Rio Grande City Weather in September

What's the weather like in Rio Grande City (Texas) in September 2025?

The climate in Rio Grande City during September can be summarized as hot, humid and damp.

September is in the fall / autumn in Rio Grande City and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a steamy 34°C (93°F), whilst at night 22°C (71°F) is normal.

Rio Grande City weather averages (imperial / metric)
Daytime temperature 34°C 93.1°F
Nightly temperature 21.9°C 71.3°F
Average temperature 27.9°C 82.2°F
Daily sunshine 7.2 hrs
Avg rainfall 110 mm 4.3 ins
Rainy days 6 days
Sea temperature 28.9°C 84°F
Humidity 71%
Windspeed 13.7kph 9 mph

On average September is the wettest month of the year in Rio Grande City with around 110mm 4.3 inches of rain making it a damp time to visit. This rainfall is typically spread over 6 days, although this may vary considerably.

On the flip side this corresponds to an average of 7.2 hours of sunshine per day.

September temperatures in Rio Grande City

Rio Grande City average temperature in September

September rainfall

Rio Grande City average rain in September

September hourly sunshine

Rio Grande City 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 Rio Grande City in September 2025.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Rio Grande City weather stats

Rio Grande City weather statistics
Hottest month: July 36.4°C 97.5°F
Driest month: March 15mm 0.6ins
Sunniest month: July 9.4hrs
Coldest month: January 19.5°C 67.1°F
Wettest month: September 110mm 4.3ins
Map showing location of Rio Grande City (26.37979, -98.8203) Rio Grande City map pin © Google

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