Weather in September
Temperature
The arrival of September suggests a slight decrease in the average high-temperature, moving from an enjoyable 64.6°F (18.1°C) in August to a mild 58.1°F (14.5°C). Mount Rainier National Park sees an average low-temperature of 39.7°F (4.3°C) during September.Rainfall
In Mount Rainier National Park, in September, during 9.6 rainfall days, 4.72" (120mm) of precipitation is typically accumulated. Throughout the year, there are 188.7 rainfall days, and 118.31" (3005mm) of precipitation is accumulated.Snowfall
January through December are months with snowfall. In September, it is snowing for 0.7 days. Throughout September, 1.42" (36mm) of snow is accumulated. In Mount Rainier National Park, during the entire year, snow falls for 121.5 days and aggregates up to 670.91" (17041mm) of snow.Daylight
In Mount Rainier National Park, the average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:45 pm. On the last day of September, sunrise is at 7:05 am and sunset at 6:47 pm PDT.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
How many days does it rain in September?
How many days does it snow in September?
How many hours of daylight does Mount Rainier National Park have in September?
When are sunrise and sunset in September?
Average temperature in September
Mount Rainier National Park, WA
- Average high temperature in September: 58.1°F
The warmest month (with the highest average high temperature) is August (64.5°F).
The month with the lowest average high temperature is December (33.8°F).
- Average low temperature in September: 39.7°F
The month with the highest average low temperature is August (43.9°F).
The coldest month (with the lowest average low temperature) is December (21.1°F).
Average rainfall in September
Mount Rainier National Park, WA
- Average rainfall in September: 4.7"
The wettest month (with the highest rainfall) is November (20.3").
The driest months (with the least rainfall) are July and August (2").
Average rainfall days in September
Mount Rainier National Park, WA
- Average rainfall days in September: 9.6 days
The month with the highest number of rainy days is November (21.7 days).
The month with the least rainy days is August (6.6 days).
Average snowfall in September
Mount Rainier National Park, WA
- Average snowfall in September: 1.4"
The months with the highest snowfall are January, November and December (99.9").
The month with the least snowfall is August (0.1").
Average snowfall days in September
Mount Rainier National Park, WA
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is March (19.5 days).
The month with the least snowfall days is August (0.1 days).
Average daylight in September
Mount Rainier National Park, 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).
Mount Rainier National Park, Washington, USA
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