Click on a day for an hourly weather forecast
The temperatures in Joliet in August are comfortable with low of 18°C and and high up to 27°C.
You can expect rain for roughly half of the month of August in Joliet. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Joliet in August 2025.
If you’re planning to visit Joliet in the near future, we highly recommend that you review the 14 day weather forecast for Joliet before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -2° / -8° | 4 | 12 | 15 | 81 mm | Awful | Joliet in January |
| February | 0° / -7° | 4 | 11 | 13 | 85 mm | Awful | Joliet in February |
| March | 8° / 1° | 8 | 17 | 7 | 111 mm | Awful | Joliet in March |
| April | 14° / 5° | 8 | 19 | 2 | 154 mm | Bad | Joliet in April |
| May | 21° / 12° | 10 | 21 | 0 | 199 mm | Ok | Joliet in May |
| June | 26° / 17° | 10 | 20 | 0 | 220 mm | Good | Joliet in June |
| July | 27° / 19° | 9 | 22 | 0 | 177 mm | Good | Joliet in July |
| August | 27° / 18° | 8 | 23 | 0 | 154 mm | Good | Joliet in August |
| September | 24° / 14° | 6 | 24 | 0 | 116 mm | Perfect | Joliet in September |
| October | 16° / 8° | 7 | 24 | 0 | 134 mm | Ok | Joliet in October |
| November | 8° / 2° | 5 | 21 | 4 | 79 mm | Bad | Joliet in November |
| December | 2° / -3° | 5 | 16 | 10 | 78 mm | Awful | Joliet in December |