Deerfield (IL) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Deerfield.
Climate overview of Deerfield
Temperatures in Deerfield, Illinois, United States of America, vary greatly throughout the year. July is the hottest month at 29°C (84°F), while January is the coldest at 0°C (32°F).
Rain/snowfall is high, totalling around 1028 mm (40 in) per year. August is the wettest month and January the driest. The city also experiences warm summers and very cold winters. Sunshine peaks in July, when the city sees around 10.6 hours of sunshine per day.
Deerfield Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Deerfield - and find the best time to visit.
Monthly Temperature in Deerfield
The climate in Deerfield is known for significant temperature differences throughout the year, making the weather dynamic. Average maximum daytime temperatures range from a comfortable 29°C (84°F) in July, the warmest time of the year, to a very cold 0°C (32°F) during cooler months like January.
At night, you can expect temperatures ranging from 18°C (64°F) in July to around -9°C (16°F) during January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Deerfield
Deerfield has a notably wet climate with abundant precipitation, recording 1028 mm (40 in) of rain/snowfall per year. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, August it receives high rainfall, averaging 116 mm (4.6 in) of precipitation, recorded across 11 rainy days. In contrast, the driest month January brings less snowfall, with 48 mm (1.9 in) over 11 snowy days. For more details, please visit our Deerfield Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Deerfield
Seasonal changes in sunshine hours are quite dramatic in Deerfield. While July receives considerable daily sunshine with up to 10.6 hours, December marks the darkest time of the year, where sunshine is scarce with only 3.6 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Deerfield by Month
The relative humidity is high throughout the year in Deerfield.
The city experiences its highest humidity in December, reaching 76%. In May, the humidity drops to its lowest level at 64%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in Deerfield
The mean wind speed over the year ranges from 4 m/s (8 knots) in June, July, August and September to 6 m/s (12 knots) in January, March and April. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit Deerfield
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: September
- Warmest weather: July and August
- Most sunshine: June and July
- Fewest rainy days: February, March, September and November
- Seasonal pattern: Warm summers and very cold winters
- Coldest conditions: January, with freezing nights around -9°C (16°F).
Frequently asked questions about the climate in Deerfield
What is the best time to visit Deerfield?
September typically offers the most optimal weather in Deerfield. In contrast, January, February, March, November and December tend to have less optimal conditions. Deerfield has warm summers and very cold winters.
What temperatures can I expect in Deerfield?
Daytime highs range from 0°C (32°F) in January to 29°C (84°F) in July. Nighttime lows range from -9°C (16°F) to 18°C (64°F). Temperatures vary considerably through the year.
How much rain does Deerfield get?
Annual rainfall is around 1028 mm (40 in). August is the wettest month with 116 mm (4.6 in), while January is the driest with 48 mm (1.9 in).
How sunny is Deerfield?
Deerfield receives around 2,509 hours of sunshine per year. July is the sunniest month with 319 hours, while December is the cloudiest with just 107 hours. Overall, Deerfield enjoys abundant sunshine.
Deerfield 3-Day Forecast
Deerfield on the map
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Popular this month
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