Normal weather for Illinois in August
It's warm in August 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 17°C and 20°C.
In August, there is an average of 92 mm of precipitation, spread over 12 days. The wind speed is around 3 Bft, mostly coming from the South.
Illinois in August |
New York | ||
|---|---|---|---|
 Average Temperature |
29°C | 30°C | |
 High Temp |
31°C | 31°C | |
| Low Temp |
27°C | 28°C | |
 Total Precipitation |
92 mm | 79 mm | |
| Rainy Days |
12 days | 13 days | |
Start of August
The month of August starts in Illinois with hot temps, averaging around 29°C during the day and nights around 19°C. A few showers might pop up early in the month, but overall, it’ll stay mostly sunny and dry.
With the temperature difference between day and night, it’s smart to wear layers. For the daytime, light clothing like shorts or a dress, and a hat and sunglasses are perfect. In the evening and morning, a T-shirt, light pants or skirt, and a light jacket are ideal.
Mid August
By mid-August, daytime temps stay steady at around 29°C, with nights around 19°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
Since it cools down at night, it’s a good idea to wear layers. For the daytime, light clothing like shorts or a dress, and a hat and sunglasses are perfect. In the evening and morning, a T-shirt, light pants or skirt, and a light jacket are ideal.
End of August
By the end of August, the average daytime temperature in Illinois is around 29°C, while nighttime temps are about 19°C. Expect regular precipitation, but if you’re lucky, you’ll also get some dry and sunny days.
Because temperatures drop in the evening, wearing layers is recommended. For the daytime, light clothing like shorts or a dress, and a hat and sunglasses are perfect. In the evening and morning, a T-shirt, light pants or skirt, and a light jacket are ideal.
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UV index
The UV index is a maximum of 2 this month. That's a low value on the intensity scale of 1 to 11. The risk of sunburn is minimal at this time.
Is August a good time to visit Illinois?
Looking for great weather? August is a good time to be in Illinois. The temperatures are nice, and there’s not too much rain.
Temperature records for Illinois in August
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.
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Daily Temperature in August in Illinois
This chart shows the average daily high and low temperatures in August 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 August in Illinois
The chart below shows the average daily precipitation in August 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 August, you can expect about 12 days of precipitation in Illinois.
Daily UV Index in August in Illinois
This chart shows the average daily UV index in August 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 August in Illinois Over the Years
This chart shows the average temperature in August in Illinois, measured in degrees Celsius, over the past few years.
Total Precipitation in August in Illinois Over the Years
This chart shows the average precipitation in August in Illinois, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Daily Climate in August for Illinois
Click on any day in August 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 August in Illinois
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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.
