Humid cities · Missouri
How humid is St. Louis in summer?
Across June, July and August, the dew point in St. Louis averages about 65.1°F, which is muggy on the usual dew point scale.
July is the muggiest month, with the dew point averaging about 66.8°F. On NOAA’s hour by hour normals, about 1,484 hours, about 17% of the year, average a dew point of 65°F or more. That makes it the 36th most humid summer of the 124 US cities we track.
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The highest dew point in the forecast for the next 48 hours is about 36°F, which is dry.
St. Louis averages a summer dew point of about 65°F, and July reaches about 66.8. The Arch is the only thing here that stays dry.
Live 48-hour forecast from OpenWeatherMap, refreshed about every half hour. Alerts from the National Weather Service.
Summer humidity at a glance
| Dew point, June to August | 65.1°F |
|---|---|
| Muggiest month | July, 66.8°F |
| Hours a year at a 65°F dew point or more | 1,484 (17%) |
| How summer feels | muggy |
The dew point is the temperature the air would have to cool to for dew to form, so the higher it is, the more water the air holds. Forecasters usually call under 55°F comfortable, 55 to 65°F sticky and 65°F or more muggy; 70°F or more feels tropical.
Cities with about the same summer air
- Louisville, Kentucky: about 65.2°F
- Washington, DC: about 64.8°F
- Springfield, Missouri: about 65.4°F
More about the weather here
Source: NOAA U.S. Climate Normals, hourly, 1991 to 2020, station USW00013994. Average dew points, not the stickiest days.