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
The start of September signals a gentle decrease in the average high-temperature, transitioning from a hot 88°F (31.1°C) in August to a warm 79.7°F (26.5°C). A noticeable temperature swing characterizes Johnstown's September nights, dipping to an average of 53.4°F (11.9°C).Humidity
August and September, with an average relative humidity of 42%, are the least humid months.Rainfall
In Johnstown, in September, it is raining for 7.6 days, with typically 0.75" (19mm) of accumulated precipitation. Throughout the year, there are 107.4 rainfall days, and 11.3" (287mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Johnstown, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:30 pm. On the last day of September, in Johnstown, Colorado, sunrise is at 6:55 am and sunset at 6:42 pm MDT.
Sunshine
In Johnstown, the average sunshine in September is 10.9h.UV index
In Johnstown, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The daily high UV index of 4 during September translates into the following recommendations:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Johnstown?
What are the least humid months in Johnstown?
What is the average humidity in September in Johnstown?
How much does it rain in Johnstown in September?
When it does not snow in Johnstown?
Does it snow in Johnstown in September?
What is the average length of the day in September in Johnstown?
What time are sunrise and sunset in September in Johnstown?
How long on average sun shines in September in Johnstown?
What is the UV index reading in September in Johnstown?
Average temperature in September
Johnstown, CO
- Average high temperature in September: 79.7°F
The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is December (39.4°F).
- Average low temperature in September: 53.4°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is December (20.7°F).
Average pressure in September
Johnstown, CO
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Johnstown, CO
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is April (7.3mph).
The calmest month (with the lowest average wind speed) is December (5.5mph).
Average humidity in September
Johnstown, CO
- Average humidity in September: 42%
The months with the highest relative humidity are January, February and December (63%).
The months with the lowest relative humidity are August and September (42%).
Average rainfall in September
Johnstown, CO
- Average rainfall in September: 0.75"
The wettest month (with the highest rainfall) is May (2.13").
The driest months (with the least rainfall) are January and December (0.39").
Average rainfall days in September
Johnstown, CO
- Average rainfall days in September: 7.6 days
The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is November (3.7 days).
Average snowfall in September
Johnstown, CO
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.53").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Johnstown, CO
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (9.6 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Johnstown, CO
- Average daylight in September: 12h and 2min
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 24min).
- Average sunshine in September: 10h and 5min
The month with the most sunshine is June (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 42min).
Average sunshine days in September
Johnstown, CO
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is January (22.4 days).
The month with the least sunshine days is July (11.4 days).
Average UV index in September
Johnstown, CO
- Average UV index in September: 4
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
Johnstown, CO
- Average cloud cover in September: 16
The month with the most cloud cover is April (Cloud cover 27).
The months with the least cloud cover are June and September (Cloud cover 16).
Average visibility in September
Johnstown, 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).
Johnstown, Colorado, USA
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