San Luis Obispo (CA)
September
Weather in San Luis Obispo, California for September 2026
Your guide to San Luis Obispo weather in September - trends and predictions
So far, September 2026 in San Luis Obispo is slightly warmer than the historical average by 0.6 °F.
The forecast for the upcoming days in San Luis Obispo predicts a temperature of 24.6 °F, which is slightly above the historical average.
In general, the average temperature in San Luis Obispo at the beginning of September is 27.4 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 24.3 °F by the end of September.
With an average of 3 rainy days, San Luis Obispo experiences minimal rainfall in September.
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Temperatures
Rain 🌧️
More
27
Dry days
3
Rainy days
0
Snow days
25°/13°
Temperatures
13 km/h
Avg max wind
68 %
Avg humidity
San Luis Obispo Weather September
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Temperatures trend during September in San Luis Obispo
See the weather trend as well as the moving average line
September weather in San Luis Obispo day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 26° /13° | 0 mm | 8 | |
| Sept. 2 | Sunny | 26° /13° | 0 mm | 8 | |
| Sept. 3 | Sunny | 27° /14° | 0 mm | 8 | |
| Sept. 4 | Sunny | 26° /14° | 0.4 mm | 6 | |
| Sept. 5 | Sunny | 29° /15° | 0 mm | 8 | |
| Sept. 6 | Sunny | 28° /14° | 0 mm | 8 | |
| Sept. 7 | Sunny | 30° /14° | 0 mm | 8 | |
| Sept. 8 | Sunny | 29° /14° | 0 mm | 5 | |
| Sept. 9 | Sunny | 30° /15° | 0 mm | 7 | |
| Sept. 10 | Sunny | 27° /14° | 0 mm | 7 | |
| Sept. 11 | Sunny | 25° /12° | 0 mm | 7 | |
| Sept. 12 | Sunny | 25° /12° | 0 mm | 6 | |
| Sept. 13 | Sunny | 24° /12° | 0 mm | 6 | |
| Sept. 14 | Sunny | 27° /13° | 0 mm | 7 | |
| Sept. 15 |  Partly cloudy | 23° /13° | 0 mm | 6 | |
| Sept. 16 | Partly cloudy | 22° /13° | 0 mm | 6 | |
| Sept. 17 |  Mist | 25° /13° | 0 mm | 7 | |
| Sept. 18 | Mist | 22° /13° | 2.4 mm | 6 | |
| Sept. 19 | Mist | 22° /13° | 0 mm | 6 | |
| Sept. 20 |  Thundery outbreaks possible | 22° /12° | 0 mm | 4 | |
| Sept. 21 | Sunny | 19° /14° | 0.2 mm | 7 | |
| Sept. 22 | Sunny | 20° /13° | 0 mm | 7.2 | |
| Sept. 23 | Sunny | 25° /17° | 0 mm | 7.1 | |
| Sept. 24 | Sunny | 24° /18° | 0 mm | 7.1 | |
| Sept. 25 | Sunny | 25° /17° | 0 mm | 7 | |
| Sept. 26 |  Overcast | 22° /15° | 0 mm | 6 | |
| Sept. 27 | Sunny | 21° /14° | 0 mm | 6 | |
| Sept. 28 | Sunny | 26° /15° | 0 mm | 7 | |
| Sept. 29 | Sunny | 28° /18° | 0 mm | 7 | |
| Sept. 30 | Sunny | 24° /18° | 0 mm | 6 | |
| Next | |||||
Important Notice
Our weather forecast for San Luis Obispo 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 San Luis Obispo forecast closer to your planned date for the most up-to-date weather information.
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San Luis Obispo in September - FAQ
What are the expected maximum and minimum temperatures in San Luis Obispo during September?
Enjoy moderate daytime temperatures of up to 25° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in San Luis Obispo during September?
In September, San Luis Obispo can expect light to moderate rainfall, totaling 20.4 mm across approximately 3 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in San Luis Obispo during September?
The average wind speed in San Luis Obispo during September is 13 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in San Luis Obispo
Explore the daily rainfall trends and prepare for San Luis Obispos September weather 💧
Typically, San Luis Obispo has 3 rainy days in September with a total of 20.4 mm of rainfall.
UV exposure in San Luis Obispo during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is San Luis Obispo?Get accurate weather forecasts for San Luis Obispo, located at latitude 35.283 and longitude -120.66. Stay updated with localized weather information tailored for San Luis Obispo.
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