Greenville (IL) Weather & Climate: Best Time to Visit

The climate in Greenville is known for significant temperature differences throughout the year, making the weather dynamic. On average, daytime temperatures range from a very warm 31°C (88°F) in July to a chilly 3°C (37°F) in January.

Nighttime temperatures range from 19°C (66°F) in July to -6°C (21°F) in January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Greenville has a notably wet climate with abundant precipitation, recording 1147 mm (45 in) of rain/snowfall per year. The seasons in Greenville bring significant changes in precipitation. The wettest month, June, receives high rainfall, with an average of 138 mm (5.4 in) of precipitation. This rainfall is distributed across 13 rainy days.

In contrast, the driest month, January, experiences much less snow/rainfall, totaling 58 mm (2.3 in) over 8 snowy/rainy days. These distinct seasonal differences provide diverse experiences throughout the year. For more details, please visit our Greenville Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

In Greenville, summer days are longer and more sunny, with daily sunshine hours peaking at 10.4 hours in July. As the darker season arrives, the brightness of the sun becomes less. December sees a soft sun for only 4.3 hours per average day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The relative humidity is high throughout the year in Greenville.

The city experiences its highest humidity in December, reaching 74%. In April, the humidity drops to its lowest level at 63%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year