September weather forecastRochester, WA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Rochester, Washington, with an average temperature varying between 70.2°F (21.2°C) and 47.3°F (8.5°C).Temperature
The beginning of September brings a slight decrease in the average high-temperature, transitioning from a warm 77.4°F (25.2°C) in August to an agreeable 70.2°F (21.2°C). In the face of high daytime temperatures, Rochester witnesses a consistent average nighttime low of 47.3°F (8.5°C) during September.Humidity
In Rochester, the average relative humidity in September is 79%.Rainfall
In Rochester, in September, it is raining for 10.6 days, with typically 1.14" (29mm) of accumulated precipitation. In Rochester, during the entire year, the rain falls for 168 days and collects up to 23.94" (608mm) of precipitation.Snowfall
In Rochester, snow does not fall in April through October.Daylight
In September, the average length of the day is 12h and 32min.On the first day of the month, sunrise is at 6:33 am and sunset at 7:50 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:53 pm PDT.
Sunshine
In September, the average sunshine is 8.3h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the average person.Note: In September, the UV index of 4 transforms into the following advice:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rochester, WA
- Average high temperature in September: 70.2°F
The warmest month (with the highest average high temperature) is August (77.4°F).
The month with the lowest average high temperature is December (42.6°F).
- Average low temperature in September: 47.3°F
The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (33.1°F).
Average pressure in September
Rochester, WA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.02"Hg).
Average wind speed in September
Rochester, WA
- Average wind speed in September: 3.6mph
The windiest months (with the highest average wind speed) are January, March and November (4.5mph).
The calmest month (with the lowest average wind speed) is September (3.6mph).
Average humidity in September
Rochester, WA
- Average humidity in September: 79%
The month with the highest relative humidity is November (90%).
The month with the lowest relative humidity is July (73%).
Average rainfall in September
Rochester, WA
- Average rainfall in September: 1.14"
The wettest month (with the highest rainfall) is January (3.86").
The driest month (with the least rainfall) is July (0.35").
Average rainfall days in September
Rochester, WA
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (5.6 days).
Average snowfall in September
Rochester, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.54").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Rochester, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.7 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
Rochester, WA
- Average daylight in September: 12h and 30min
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: 8h and 18min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is December (Average sunshine: 3h and 30min).
Average sunshine days in September
Rochester, WA
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is August (20.9 days).
The months with the least sunshine days are February and March (9.3 days).
Average UV index in September
Rochester, WA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Rochester, WA
- Average cloud cover in September: 47
The month with the most cloud cover is January (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 38).
Average visibility in September
Rochester, WA
- Average visibility in September: 4mi
The month with the highest visibility is July (5mi).
The months with the lowest visibility are January, February, March, April, May, June, August, September, October, November and December (4mi).
