Williamstown, Missouri Weather
Fireflies pulse through the magnolias. Day 78 of spring. Read this microseason across nine climate regions →
Williamstown weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 5Thunderstorm84%0.13″83°69°—
- SaturdayJun 6Thunderstorm17%—89°71°+6°
- SundayJun 7Showers68%0.04″82°68°-7°
- MondayJun 8Drizzle71%—83°67°+1°
- TuesdayJun 9Thunderstorm49%—90°72°+7°
- WednesdayJun 10Thunderstorm15%—91°74°+1°
- ThursdayJun 11Clear——91°73°0°
AQI 50 (Good), driven by PM2.5. AQI down 18 over the last 6 hours — air quality is improving sharply. PM2.5 at 8.3 µg/m³, PM10 at 9.0 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 39. Overcast through the UV peak window (cloud cover ~88%) — afternoon ozone should stay flat.
- Present
- AQI 39
- UV peak
- 3.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 9
PM × Wind × Precip
PM2.5 at 8.3 µg/m³, PM10 at 9.0 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.92
- 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).
The higher the clouds, the finer the weather.
- Moonrise
- 5:08 AM
- Moonset
- 3:14 PM
- In sign
- ♒︎ Aquarius
Fireflies pulse through the magnolias
Williamstown at a glance
- Today vs. normal: 3°F below the seasonal normal for this latitude
- Last frost: April 17 (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 — Williamstown
SPC has placed Williamstown in the Marginal Risk category for severe thunderstorms tomorrow.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWMRGLMarginal Risk
- DAY 3TSTMGeneral Thunderstorms
Isolated severe storms possible. Limited threat for hail or damaging wind.
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.