St. Louis, Missouri Weather
Fireflies pulse through the magnolias. Day 78 of spring. Read this microseason across nine climate regions →
St. Louis weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——85°60°—
- FridayJun 5Overcast11%—90°67°+5°
- SaturdayJun 6Heavy Drizzle20%0.09″88°67°-2°
- SundayJun 7Drizzle53%0.01″87°71°-1°
- MondayJun 8Showers65%0.01″90°69°+3°
- TuesdayJun 9Showers43%0.01″98°72°+8°
- WednesdayJun 10Clear15%—99°77°+1°
Ozone at AQI 500. AQI up 34 in the last 6 hours — air quality is degrading. Overcast through the UV peak window (cloud cover ~70%) — afternoon ozone should stay flat.
AVOID OUTDOORS Avoid outdoor exertion. Keep windows closed; use HEPA filtration indoors if available.
What's driving it
Ozone × UV × Sky
Ozone at AQI 500. Overcast through the UV peak window (cloud cover ~70%) — afternoon ozone should stay flat.
- Present
- AQI 500
- UV peak
- 0.0 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 60
PM × Wind × Precip
PM2.5 at 10.3 µg/m³, PM10 at 11.9 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.87
- Wind
- breezy
- Recent rain
- 0h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
The higher the clouds, the finer the weather.
- Moonrise
- 4:57 AM
- Moonset
- 3:11 PM
- In sign
- ♒︎ Aquarius
Fireflies pulse through the magnolias
St. Louis at a glance
- Today vs. normal: 4°F above the seasonal normal for this latitude
- Last frost: April 8 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — St. Louis
SPC has placed St. Louis in the General Thunderstorms category for severe thunderstorms tomorrow.
- TODAYNONENo severe risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
July brings St. Louis its warmest temperatures at around 81°F mean, while January delivers the coldest at approximately 33°F. Precipitation follows its own pattern, with May receiving the most rainfall at 4.9 inches and February getting the least at 2.3 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 33° | 2.7″ | 9 |
| February | 37° | 2.3″ | 8 |
| March | 47° | 3.6″ | 12 |
| April | 58° | 4.8″ | 16 |
| May | 68° | 4.9″ | 16 |
| June | 77° | 4.7″ | 16 |
| July | 81° | 4.2″ | 14 |
| August | 79° | 3.8″ | 13 |
| September | 72° | 3.4″ | 11 |
| October | 60° | 3.2″ | 11 |
| November | 48° | 3.7″ | 12 |
| December | 37° | 2.6″ | 9 |
Regional context
St. Louis belongs to the humid subtropical climate region, sharing temperature ranges, seasonal patterns, and growing conditions with other nearby cities in this zone.
Similar climates: Kansas City, MO, Springfield, MO, Columbia, MO, Independence, MO, Lee's Summit, MO.
Naturalist notes
Late May brings the peak blooming period for native elderberry shrubs throughout the St. Louis area.
Ruby-throated hummingbirds typically arrive in St. Louis during the first week of May as spring migration reaches its peak.
Frequently asked
- When does it freeze in St. Louis?
- Spring's last frost usually occurs around mid-April in St. Louis, while the first fall frost typically arrives around mid-November.
- What is the rainy season in St. Louis?
- May stands as the wettest month, averaging about 4.9 inches of rain, while the city receives roughly 44 inches total each year.
- What is the warmest month in St. Louis?
- July typically brings the warmest temperatures, averaging about 81°F.
- What is the coldest month in St. Louis?
- January usually delivers the coldest weather, averaging about 33°F.
- When can I start a vegetable garden in St. Louis?
- Cool-season crops like peas and lettuce can go in the ground around the last spring frost in mid-April, but warm-season crops such as tomatoes and peppers should wait 1–2 weeks after that date.
- How many rainy days does St. Louis get?
- St. Louis sees approximately 147 rainy days per year on average.
- What hardiness zone is St. Louis?
- St. Louis's USDA hardiness zone depends on its lowest average winter temperature; the USDA's online lookup tool can provide the current zone designation using the city ZIP code.
Climate
St. Louis, Missouri experiences a humid subtropical climate zone. Temperatures hover near 33°F in January while July averages 81°F, creating a 48°F seasonal swing.
Annual precipitation totals about 44 inches across roughly 147 rainy days throughout the year.
Several factors combine to shape the local climate: latitude at 38.6°N, proximity to large water bodies, and elevation. These elements determine growing patterns, frost timing, and daily weather conditions.