September weather forecast
South Prairie, WA

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Weather in September

The first month of the autumn, September, is also an enjoyable month in South Prairie, Washington, with an average temperature varying between 67.1°F (19.5°C) and 46°F (7.8°C).

Temperature

The transition into September is accompanied by a slight temperature decrease, with the average high-temperature shifting from a moderately hot 74.1°F (23.4°C) in August to a comfortable 67.1°F (19.5°C). During September, South Prairie's temperature falls to a steady low-temperature average of 46°F (7.8°C).

Humidity

In September, the average relative humidity is 75%.

Rainfall

In September, the rain falls for 12 days. Throughout September, 1.69" (43mm) of precipitation is accumulated. In South Prairie, during the entire year, the rain falls for 189.1 days and collects up to 41.93" (1065mm) of precipitation.

Snowfall

In South Prairie, snow does not fall in May through October.

Daylight

In September, the average length of the day is 12h and 32min.
On the first day of September, sunrise is at 6:28 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:49 pm PDT.

Sunshine

In September, the average sunshine is 9h.

UV index

In September, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: A maximum high daily UV index of 3 during September translates into the following directions:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Updated: Jul 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

In South Prairie, in September, the average high-temperature is 67.1°F (19.5°C), and the average low-temperature is 46°F (7.8°C).

What is the average humidity in September?

In South Prairie, the average relative humidity in September is 75%.

How much does it rain in September?

In South Prairie, in September, it is raining for 12 days, with typically 1.69" (43mm) of accumulated precipitation.

When it does not snow?

In South Prairie, snow does not fall in May through October.

How many hours of daylight does South Prairie have in September?

In South Prairie, the average day length in September is 12h and 32min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:28 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:49 pm PDT.

How long on average sun shines in September?

In South Prairie, the average sunshine duration in September is 9h.

How high is the UV index in September?

The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
South Prairie, WA

Average temperature in September - South Prairie, WA
  • Average high temperature in September: 67.1°F

The warmest month (with the highest average high temperature) is August (74.1°F).
The month with the lowest average high temperature is December (39.9°F).

  • Average low temperature in September: 46°F

The month with the highest average low temperature is August (49.3°F).
The coldest month (with the lowest average low temperature) is December (29.8°F).

Average pressure in September
South Prairie, WA

Average pressure in September - South Prairie, WA
  • Average pressure in September: 30"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is August (29.99"Hg).

Average wind speed in September
South Prairie, WA

Average wind speed in September - South Prairie, WA
  • Average wind speed in September: 3.9mph

The windiest month (with the highest average wind speed) is January (5.3mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).

Average humidity in September
South Prairie, WA

Average humidity in September - South Prairie, WA
  • Average humidity in September: 75%

The months with the highest relative humidity are January and February (87%).
The month with the lowest relative humidity is July (70%).

Average rainfall in September
South Prairie, WA

Average rainfall in September - South Prairie, WA
  • Average rainfall in September: 1.69"

The wettest months (with the highest rainfall) are January and December (6.1").
The driest month (with the least rainfall) is July (0.63").

Average rainfall days in September
South Prairie, WA

Average rainfall days in September - South Prairie, WA
  • Average rainfall days in September: 12 days

The month with the highest number of rainy days is March (21.2 days).
The month with the least rainy days is August (7.6 days).

Average snowfall in September
South Prairie, WA

Average snowfall in September - South Prairie, WA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (5.2").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
South Prairie, WA

Average snowfall days in September - South Prairie, WA
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is February (6.3 days).
The months with the least snowfall days are June, July, August and October (0 days).

Average daylight in September /
Average sunshine in September
South Prairie, WA

Average daylight in September / Average sunshine in September - South Prairie, WA
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 36min).

  • Average sunshine in September: 9h and 0min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 0min).

Average sunshine days in September
South Prairie, WA

Average sunshine days in September - South Prairie, WA
  • Average sunshine days in September: 16.5 days

The month with the most sunshine days is July (21.2 days).
The month with the least sunshine days is March (7.8 days).

Average UV index in September
South Prairie, WA

Average UV index in September - South Prairie, WA
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 5).
The month with the lowest UV index is November (UV index 1).

Average cloud cover in September
South Prairie, WA

Average cloud cover in September - South Prairie, WA
  • Average cloud cover in September: 38

The month with the most cloud cover is March (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in September
South Prairie, WA

Average visibility in September - South Prairie, WA
  • Average visibility in September: 5mi

The months with the highest visibility are April, May, June, July, August, September and October (5mi).
The months with the lowest visibility are January, February, March, November and December (4mi).

South Prairie, Washington, USA

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