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 witnesses a gentle descent in average high-temperature, descending from August's warm 80.4°F (26.9°C) to an agreeable 73°F (22.8°C). Gresham experiences a dramatic descent in temperature during September, with the average nighttime reading settling at a cool 50.2°F (10.1°C).Humidity
The average relative humidity in September is 69%.Rainfall
In Gresham, in September, during 9.7 rainfall days, 1.85" (47mm) of precipitation is typically accumulated. Throughout the year, there are 165.6 rainfall days, and 34.65" (880mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:46 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:51 pm PDT.
Sunshine
In Gresham, the average sunshine in September is 9.2h.UV index
In Gresham, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Gresham?
What is the average humidity in September in Gresham?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Gresham have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Gresham have in September?
What is the UV index reading in September in Gresham?
Average temperature in September
Gresham, OR
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is August (80.4°F).
The month with the lowest average high temperature is December (43.7°F).
- Average low temperature in September: 50.2°F
The month with the highest average low temperature is August (53.4°F).
The coldest month (with the lowest average low temperature) is December (33.8°F).
Average pressure in September
Gresham, OR
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Gresham, OR
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is January (6.8mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity in September
Gresham, OR
- Average humidity in September: 69%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is August (64%).
Average rainfall in September
Gresham, OR
- Average rainfall in September: 1.85"
The wettest month (with the highest rainfall) is December (5.31").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in September
Gresham, OR
- Average rainfall days in September: 9.7 days
The month with the highest number of rainy days is March (19.3 days).
The month with the least rainy days is August (4.4 days).
Average snowfall in September
Gresham, OR
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.73").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Gresham, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Gresham, OR
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 9h and 1min
The months with the most sunshine are July and August (Average sunshine: 10h and 54min).
The months with the least sunshine are January and February (Average sunshine: 4h and 12min).
Average sunshine days in September
Gresham, OR
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is July (25 days).
The month with the least sunshine days is February (9.7 days).
Average UV index in September
Gresham, OR
- 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
Gresham, OR
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 24).
Average visibility in September
Gresham, OR
- Average visibility in September: 6mi
The months with the highest visibility are August, September and October (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, November and December (5mi).
Gresham, Oregon, USA
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