St. Louis, MO weather in May
May in St. Louis: mild, with frequent rain. Highs 77°F, lows 58°F, about 13 days with rain.
- Normal high
- 77°F
- Normal low
- 58°F
- Wet days
- 13
- 4.8 in total
- Muggy days
- 4
- dew point 65°F+
How May changes from start to finish
| May 1 | May 31 | |
|---|---|---|
| Normal high | 73°F | 82°F |
| Normal low | 53°F | 63°F |
| Chance of a wet day | 42% | 37% |
| Sunrise / sunset | 6:03 am / 7:52 pm | 5:38 am / 8:18 pm |
| Daylight | 13.8 h | 14.7 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 May day
- 6 am61°Fdew point 54°F
- 9 am68°Fdew point 55°F
- Noon73°Fdew point 55°F
- 3 pm75°Fdew point 54°F
- 6 pm73°Fdew point 54°F
- 9 pm68°Fdew point 55°F
NOAA hourly normals (local standard time) from St Louis Lambert Intl Airport (13 mi away); average wind 9 mph; clear or few clouds in 21% of daytime hours, mostly cloudy or overcast in 60%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F12 of 31
- Hot dayshigh 90°F or more2 of 31
- Muggy daysdaily mean dew point 65°F or more4 of 31
- Wet daysat least 0.01 in of rain or melted snow13 of 31
- Notable rainat least 0.10 in8 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per May, counted from daily records for each year 1991-2020.
Rain in May
Normal precipitation is 4.8 in; a dry May brings about 3.2 in and a wet one about 5.8 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How May varies from year to year
- Warmest May, 1991-20202018: average high 85°F
- Coolest May1997: average high 72°F
- Wettest May1995: 12.9 in
- Driest May2005: 0.8 in
- Highest reading96°F (May 27, 2018)
- Lowest reading38°F (May 4, 2011)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
May compared with April and June
| April | May | June | |
|---|---|---|---|
| Normal high | 68°F | 77°F | 86°F |
| Normal low | 47°F | 58°F | 67°F |
| Wet days | 12 | 13 | 10 |
| Comfortable days | 13 | 12 | 4 |
| Daylight | 13.2 h | 14.3 h | 14.8 h |
Highs change by +9°F from April and +9°F into June.
Nearby alternatives in May
- Cooler: Joliet, IL229 mi · high 71°F · 12 wet days
How St. Louis ranks in May
- Normal high168th warmest of 378 cities; 2nd of 7 in Missouri
- Wet days313th driest of 378
- Comfortable days182nd most of 339
What to pack for St. Louis in May
- A rain jacket or umbrella – rain on about 13 days
- Sunglasses and sunscreen – about 14.3 hours of daylight and highs near 77°F
Heating and cooling
May has 72 heating degree days and 150 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is St. Louis in May?
The normal high is 77°F and the normal low is 58°F. From 1991 to 2020 the hottest May reading was 96°F (May 27, 2018).
Does it rain a lot in St. Louis in May?
About 13 days in May have at least 0.01 in of precipitation, and the normal total is 4.8 in. The wettest May in 1991-2020 was in 1995 (12.9 in); the driest was in 2005 (0.8 in).
Is May a good time to visit St. Louis?
May ranks 2nd of 12 months on our comfort score for St. Louis (66 out of 100). It has about 12 comfortable days and about 2 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.