San Luis Weather in September

What's the weather like in San Luis (Colorado) in September 2025?

The climate in San Luis during September can be summarized as mild and reasonably dry.

September is in the fall / autumn in San Luis and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 21°C (70°F), whilst at night 3°C (36°F) is normal.

San Luis weather averages (imperial / metric)
Daytime temperature 21°C 69.7°F
Nightly temperature 2.5°C 36.4°F
Average temperature 11.7°C 53.1°F
Daily sunshine 9.8 hrs
Avg rainfall 32 mm 1.3 ins
Rainy days 7 days
Sea temperature 19.3°C 66.7°F
Humidity 50%
Windspeed 16.2kph 10 mph

On average September is the 4th wettest month of the year in San Luis with around 32mm 1.3 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 7 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.8 hours of sunshine per day.

September temperatures in San Luis

San Luis average temperature in September

September rainfall

San Luis average rain in September

September hourly sunshine

San Luis average rain in September

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in San Luis in September 2025.

Other monthly averages

Best places to visit in September

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Beta

Current (hourly) weather 15 day forecast

San Luis weather stats

San Luis weather statistics
Hottest month: July 25.4°C 77.7°F
Driest month: January 14mm 0.6ins
Sunniest month: October 9.3hrs
Coldest month: January 1.8°C 35.2°F
Wettest month: August 57mm 2.2ins
Map showing location of San Luis (37.20085, -105.4239) San Luis map pin © Google

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