Typical August weather
Chicago
Illinois · August
83° days
65° nights
about 7 rainy days · 14 hours of daylight · lake 73°
What to pack
- Swimsuit
- Sunscreen
What August feels like
Lollapalooza swallows Grant Park early in the month and the Air and Water Show packs the beaches later. This is the one stretch when the water is warm enough that swimming feels like a plan rather than a dare.
Expect about 7 days with real rain — enough to notice, not enough to plan around. There’s a little humidity in the air, but nothing that changes your plans.
Can you swim?
The lake runs about 73° — comfortable for swimming.
The numbers
| Typical high | 83° |
|---|---|
| Typical low | 65° |
| Days with real rain | 7 |
| Total rain | 4.3 in |
| Humidity | a touch humid |
| Water temperature | 73° |
| Sunrise / sunset (mid-month) | 5:59 am / 7:50 pm |