Mason City, Iowa Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Mason City weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Overcast25%—82°67°—
- SundayJul 5Overcast20%—80°66°-2°
- MondayJul 6Light Drizzle——82°64°+2°
- TuesdayJul 7Overcast——84°64°+2°
- WednesdayJul 8Thunderstorm49%0.02″82°67°-2°
- ThursdayJul 9Overcast49%—79°60°-3°
- FridayJul 10Light Drizzle——78°63°-1°
AQI 36 (Good), driven by Ozone. AQI flat over the last 6 hours (within ±3 points). Ozone at AQI 48 — peak already passed at 1 PM under clear 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 clear skies. Levels should ease through evening.
- Present
- AQI 48
- UV peak
- 4.1 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 48
PM × Wind × Precip
PM2.5 at 7.1 µg/m³, PM10 at 9.0 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.79
- 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
- 11:12 PM
- Moonset
- 10:15 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Mason City at a glance
- Today vs. normal: 11°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.
ZIP code: 50401
16-Day Forecast — Mason City
- Sat82°67°25%
- Sun80°66°20%
- Mon82°64°1%
- Tue84°64°4%
- Wed82°67°49%
- Thu79°60°49%
- Fri78°63°8%
- Sat76°57°10%
- Sun78°56°14%
- Mon80°57°11%
- Tue81°60°4%
- Wed80°61°17%
- Thu84°64°26%
- Fri83°62°29%
- Sat71°59°23%
- Sun77°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 — Mason City
SPC includes Mason City 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 Mason City
- 50401
- 50402