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
September implies a gentle temperature shift, with average high-temperatures reducing from August's moderately hot 85.1°F (29.5°C) to a still warm 74.1°F (23.4°C). Pomona, in September, displays a significant temperature downturn during the night, with an average reading of 51.8°F (11°C).Humidity
In Pomona, the average relative humidity in September is 50%.Rainfall
In Pomona, in September, during 4.8 rainfall days, 0.28" (7mm) of precipitation is typically accumulated. Throughout the year, there are 87.6 rainfall days, and 5.94" (151mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, September, November and December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.12" (3mm) of snow. In Pomona, during the entire year, snow falls for 19.9 days and aggregates up to 8.62" (219mm) of snow.Daylight
In September, the average length of the day is 12h and 32min.On the first day of September, sunrise is at 6:22 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:42 pm PDT.
Sunshine
In September, the average sunshine is 11.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Take precautions - Protection against sunburn is recommended. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. 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 usual temperature for Pomona in September?
What is the average humidity in September?
How much does it rain in September?
When does it start snowing in Pomona?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Pomona have in September?
What is the UV index reading in September?
Average temperature in September
Pomona, WA
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is August (85.1°F).
The month with the lowest average high temperature is December (36°F).
- Average low temperature in September: 51.8°F
The month with the highest average low temperature is August (58.8°F).
The coldest month (with the lowest average low temperature) is December (23.9°F).
Average pressure in September
Pomona, WA
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).
Average wind speed in September
Pomona, WA
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is June (7.4mph).
The calmest month (with the lowest average wind speed) is December (4.2mph).
Average humidity in September
Pomona, WA
- Average humidity in September: 50%
The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are July and August (41%).
Average rainfall in September
Pomona, WA
- Average rainfall in September: 0.28"
The wettest month (with the highest rainfall) is December (0.87").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in September
Pomona, WA
- Average rainfall days in September: 4.8 days
The month with the highest number of rainy days is March (10.8 days).
The month with the least rainy days is July (2.3 days).
Average snowfall in September
Pomona, WA
- Average snowfall in September: 0.12"
The month with the highest snowfall is December (3.07").
The months with the least snowfall are May, June, July, August and October (0").
Average snowfall days in September
Pomona, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (5.7 days).
The months with the least snowfall days are May, June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Pomona, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 11h and 1min
The months with the most sunshine are July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 30min).
Average sunshine days in September
Pomona, WA
- Average sunshine days in September: 23.2 days
The month with the most sunshine days is July (27.6 days).
The month with the least sunshine days is February (15.5 days).
Average UV index in September
Pomona, WA
- 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, February, November and December (UV index 2).
Average cloud cover in September
Pomona, WA
- Average cloud cover in September: 15
The month with the most cloud cover is January (Cloud cover 40).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in September
Pomona, WA
- 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).
Pomona, Washington, USA
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