rainfall in September
Castle Rock, CO
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is May (2.24").
The driest months (with the least rainfall) are January and December (0.55").
Average rainfall days in September
Castle Rock, CO
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is November (3 days).
Average snowfall in September
Castle Rock, CO
- Average snowfall in September: 0"
The month with the highest snowfall is April (7.13").
The months with the least snowfall are July, August and September (0").
Average snowfall days in September
Castle Rock, CO
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (9.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Castle Rock, 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 0min
The months with the most sunshine are June, July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 6h and 48min).
Average sunshine days in September
Castle Rock, CO
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is November (22.8 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in September
Castle Rock, CO
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in September
Castle Rock, CO
- Average cloud cover in September: 15
The month with the most cloud cover is April (Cloud cover 27).
The month with the least cloud cover is September (Cloud cover 15).
Average visibility in September
Castle Rock, 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).
Castle Rock, Colorado, USA
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