St. Louis, MO weather in July
St. Louis is hot and oppressively humid in July, with some rain: highs average 90°F and nights drop to about 71°F. Rain falls on about 9 days. This is the peak of the warm season in St. Louis.
- Normal high
- 90°F
- Normal low
- 71°F
- Wet days
- 9
- 3.9 in total
- Muggy days
- 21
- dew point 65°F+
How July changes from start to finish
| July 1 | July 31 | |
|---|---|---|
| Normal high | 89°F | 90°F |
| Normal low | 70°F | 71°F |
| Chance of a wet day | 30% | 28% |
| Sunrise / sunset | 5:40 am / 8:29 pm | 6:01 am / 8:12 pm |
| Daylight | 14.8 h | 14.2 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Central Time).
A typical July day
- 6 am74°Fdew point 67°F
- 9 am81°Fdew point 67°F
- Noon86°Fdew point 67°F
- 3 pm88°Fdew point 66°F
- 6 pm85°Fdew point 66°F
- 9 pm80°Fdew point 67°F
NOAA hourly normals (local standard time) from St Louis Lambert Intl Airport (13 mi away); average wind 8 mph; clear or few clouds in 25% of daytime hours, mostly cloudy or overcast in 44%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F1 of 31
- Hot dayshigh 90°F or more16 of 31
- Muggy daysdaily mean dew point 65°F or more21 of 31
- Wet daysat least 0.01 in of rain or melted snow9 of 31
- Notable rainat least 0.10 in6 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per July, counted from daily records for each year 1991-2020.
Rain in July
Normal precipitation is 3.9 in; a dry July brings about 2.2 in and a wet one about 5.4 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How July varies from year to year
- Warmest July, 1991-20202012: average high 99°F
- Coolest July2009: average high 84°F
- Wettest July2020: 9.1 in
- Driest July2012: 0.7 in
- Highest reading108°F (July 22, 2017)
- Lowest reading56°F (July 28, 2013)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
July compared with June and August
| June | July | August | |
|---|---|---|---|
| Normal high | 86°F | 90°F | 88°F |
| Normal low | 67°F | 71°F | 69°F |
| Wet days | 10 | 9 | 8 |
| Comfortable days | 4 | 1 | 2 |
| Daylight | 14.8 h | 14.6 h | 13.6 h |
Highs change by +4°F from June and -2°F into August.
Nearby alternatives in July
- Cooler: Joliet, IL229 mi · high 84°F · 9 wet days
How St. Louis ranks in July
- Normal high154th warmest of 378 cities; 4th of 7 in Missouri
- Wet days173rd driest of 378
- Comfortable days183rd most of 340
What to pack for St. Louis in July
- Light, breathable clothing – highs near 90°F and about 21 muggy days
- A rain jacket or umbrella – rain on about 9 days
- Sunglasses and sunscreen – about 14.6 hours of daylight and highs near 90°F
Heating and cooling
July has 0 heating degree days and 476 cooling degree days (base 65°F), 8% of the year's total heating and cooling demand.
Questions
How hot is St. Louis in July?
The normal high is 90°F and the normal low is 71°F. From 1991 to 2020 the hottest July reading was 108°F (most recently on July 22, 2017).
Does it rain a lot in St. Louis in July?
About 9 days in July have at least 0.01 in of precipitation, and the normal total is 3.9 in. The wettest July in 1991-2020 was in 2020 (9.1 in); the driest was in 2012 (0.7 in).
Is July a good time to visit St. Louis?
July ranks 9th of 12 months on our comfort score for St. Louis (45 out of 100). It has about 1 comfortable day and about 16 days at 90°F or hotter. The best months are April and May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth, humidity and wind by hour and cloud cover: St Louis Lambert Intl Airport (USW00013994), 13 mi NW of the city center, 531 ft (67 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Frost dates: Cahokia St Louis Airport (USW00003960), 4.4 mi SSE of the city center, 413 ft (51 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Lambert-St Louis International Airport (724340-13994), 13 mi NW of the city center, 531 ft (67 ft higher than the city). Hourly observations, 1991-2020.