United StatesAverage weather for Illinois in July
It's warm in July in Illinois with an average temperature of 29°C. Temperatures this month range from a low of 27°C to a high of 31°C. At night, you can expect temperatures between 18°C and 21°C.
Start of July
The month of July starts in Illinois with hot temps, averaging around 30°C during the day and nights around 20°C. You can expect regular precipitation, but there will also be some sunny days in the early part of the month.
With the temperature difference between day and night, it’s smart to wear layers.
Mid July
By mid-July, daytime temps stay steady at around 30°C, with nights around 21°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of July
By the end of July, the average daytime temperature in Illinois is around 30°C, while nighttime temps are about 20°C. A shower might pop up, but overall, the weather will be dry and sunny.
Because temperatures drop in the evening, wearing layers is recommended.
In July, there is an average of 96 mm of precipitation, spread over 10 days. The wind speed is around 3 Bft, mostly coming from the South.
Illinois in July |
New York | ||
|---|---|---|---|
 Average temperature |
29°C | 31°C | |
 Max. temperature |
31°C | 33°C | |
| Min. temperature |
27°C | -5°C | |
 Total precipitation |
96 mm | 160 mm | |
| Rainy days |
10 days | 18 days | |
June
UV index
The UV index is a maximum of 3 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Is July a good time to visit Illinois?
Looking for great weather? July is a good time to be in Illinois. The temperatures are nice, and there’s not too much rain.
Temperature records
With 37°C in 2022, Illinois reached the highest temperature in July over the past 10 years. The lowest daytime temperature in this month was 16°C in 2015. The extreme nighttime temperatures ranged from a lowest recorded value of 12°C to a highest value of 26°C.
Check out the climate of Illinois for all months and discover the best travel time
The climate in Illinois is based on weather data from . Other places, like New York City, Miami or Los Angeles, might have different weather. You can check out all destinations in Illinois to get the full picture of the climate.
Daily Temperature in July in Illinois
This chart shows the average daily high and low temperatures in July for Illinois, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for this month.
Daily Precipitation in July in Illinois
The chart below shows the average daily precipitation in July for Illinois, measured in millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for July, you can expect about 10 days of precipitation in Illinois.
Daily UV index in July in Illinois
This chart shows the average daily UV index in July in Illinois, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in July in Illinois over the years
This chart shows the average temperature in July in Illinois, measured in degrees Celsius, over the past few years.
Total precipitation in July in Illinois over the years
This chart shows the average precipitation in July in Illinois, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Daily weather in July for Illinois
Click on any day in July to get detailed info about the usual weather on that day in Illinois. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in July in Illinois
Have you been to Illinois in July?
Share your weather experience in July in Illinois.
Average weather in Illinois by month
Click on a month below to see detailed weather info for Illinois. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
