Weather in Olympia, Washington for September 2026
Until now, September 2026 in Olympia is cooler than usual, with temperatures averaging 23 °F, this is 2.2 °F below the typical seasonal average.
Expect cooler weather in the next days in Olympia with the forecast suggesting a temperature of 21.7 °F, lower than the historical average.
In general, the average temperature in Olympia at the beginning of September is 25.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 18.6 °F by the end of September.
Olympia experiences moderate rainfall in September, with an average of 9 rainy days and a total precipitation of 44.7 mm.
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Olympia Weather September
Temperatures trend during September in Olympia
September weather in Olympia day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 24° /13° | 0 mm | 4 | |
| Sept. 2 | Overcast | 23° /12° | 15.8 mm | 4 | |
| Sept. 3 | Overcast | 24° /13° | 7.3 mm | 4 | |
| Sept. 4 | Overcast | 27° /12° | 0 mm | 6 | |
| Sept. 5 |  Sunny | 29° /13° | 0.3 mm | 6 | |
| Sept. 6 | Sunny | 27° /12° | 0 mm | 6 | |
| Sept. 7 |  Partly cloudy | 25° /14° | 1 mm | 6 | |
| Sept. 8 | Sunny | 25° /12° | 0 mm | 6 | |
| Sept. 9 | Overcast | 23° /12° | 1.9 mm | 4 | |
| Sept. 10 | Overcast | 22° /11° | 0.4 mm | 4 | |
| Sept. 11 | Overcast | 20° /9° | 0 mm | 4.1 | |
| Sept. 12 | Overcast | 17° /11° | 4.8 mm | 3.6 | |
| Sept. 13 |  Fog | 21° /11° | 0.3 mm | 3.6 | |
| Sept. 14 | Fog | 20° /9° | 0.1 mm | 4.8 | |
| Sept. 15 | Sunny | 22° /9° | 0 mm | 6 | |
| Sept. 16 | Sunny | 28° /9° | 0 mm | 7 | |
| Sept. 17 | Sunny | 30° /11° | 0 mm | 7 | |
| Sept. 18 | Sunny | 30° /12° | 0 mm | 7 | |
| Sept. 19 | Sunny | 21° /13° | 0 mm | 6 | |
| Sept. 20 | Overcast | 19° /11° | 0 mm | 5 | |
| Sept. 21 | Sunny | 20° /10° | 0 mm | 5 | |
| Sept. 22 | Overcast | 17° /7° | 0 mm | 5 | |
| Sept. 23 | Sunny | 19° /6° | 0 mm | 5 | |
| Sept. 24 | Sunny | 20° /6° | 0 mm | 6 | |
| Sept. 25 |  Moderate or heavy rain shower | 18° /11° | 4.8 mm | 4 | |
| Sept. 26 |  Heavy rain at times | 17° /8° | 2.9 mm | 4 | |
| Sept. 27 | Overcast | 22° /12° | 0 mm | 5 | |
| Sept. 28 | Overcast | 18° /11° | 0 mm | 4 | |
| Sept. 29 | Partly cloudy | 17° /11° | 11.2 mm | 5 | |
| Sept. 30 | Overcast | 18° /10° | 8.9 mm | 4 | |
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Olympia in September - FAQ
What are the expected maximum and minimum temperatures in Olympia during September?
How much rainfall should be expected in Olympia during September?
What are the typical wind conditions in Olympia during September?
September rainfall patterns in Olympia
UV exposure in Olympia during September
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Where is Olympia?Get accurate weather forecasts for Olympia, located at latitude 47.038 and longitude -122.901. Stay updated with localized weather information tailored for Olympia.