September weather forecastUnion, UT
September
Weather in September
The first month of the autumn, September, is still a warm month in Union, Utah, with temperature in the range of an average low of 50.9°F (10.5°C) and an average high of 73.4°F (23°C).Temperature
The transition into September subtly indicates a reduction in the average high-temperature, down to a still moderately hot 73.4°F (23°C) from August's 82°F (27.8°C). Despite a significant deviation from daily highs, September sees an average nighttime temperature of 50.9°F (10.5°C).Humidity
In Union, the average relative humidity in September is 43%.Rainfall
In September, the rain falls for 8 days. Throughout September, 0.94" (24mm) of precipitation is accumulated. In Union, during the entire year, the rain falls for 110.7 days and collects up to 16.06" (408mm) of precipitation.Snowfall
In Union, snow does not fall in June through September.Daylight
In Union, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:55 am and sunset at 7:59 pm. On the last day of September, sunrise is at 7:23 am and sunset at 7:10 pm MDT.
Sunshine
The average sunshine in September in Union is 10h.UV index
In Union, the average daily maximum UV index in September is 4. 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: A maximum high daily UV index of 4 during September translates into the following directions:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Union, UT
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 50.9°F
The month with the highest average low temperature is July (60.3°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in September
Union, UT
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Union, UT
- Average wind speed in September: 5.7mph
The windiest months (with the highest average wind speed) are March and April (6.3mph).
The calmest month (with the lowest average wind speed) is January (4.8mph).
Average humidity in September
Union, UT
- Average humidity in September: 43%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (37%).
Average rainfall in September
Union, UT
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is March (1.97").
The driest month (with the least rainfall) is June (0.59").
Average rainfall days in September
Union, UT
- Average rainfall days in September: 8 days
The month with the highest number of rainy days is March (13.2 days).
The month with the least rainy days is June (6.3 days).
Average snowfall in September
Union, UT
- Average snowfall in September: 0"
The month with the highest snowfall is January (10.71").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Union, UT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Union, UT
- Average daylight in September: 12h and 24min
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 18min).
- Average sunshine in September: 10h and 0min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 24min).
Average sunshine days in September
Union, UT
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is June (21.4 days).
The month with the least sunshine days is February (12.9 days).
Average UV index in September
Union, UT
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Union, UT
- Average cloud cover in September: 12
The month with the most cloud cover is February (Cloud cover 41).
The month with the least cloud cover is August (Cloud cover 10).
Average visibility in September
Union, UT
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).





