Duncan, Iowa Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Duncan weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Heavy Rain35%0.88″79°66°—
- SundayJul 5Heavy Rain20%0.35″83°65°+4°
- MondayJul 6Light Drizzle——84°66°+1°
- TuesdayJul 7Overcast13%—84°65°0°
- WednesdayJul 8Thunderstorm52%0.09″82°67°-2°
- ThursdayJul 9Overcast52%—79°61°-3°
- FridayJul 10Overcast——78°61°-1°
AQI 37 (Good), driven by Ozone. AQI up 6 over the last 6 hours (gradual rise). Ozone at AQI 48 — peak already passed at 1 PM under overcast skies. 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 48 — peak already passed at 1 PM under overcast skies. Levels should ease through evening.
- Present
- AQI 48
- UV peak
- 2.6 at earlier today
- Sky at peak
- overcast
- Projected peak
- AQI 48
PM × Wind × Precip
PM scrubbed by 2 hours of recent rain — PM2.5 down to 6.9 µg/m³, PM10 to 8.9 µg/m³.
- PM2.5/PM10
- 0.78
- Wind
- light
- 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).
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:14 PM
- Moonset
- 10:17 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Duncan at a glance
- Today vs. normal: 3°F above the seasonal normal for this latitude
- Last frost: May 5 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Duncan
- Sat82°66°35%
- Sun83°65°20%
- Mon84°66°2%
- Tue84°65°13%
- Wed82°67°52%
- Thu79°61°52%
- Fri78°61°6%
- Sat77°56°11%
- Sun78°56°7%
- Mon80°58°9%
- Tue82°60°4%
- Wed83°61°13%
- Thu85°68°19%
- Fri86°63°29%
- Sat71°58°19%
- Sun78°59°26%
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 — Duncan
SPC includes Duncan in the general thunderstorm area today — no severe risk, but storms are possible.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3NONENo severe risk
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 Duncan
- 50423
- 50438