St. Charles Weather in August

St. Charles in August averages 31°C (88°F) during the day and 20°C (68°F) at night. Keep in mind that quite a bit of rainfall is expected this month.

Rainfall in St. Charles in August

Records from the past 30 years suggest around 9 days of rain, with 92 mm (3.6 in) average for the month. The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.

Temperature in St. Charles in August

St. Charles in August gets highs of 31°C (88°F) during the day and drops to 20°C (68°F) at night. It's usually most comfortable outside during the morning and later in the day. With overnight lows of 20°C (68°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep.

Sunshine in St. Charles in August

Enjoy a sunny month with about 268 hours of sunshine, the clear skies make St. Charles even more beautiful.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. September and October typically offer the best weather for St. Charles.

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For a detailed overview over the year and the best time to visit the United States of America, check out our St. Charles's climate page.

St. Charles Temperature in August

Min Temperature 20°C (68°F)  

Max Temperature 31°C (88°F)  

Chance of Rain 28%  

Precipitation 92 mm (3.6 in)  

Rainy days 9 days  

Humidity 70% *  

Sunshine 268 hours *  

Percentage Sunshine 64% *  

* Data from: St. Louis, the United States of America (30 KM, 18 Miles).

What to Wear in St. Charles in August

Warm weather calls for comfortable, breathable clothing in August. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). High rain levels are expected, so pack waterproof gear and an umbrella or poncho. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in St. Charles in August

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

9/10

Cycling

7/10

Walking

7/10

Camping

8/10

Outdoor sports

7/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our St. Charles's climate page.

More climate data for St. Charles

Temperature Rainfall Sunshine Humidity

See the full St. Charles climate overview or explore weather in the United States of America.