St. Louis weather in August
Temperature, rain and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Good
Best time to visit: April – May, September – October
What is the weather like in St. Louis in August?
In August, St. Louis is hot: daytime highs average 30 °C, and even at night it stays warm at around 21 °C. The sun shines for around 8 hours a day. Rain is frequent, with about 9 rainy days and 77 mm in total. On about 17 days the thermometer climbs to 30 °C or more. The air is often humid and muggy. All in all, August is a good month for a holiday in St. Louis.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 59 | 65 | 86 |
| Day | 31° | 30° | 27° |
| Night | 22° | 21° | 17° |
| Sun | 9 h | 8 h | 7 h |
| Rain days | 10 | 9 | 7 |
More details for August
- Daylight
- 13 h 43 min06:14 – 19:57
- UV index
- 9 · very highclear sky, noon (estimate)All months
- Muggy days
- 19 daysdew point 18 °C or moreAll months
- Wind
- 13 km/haverage daily peakAll months
- Cloud cover
- 48 %on averageAll months
- Hot days
- 17 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC−5America/Chicago
How the score comes together
- Temperatureweight 50 %58 %
- Sunshineweight 20 %83 %
- Few rainy daysweight 30 %64 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in August
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Water bottle – drink plenty
- Insect repellent
- Rain jacket or umbrella
St. Louis in August: quick answers
Is St. Louis hot in August?
Yes. In August, St. Louis is hot: daytime highs average 30 °C and nights stay around 21 °C. On about 17 days the thermometer climbs to 30 °C or more.
Does it rain much in St. Louis in August?
Rain is frequent, with about 9 rainy days and 77 mm in total.
St. Louis month by month
The whole year in St. LouisAll destinations: USAWhere to go in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences