Osceola, Wisconsin Weather
Prairie lightning bugs rise. Day 78 of spring. Read this microseason across nine climate regions →
Osceola weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Heavy Rain49%0.54″82°68°—
- FridayJun 5Heavy Rain40%1.0″78°65°-4°
- SaturdayJun 6Foggy——82°59°+4°
- SundayJun 7Light Drizzle16%—80°59°-2°
- MondayJun 8Drizzle75%0.01″75°64°-5°
- TuesdayJun 9Overcast45%—82°68°+7°
- WednesdayJun 10Thunderstorm16%—93°72°+11°
AQI 55 (Moderate), driven by PM2.5. AQI up 7 over the last 6 hours (gradual rise). PM2.5 at 9.4 µg/m³, PM10 at 10.4 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 40. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 40
- UV peak
- 0.0 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 5
PM × Wind × Precip
PM2.5 at 9.4 µg/m³, PM10 at 10.4 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.90
- Wind
- light
- Recent rain
- 1h 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).
The higher the clouds, the finer the weather.
- Moonrise
- 5:27 AM
- Moonset
- 3:05 PM
- In sign
- ♒︎ Aquarius
Prairie lightning bugs rise
Osceola at a glance
- Today vs. normal: 72°F — typical for the season
- Last frost: May 18 (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 5, 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 — Osceola
SPC has placed Osceola in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWMRGLMarginal Risk
- DAY 3NONENo severe risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
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.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | — | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Osceola's warmest month is July (~71°F mean) and its coldest is January (~13°F). Rainfall peaks in July (4.2 inches) and bottoms out in January (0.6 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 13° | 0.6″ | 2 |
| February | 17° | 0.8″ | 3 |
| March | 30° | 1.3″ | 4 |
| April | 44° | 2.7″ | 6 |
| May | 57° | 4.1″ | 7 |
| June | 67° | 4.1″ | 7 |
| July | 71° | 4.2″ | 7 |
| August | 69° | 3.7″ | 6 |
| September | 61° | 3.6″ | 6 |
| October | 48° | 2.9″ | 6 |
| November | 33° | 1.4″ | 3 |
| December | 20° | 1.1″ | 3 |
Regional context
Osceola's climate, per the NOAA NCEI 1991-2020 normals from the nearest reporting station, runs cold-winter and warm-summer. January means hover near 13°F while July climbs to 71°F — a 58°F seasonal swing typical of northern-tier latitudes. Annual precipitation totals about 30.5 inches spread across roughly 59 days with measurable rain or snow.
Precipitation runs summer-dominant here: July averages 4.2 inches across 6.5 days with measurable rain, driven mostly by warm-season storms and thunderstorm activity, while January drops to just 0.6 inches across 1.8 rainy days under drier cool-season air. The warm-season-wet rhythm lines Osceola up with places like Dresser, WI, St. Croix Falls, WI and Centuria, WI, where the May-September stretch delivers the bulk of the year's precipitation.
The frost-sensitive growing window opens around late-May, when overnight lows reliably clear freezing for cool-season crops like kale, peas, spinach, and parsnips. Heat-loving transplants like tomatoes, peppers, and squash generally hold off for another 10-14 days to clear the last spring frost risk window. The window closes around early-October, when overnight lows resume dipping below freezing and frost-tender plants need protection or harvest. The dates above are 1991-2020 normals; in a given year either bookend can move 1-2 weeks either direction. Within Osceola, low-lying parcels along drainage features typically lose 4-7°F of overnight low temperature versus the bench positions on calm clear nights, which shifts the working last-frost date by a week or more.
Similar climates: Dresser, WI, St. Croix Falls, WI, Centuria, WI, Star Prairie, WI, Somerset, WI.
Frequently asked
- When does it freeze in Osceola?
- Osceola's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Osceola?
- July is the wettest month with about 4.2 inches of rain on average; the city receives roughly 30 inches annually.
- What is the warmest month in Osceola?
- July is typically warmest, averaging about 71°F.
- What is the coldest month in Osceola?
- January is typically coldest, averaging about 13°F.
- When can I start a vegetable garden in Osceola?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-May); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Osceola get?
- Osceola averages about 59 rainy days per year.
- What hardiness zone is Osceola?
- Osceola's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Osceola, Wisconsin sits in a warm-summer humid continental climate zone. January means hover near 13°F while July averages 71°F — a 58°F seasonal swing.
Across the year, Osceola receives about 30 inches of precipitation spread over roughly 59 rainy days.
The rhythm of the year is set by latitude (45.3°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.