Clayton, Missouri Weather
Cicadas claim the scorching afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Clayton weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Light Drizzle23%—93°77°—
- SundayJul 5Rain28%0.10″82°72°-11°
- MondayJul 6Overcast31%—87°70°+5°
- TuesdayJul 7Clear——89°69°+2°
- WednesdayJul 8Partly Cloudy11%—96°69°+7°
- ThursdayJul 9Overcast31%—100°77°+4°
- FridayJul 10Thunderstorm46%—99°81°-1°
AQI 48 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 11.9 µg/m³, PM10 at 13.1 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 50. Overcast through the UV peak window (cloud cover ~99%) — afternoon ozone should stay flat.
- Present
- AQI 50
- UV peak
- 5.7 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 19
PM × Wind × Precip
PM2.5 at 11.9 µg/m³, PM10 at 13.1 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.91
- Wind
- light
- 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).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 10:54 PM
- Moonset
- 10:09 AM
- In sign
- ♓︎ Pisces
Cicadas claim the scorching afternoon
Clayton at a glance
- Today vs. normal: 15°F above the seasonal normal for this latitude
- Last frost: April 8 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Clayton
- Sat93°77°23%
- Sun82°72°28%
- Mon87°70°31%
- Tue89°69°5%
- Wed96°69°11%
- Thu100°77°31%
- Fri99°81°46%
- Sat84°70°22%
- Sun83°65°7%
- Mon86°65°6%
- Tue84°65°10%
- Wed91°64°10%
- Thu94°69°10%
- Fri96°73°9%
- Sat82°68°14%
- Sun77°68°16%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 4, 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 — Clayton
SPC has placed Clayton in the Slight Risk category for severe thunderstorms today.
- TODAYSLGTSlight Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.
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.
Microseason · July 1–5
Cicadas claim the scorching afternoon
Dog-day cicadas emerge in waves, their rasp dominating every sunny hour; heat peaks above 90 degrees daily.
Day 185 of 365 · Wedge 37 of 72
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
In Clayton, July runs warmest near 81°F and January coldest around 31°F, while May is the wettest month (4.4 inches) and January the driest (2.1 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 31° | 2.1″ | 13 |
| February | 35° | 2.3″ | 12 |
| March | 45° | 4.0″ | 16 |
| April | 57° | 4.3″ | 15 |
| May | 66° | 4.4″ | 17 |
| June | 75° | 4.2″ | 15 |
| July | 81° | 2.7″ | 13 |
| August | 80° | 2.9″ | 13 |
| September | 72° | 2.6″ | 11 |
| October | 60° | 2.8″ | 11 |
| November | 45° | 3.6″ | 13 |
| December | 34° | 3.0″ | 12 |
Regional context
Clayton swings from 31°F in January to 81°F in July (50°F) per NOAA NCEI 1991-2020 normals; precipitation in Clayton runs about 39.1 inches on roughly 161 measurable days.
Rainfall in Clayton stays even across the calendar: May tops out at 4.4 inches over 17.2 rainy days, and January still logs 2.1 inches across 12.7 — a narrow range for Clayton. It is a balanced pattern Clayton shares with places like Richmond Heights, MO, University City, MO and Brentwood, MO.
Once Clayton passes mid-April, overnight freezes fade and peas, lettuce, spinach, and radishes can be sown. Clayton's heat-lovers — tomatoes, peppers, squash — hold off until Clayton's frost risk clears, 10-14 days on. By mid-November, frost is back in Clayton — protect or harvest anything tender. A creek-bottom lot in Clayton can lag Clayton's last frost 7-10 days behind a south slope.
Similar climates: Richmond Heights, MO, University City, MO, Brentwood, MO, Maplewood, MO, Pagedale, MO.
Frequently asked
- When does it freeze in Clayton?
- Frost typically leaves Clayton by mid-April and returns to Clayton near mid-November.
- What is the rainy season in Clayton?
- Rainfall in Clayton peaks in May near 4.4 inches, out of about 39 inches annually.
- What is the warmest month in Clayton?
- The warmest stretch in Clayton comes in July, around 81°F on average.
- What is the coldest month in Clayton?
- On average January is the chilliest month in Clayton, about 31°F.
- When can I start a vegetable garden in Clayton?
- Time tomatoes in Clayton for two weeks after mid-April; peas and greens start at Clayton's frost line.
- How many rainy days does Clayton get?
- Clayton records around 161 days of measurable precipitation annually.
- What hardiness zone is Clayton?
- Clayton sits in the USDA zone set by January lows near 31°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for Clayton?
- Clayton's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Clayton?
- See this week's day-by-day rain chances for Clayton in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Clayton?
- Current conditions for Clayton and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Clayton forecast updated?
- The Clayton forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Clayton?
- Today's sunrise and sunset times for Clayton are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Clayton?
- The next few days in Clayton's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Clayton, Missouri has a humid subtropical climate: January averages roughly 31°F, July about 81°F, 50°F between them.
Rain and snow bring Clayton roughly 39 inches a year across approximately 161 measurable-precipitation days.
At 38.6°N, Clayton's 50°F summer-to-winter swing sets when Clayton's gardens wake and when frost returns.
ZIP codes in Clayton
- 63105
- 63195
- 63199