Grimes, Iowa Weather
Prairie lightning bugs rise. Day 77 of spring. Read this microseason across nine climate regions →
Grimes weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Heavy Rain70%0.73″84°65°—
- FridayJun 5Thunderstorm68%0.09″80°68°-4°
- SaturdayJun 6Light Drizzle36%—87°67°+7°
- SundayJun 7Showers65%0.05″79°68°-8°
- MondayJun 8Thunderstorm54%0.01″86°67°+7°
- TuesdayJun 9Thunderstorm35%0.31″87°67°+1°
- WednesdayJun 10Thunderstorm16%—92°74°+5°
Ozone at AQI 51 — peak already passed at 1 PM under clear skies. AQI up 11 over the last 6 hours (gradual rise). Levels should ease through evening.
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 51 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
- Present
- AQI 51
- UV peak
- 3.4 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 51
PM × Wind × Precip
PM scrubbed by 2 hours of recent rain — PM2.5 down to 7.2 µg/m³, PM10 to 8.0 µg/m³.
- PM2.5/PM10
- 0.90
- Wind
- breezy
- Recent rain
- 2h in last 6h
- Pattern
- washed out
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
- 4:50 AM
- Moonset
- 2:12 PM
- In sign
- ♒︎ Aquarius
Prairie lightning bugs rise
Grimes at a glance
- Today vs. normal: 10°F above the seasonal normal for this latitude
- Last frost: April 26 (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 — Grimes
SPC has placed Grimes 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.