Jefferson, South Dakota Weather
Prairie lightning bugs rise. Day 77 of spring. Read this microseason across nine climate regions →
Jefferson weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast30%—79°67°—
- FridayJun 5Overcast14%—86°66°+7°
- SaturdayJun 6Overcast11%—85°63°-1°
- SundayJun 7Overcast39%—84°70°-1°
- MondayJun 8Light Drizzle35%—83°67°-1°
- TuesdayJun 9Thunderstorm25%—91°65°+8°
- WednesdayJun 10Thunderstorm14%—98°75°+7°
Ozone at AQI 30. AQI down 38 over the last 6 hours — air quality is improving sharply. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 10 AM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 30. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 30
- UV peak
- 3.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 7
PM × Wind × Precip
PM2.5 at 4.6 µg/m³, PM10 at 4.9 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.94
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 5:04 AM
- Moonset
- 2:20 PM
- In sign
- ♑︎ Capricorn
Prairie lightning bugs rise
Jefferson at a glance
- Today vs. normal: 3°F below the seasonal normal for this latitude
- Last frost: May 2 (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 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 — Jefferson
SPC has placed Jefferson in the Slight Risk category for severe thunderstorms tomorrow.
- TODAYMRGLMarginal Risk
- TOMORROWSLGTSlight Risk
- 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.