September weather forecastHeyburn, ID
September
Weather in September
September, the first month of the autumn in Heyburn, is still a warm month, with an average temperature fluctuating between 76.1°F (24.5°C) and 53.8°F (12.1°C).Temperature
The onset of September brings a small change in high-temperatures, falling from a hot 86.9°F (30.5°C) in August to a warm 76.1°F (24.5°C). During September nights, Heyburn documents a marked contrast from daily highs, with an average temperature of 53.8°F (12.1°C).Humidity
In September, the average relative humidity is 35%.Rainfall
In September, the rain falls for 6.3 days. Throughout September, 0.43" (11mm) of precipitation is accumulated. In Heyburn, during the entire year, the rain falls for 105.2 days and collects up to 10.63" (270mm) of precipitation.Snowfall
Months with snowfall in Heyburn are January through May, September through December. September is the first month it typically snows in Heyburn. Throughout September, in the average 0.1 snowfall days, it receives 0.16" (4mm) of snow. Throughout the year, there are 50.9 snowfall days, and 24.57" (624mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 7:00 am and sunset at 8:08 pm. On the last day of September, sunrise is at 7:32 am and sunset at 7:17 pm MDT.
Sunshine
In Heyburn, the average sunshine in September is 9.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: A daily high UV index of 4 in September leads to these guidelines:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Heyburn, ID
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (32.5°F).
- Average low temperature in September: 53.8°F
The months with the highest average low temperature are July and August (60.8°F).
The coldest month (with the lowest average low temperature) is December (21.6°F).
Average pressure in September
Heyburn, ID
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Heyburn, ID
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (9.8mph).
The calmest month (with the lowest average wind speed) is January (7.1mph).
Average humidity in September
Heyburn, ID
- Average humidity in September: 35%
The month with the highest relative humidity is January (80%).
The months with the lowest relative humidity are July and August (30%).
Average rainfall in September
Heyburn, ID
- Average rainfall in September: 0.43"
The wettest month (with the highest rainfall) is March (1.46").
The driest month (with the least rainfall) is July (0.28").
Average rainfall days in September
Heyburn, ID
- Average rainfall days in September: 6.3 days
The months with the highest number of rainy days are March and April (14 days).
The months with the least rainy days are July and August (5.2 days).
Average snowfall in September
Heyburn, ID
- Average snowfall in September: 0.16"
The month with the highest snowfall is December (6.54").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Heyburn, ID
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (13 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Heyburn, ID
- Average daylight in September: 12h and 30min
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 6min).
- Average sunshine in September: 9h and 36min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 42min).
Average sunshine days in September
Heyburn, ID
- Average sunshine days in September: 21.6 days
The month with the most sunshine days is July (22.6 days).
The month with the least sunshine days is March (12 days).
Average UV index in September
Heyburn, ID
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Heyburn, ID
- Average cloud cover in September: 14
The month with the most cloud cover is December (Cloud cover 40).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Heyburn, ID
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





