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
Firth's progression into September includes a drop in the average high-temperature, from a moderately hot 83.3°F (28.5°C) in August to a pleasant 72.9°F (22.7°C). The temperature notes a substantial fall from the daily peak to an average of 49.3°F (9.6°C) during September nights.Humidity
In September, the average relative humidity is 41%.Rainfall
In Firth, in September, during 10.1 rainfall days, 1.06" (27mm) of precipitation is typically accumulated. In Firth, during the entire year, the rain falls for 124.6 days and collects up to 12.24" (311mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.2" (5mm) of snow. Throughout the year, in Firth, there are 75.1 snowfall days, and 30.59" (777mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:53 am and sunset at 8:03 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:10 pm MDT.
Sunshine
In Firth, the average sunshine in September is 9.9h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: The daily high UV index of 4 during September translates into the following recommendations:
Undertake precautions - Guarding against sun damage is counselled. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. 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 temperature in September?
What is the average humidity in September?
How many days does it rain in September?
When does it start to snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Firth have in September?
What is the UV index reading in September?
Average temperature in September
Firth, ID
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (27.9°F).
- Average low temperature in September: 49.3°F
The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is January (14.7°F).
Average pressure in September
Firth, ID
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.3"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Firth, ID
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (8.9mph).
The calmest month (with the lowest average wind speed) is January (6mph).
Average humidity in September
Firth, ID
- Average humidity in September: 41%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are July and August (36%).
Average rainfall in September
Firth, ID
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is May (1.57").
The driest month (with the least rainfall) is July (0.51").
Average rainfall days in September
Firth, ID
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is January (6.1 days).
Average snowfall in September
Firth, ID
- Average snowfall in September: 0.2"
The month with the highest snowfall is January (7.44").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Firth, ID
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (16.7 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Firth, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 9h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).
Average sunshine days in September
Firth, ID
- Average sunshine days in September: 17.3 days
The month with the most sunshine days is October (18.9 days).
The month with the least sunshine days is March (10 days).
Average UV index in September
Firth, ID
- 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 and December (UV index 1).
Average cloud cover in September
Firth, ID
- Average cloud cover in September: 16
The month with the most cloud cover is February (Cloud cover 51).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Firth, ID
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).
Firth, Idaho, USA
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