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The weather in September in Rainier

It's warm in September in Rainier with an average temperature of 23°C. Temperatures this month range from a low of 19°C to a high of 26°C. At night, you can expect temperatures between 8°C and 13°C.

Looking for sun? September isn’t a good month to be in Rainier. The temperature is nice, but there’s too much chance of rain.

Average temperatures and precipitation

This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Rainier, Washington. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.

Temperature records

With 33°C in 2020, Rainier reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 12°C in 2019. The extreme nighttime temperatures ranged from a lowest recorded value of 0°C to a highest value of 18°C.

Rainfall amount

In September, there is an average of 126 mm of precipitation, spread over 15 days. The wind speed is around 3 Bft, mostly coming from the South.

Daily weather in September for Rainier

Click on any day in September to get detailed info about the usual weather on that day in Rainier. Check out the historical temperatures and precipitation over the past 10 years on this day.

September weather comparison

  Rainier New York
Average temperature 23°C 27°C
Max. temperature 26°C 31°C
Min. temperature 8°C -5°C
Total precipitation 126 mm 57 mm
Rainy days 15 days 9 days

Start of September

The month of September starts in Rainier with warm temps, averaging around 25°C during the day and nights around 12°C.

Mid September

By mid-September, daytime temps drop to around 22°C, with nights around 11°C. During this part of the month, you might see regular precipitation, but there will also be some sunny days.

End of September

By the end of September, the average daytime temperature in Rainier is around 21°C, while nighttime temps are about 10°C. Expect regular precipitation, but if you’re lucky, you’ll also get some dry and sunny days.

UV index

The UV index is a maximum of 5 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.

Check out the climate of Rainier for all months and discover the best travel time

Temperature charts

These charts show the average temperatures in September in Rainier, Washington. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.

Daily Temperature in September in Rainier

Temperature in September in Rainier over the years

Precipitation charts

These charts show the average amount of precipitation in September in Rainier, Washington. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.

Daily Precipitation in September in Rainier

Total precipitation in September in Rainier over the years

Daily UV index in September in Rainier

This chart shows the average daily UV index in September in Rainier, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.

Weather experiences in September in Rainier

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Average weather in Rainier by month

Click on a month below to see detailed weather info for Rainier. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.