Erwin, South Dakota Weather
Prairie lightning bugs rise. Day 77 of spring. Read this microseason across nine climate regions →
Erwin weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Light Drizzle73%0.02″84°63°—
- FridayJun 5Rain23%0.20″80°61°-4°
- SaturdayJun 6Clear——83°59°+3°
- SundayJun 7Overcast21%—86°63°+3°
- MondayJun 8Overcast27%—82°64°-4°
- TuesdayJun 9Partly Cloudy26%—90°61°+8°
- WednesdayJun 10Thunderstorm26%—97°73°+7°
Ozone at AQI 37 now. AQI down 6 over the last 6 hours (steady decline since this morning). With UV 3.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 12 by mid-afternoon.
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 37 now. With UV 3.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 12 by mid-afternoon.
- Present
- AQI 37
- UV peak
- 3.3 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 12
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
- 5:15 AM
- Moonset
- 2:17 PM
- In sign
- ♑︎ Capricorn
Prairie lightning bugs rise
Erwin at a glance
- Today vs. normal: 6°F below the seasonal normal for this latitude
- Last frost: May 13 (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 — Erwin
SPC has placed Erwin in the Slight Risk category for severe thunderstorms today.
- TODAYSLGTSlight Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3NONENo severe risk
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.