Olympia (WA)
September
Weather in Olympia, Washington for September 2025
Your guide to Olympia weather in September - trends and predictions
In general, the average temperature in Olympia at the beginning of September is 29 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 18.9 °F by the end of September.
Olympia experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 33.2 mm.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
22
Dry days
8
Rainy days
0
Snow days
22°/11°
Temperatures
10 km/h
Avg max wind
76 %
Avg humidity
Olympia Weather September
Move between months or click on a day
Temperatures trend during September in Olympia
See the weather trend as well as the moving average line
September weather in Olympia day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 31° /14° | 0 mm | 7 | |
| Sept. 2 | Overcast | 23° /12° | 0 mm | 5 | |
| Sept. 3 | Overcast | 24° /14° | 0 mm | 5 | |
| Sept. 4 | Overcast | 28° /11° | 0 mm | 6 | |
| Sept. 5 |  Sunny | 33° /13° | 0 mm | 8 | |
| Sept. 6 | Sunny | 33° /14° | 0 mm | 8 | |
| Sept. 7 |  Partly cloudy | 31° /15° | 0 mm | 8 | |
| Sept. 8 | Sunny | 27° /12° | 0 mm | 7 | |
| Sept. 9 | Overcast | 23° /12° | 0 mm | 5 | |
| Sept. 10 | Overcast | 21° /9° | 1.1 mm | 5 | |
| Sept. 11 |  Moderate rain at times | 16° /10° | 11 mm | 4 | |
| Sept. 12 |  Patchy rain possible | 19° /11° | 1.4 mm | 4 | |
| Sept. 13 | Moderate rain at times | 20° /8° | 1.2 mm | 5 | |
| Sept. 14 |  Heavy rain at times | 19° /10° | 2 mm | 4 | |
| Sept. 15 | Patchy rain possible | 19° /9° | 0.8 mm | 4 | |
| Sept. 16 | Overcast | 22° /8° | 0 mm | 5 | |
| Sept. 17 | Overcast | 16° /11° | 0 mm | 4 | |
| Sept. 18 | Patchy rain possible | 18° /12° | 0.1 mm | 4 | |
| Sept. 19 | Patchy rain possible | 17° /12° | 0.1 mm | 4 | |
| Sept. 20 | Overcast | 18° /10° | 0 mm | 4 | |
| Sept. 21 |  Cloudy | 19° /9° | 0 mm | 4 | |
| Sept. 22 | Overcast | 19° /10° | 0 mm | 4 | |
| Sept. 23 | Patchy rain possible | 21° /15° | 0.1 mm | 5 | |
| Sept. 24 | Cloudy | 26° /15° | 0 mm | 6 | |
| Sept. 25 | Moderate or heavy rain shower | 19° /13° | 9.6 mm | 4 | |
| Sept. 26 | Heavy rain at times | 17° /10° | 5.8 mm | 4 | |
| Sept. 27 | Overcast | 19° /12° | 0 mm | 4 | |
| Sept. 28 | Overcast | 17° /9° | 0 mm | 4 | |
| Sept. 29 | Partly cloudy | 17° /8° | 0 mm | 5 | |
| Sept. 30 | Overcast | 17° /9° | 0 mm | 4 | |
| Next | |||||
Important Notice
Our weather forecast for Olympia in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Olympia forecast closer to your planned date for the most up-to-date weather information.
Change Month
Olympia in September - FAQ
What are the expected maximum and minimum temperatures in Olympia during September?
Enjoy moderate daytime temperatures of up to 22° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Olympia during September?
In September, Olympia can expect light to moderate rainfall, totaling 33.2 mm across approximately 8 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in Olympia during September?
The average wind speed in Olympia during September is 10 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Olympia
Explore the daily rainfall trends and prepare for Olympias September weather 💧
UV exposure in Olympia during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Quick links
More Olympia weather pages
You are here
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.
Found a mistake?
We appreciate your attention to details. Tell us here.