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 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
As September takes hold, the average high-temperature is a still warm 78.6°F (25.9°C), nearly mirroring that of the previous month. Union City's average low-temperature of 56.7°F (13.7°C) in September reflects a significant disparity from the daytime highs.Humidity
September and October, with an average relative humidity of 62%, are the least humid months in Union City.Rainfall
January through May, September through December are months with rainfall in Union City. September is the first month it rains. Throughout September, in the average 1.2 rainfall days, it receives 0.04" (1mm) of precipitation. Throughout the year, in Union City, there are 38 rainfall days, and 2.13" (54mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September in Union City, sunrise is at 6:39 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:52 pm PDT.
Sunshine
The average sunshine in September is 11.1h.UV index
In Union City, California, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The average daily UV index of 5 in September transforms into the following instructions:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. The solar radiation around mid-day is intense; avoid the Sun and stay safe. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Frequently asked questions
What are September temperatures in Union City?
What are the least humid months in Union City?
What is the average humidity in September in Union City?
When does it start raining in Union City?
What is the average length of the day in September in Union City?
When are sunrise and sunset in September in Union City?
How many hours of sunshine does Union City have in September?
What is the UV index intensity in September in Union City?
Average temperature in September
Union City, CA
- Average high temperature in September: 78.6°F
The warmest months (with the highest average high temperature) are July and August (80.1°F).
The month with the lowest average high temperature is December (56.3°F).
- Average low temperature in September: 56.7°F
The months with the highest average low temperature are August and September (56.7°F).
The coldest month (with the lowest average low temperature) is December (43.7°F).
Average pressure in September
Union City, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in September
Union City, CA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is May (6.4mph).
The calmest months (with the lowest average wind speed) are October and November (4.7mph).
Average humidity in September
Union City, CA
- Average humidity in September: 62%
The month with the highest relative humidity is March (73%).
The months with the lowest relative humidity are September and October (62%).
Average rainfall in September
Union City, CA
- Average rainfall in September: 0.04"
The wettest month (with the highest rainfall) is February (0.47").
The driest months (with the least rainfall) are June, July and August (0").
Average rainfall days in September
Union City, CA
- Average rainfall days in September: 1.2 days
The month with the highest number of rainy days is March (7.3 days).
The month with the least rainy days is July (0.3 days).
Average daylight in September /
Average sunshine in September
Union City, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 11h and 1min
The month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in September
Union City, CA
- Average sunshine days in September: 28.5 days
The months with the most sunshine days are July and August (30.4 days).
The month with the least sunshine days is February (22.2 days).
Average UV index in September
Union City, CA
- 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, November and December (UV index 3).
Average cloud cover in September
Union City, CA
- Average cloud cover in September: 9
The month with the most cloud cover is March (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 6).
Average visibility in September
Union City, CA
- 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).
Union City, California, USA
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