Stephan, South Dakota Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Stephan weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Overcast13%—86°62°—
- SundayJul 5Clear——91°66°+5°
- MondayJul 6Heavy Showers54%0.35″101°68°+10°
- TuesdayJul 7Light Showers63%0.25″100°68°-1°
- WednesdayJul 8Overcast63%—81°66°-19°
- ThursdayJul 9Showers13%0.27″82°64°+1°
- FridayJul 10Clear15%—79°62°-3°
AQI 53 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 18.7 µg/m³, PM10 at 26.5 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 47 now. With UV 7.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 44 around 1 PM.
- Present
- AQI 47
- UV peak
- 7.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 44
PM × Wind × Precip
PM2.5 at 18.7 µg/m³, PM10 at 26.5 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.71
- 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
- 11:40 PM
- Moonset
- 10:40 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Stephan at a glance
- Today vs. normal: 14°F above the seasonal normal for this latitude
- Last frost: May 11 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 57346
16-Day Forecast — Stephan
- Sat86°62°13%
- Sun91°66°6%
- Mon101°68°54%
- Tue100°68°63%
- Wed81°66°63%
- Thu82°64°13%
- Fri79°62°15%
- Sat82°58°15%
- Sun88°63°8%
- Mon90°66°6%
- Tue96°65°10%
- Wed103°69°14%
- Thu90°75°13%
- Fri85°68°20%
- Sat84°61°12%
- Sun88°59°18%
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 — Stephan
SPC includes Stephan in the general thunderstorm area today — no severe risk, but storms are possible.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWNONENo severe risk
- 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.
ZIP codes in Stephan
- 57346