September weather forecastGrants Pass, OR
September
Weather in September
September marks the transition to Fall in Grants Pass, bringing with it a decline in average temperatures. Rainfall inches upward with an accumulation of 0.59" (15mm) over 5.3 days, marking the onset of the rainy season after months of summer drought. Despite the decrease, daylight hours offer ample sunshine during this shift. The wind speed remains steady, gently rustling the autumn leaves. A drop in atmospheric pressure indicates the coming change in the weather pattern.Temperature
The advent of September brings a subtle shift in temperature, with the average high moving from a warm 84.7°F (29.3°C) in August to a still moderately hot 77.4°F (25.2°C). Grants Pass's nights during September are marked by a pronounced drop from daytime temperatures, experiencing an average low of 45°F (7.2°C).Humidity
In September, the average relative humidity is 67%.Rainfall
In Grants Pass, Oregon, in September, during 5.3 rainfall days, 0.59" (15mm) of precipitation is typically accumulated. Throughout the year, there are 135.3 rainfall days, and 23.54" (598mm) of precipitation is accumulated.Snowfall
In Grants Pass, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:46 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:55 pm PDT.
Sunshine
The average sunshine in September is 10.4h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Boost your sun resistance with garments that are densely woven yet spacious.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grants Pass, OR
- Average high temperature in September: 77.4°F
The warmest month (with the highest average high temperature) is August (84.7°F).
The month with the lowest average high temperature is December (46°F).
- Average low temperature in September: 45°F
The month with the highest average low temperature is August (49.1°F).
The coldest month (with the lowest average low temperature) is December (31.5°F).
Average pressure in September
Grants Pass, OR
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is August (29.99"Hg).
Average wind speed in September
Grants Pass, OR
- Average wind speed in September: 3.3mph
The windiest month (with the highest average wind speed) is March (4mph).
The calmest month (with the lowest average wind speed) is August (3.2mph).
Average humidity in September
Grants Pass, OR
- Average humidity in September: 67%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is August (63%).
Average rainfall in September
Grants Pass, OR
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is December (4.02").
The driest month (with the least rainfall) is July (0.12").
Average rainfall days in September
Grants Pass, OR
- Average rainfall days in September: 5.3 days
The month with the highest number of rainy days is March (18.7 days).
The month with the least rainy days is August (2.5 days).
Average snowfall in September
Grants Pass, OR
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.5").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Grants Pass, 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
Grants Pass, OR
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 10h and 24min
The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 4h and 42min).
Average sunshine days in September
Grants Pass, OR
- Average sunshine days in September: 23.9 days
The month with the most sunshine days is July (26.7 days).
The month with the least sunshine days is March (10.8 days).
Average UV index in September
Grants Pass, 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
Grants Pass, OR
- Average cloud cover in September: 23
The month with the most cloud cover is March (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
Grants Pass, OR
- Average visibility in September: 5mi
The month with the highest visibility is August (6mi).
The months with the lowest visibility are January, February, March, April and December (4mi).
