Caledonia, Illinois Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Caledonia weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Heavy Rain59%0.93″83°68°—
- SundayJul 5Overcast17%—82°63°-1°
- MondayJul 6Overcast——79°62°-3°
- TuesdayJul 7Overcast——80°56°+1°
- WednesdayJul 8Overcast15%—80°61°0°
- ThursdayJul 9Light Showers50%0.13″75°65°-5°
- FridayJul 10Overcast36%—78°61°+3°
AQI 31 (Good), driven by Ozone. AQI flat over the last 6 hours (within ±3 points). Ozone at AQI 35. Overcast through the UV peak window (cloud cover ~64%) — afternoon ozone should stay flat.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 10 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 35. Overcast through the UV peak window (cloud cover ~64%) — afternoon ozone should stay flat.
- Present
- AQI 35
- UV peak
- 3.4 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 8
PM × Wind × Precip
PM2.5 at 4.8 µg/m³ (AQI 27) with a 0.73 fine-to-coarse ratio and 4 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.73
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
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
- 10:54 PM
- Moonset
- 9:59 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Caledonia at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: April 30 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 61011
16-Day Forecast — Caledonia
- Sat83°68°59%
- Sun82°63°17%
- Mon79°62°1%
- Tue80°56°1%
- Wed80°61°15%
- Thu75°65°50%
- Fri78°61°36%
- Sat81°60°11%
- Sun66°57°8%
- Mon73°54°8%
- Tue74°58°8%
- Wed78°61°25%
- Thu82°65°14%
- Fri83°67°26%
- Sat85°68°30%
- Sun84°70°29%
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 — Caledonia
SPC includes Caledonia 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.
Microseason · July 1–5
Cicadas claim the afternoon
Annual cicada buzz begins, peaking in the heat of the day.
Day 185 of 365 · Wedge 37 of 72
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
Caledonia peaks at about 74°F in July and bottoms near 22°F in January; June brings the heaviest rain (5.2 inches) and January the least (1.6 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 22° | 1.6″ | 4 |
| February | 26° | 1.6″ | 4 |
| March | 37° | 2.4″ | 5 |
| April | 49° | 3.8″ | 7 |
| May | 60° | 4.2″ | 8 |
| June | 70° | 5.2″ | 8 |
| July | 74° | 3.8″ | 6 |
| August | 72° | 4.2″ | 6 |
| September | 64° | 3.6″ | 5 |
| October | 52° | 2.6″ | 5 |
| November | 39° | 2.3″ | 5 |
| December | 27° | 1.9″ | 5 |
Frequently asked
- When does it freeze in Caledonia?
- Frost typically leaves Caledonia by mid-May and returns to Caledonia near mid-October.
- What is the rainy season in Caledonia?
- Caledonia sees its heaviest rain in June (around 5.2 inches), part of roughly 37 inches a year.
- What is the warmest month in Caledonia?
- Caledonia peaks in July, when the mean runs near 74°F.
- What is the coldest month in Caledonia?
- January is Caledonia's coldest month, averaging about 22°F.
- When can I start a vegetable garden in Caledonia?
- In Caledonia, sow peas and hardy greens around mid-May; Caledonia's tomatoes and peppers wait two weeks more.
- How many rainy days does Caledonia get?
- Expect roughly 69 wet days a year in Caledonia.
- What hardiness zone is Caledonia?
- With January around 22°F, Caledonia's zone reflects that minimum — the USDA ZIP map confirms Caledonia's band.
- What is the 10-day forecast for Caledonia?
- Caledonia's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Caledonia?
- See this week's day-by-day rain chances for Caledonia in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Caledonia?
- Current conditions for Caledonia and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Caledonia forecast updated?
- The Caledonia forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Caledonia?
- Today's sunrise and sunset times for Caledonia are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Caledonia?
- The next few days in Caledonia's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
The warm-summer humid continental climate of Caledonia, Illinois carries typical Januarys near 22°F and Julys around 74°F — 52°F of seasonal travel.
In a typical year Caledonia records about 37 inches of precipitation on around 69 days.
Caledonia sits at 42.4°N; that 52°F seasonal swing frames planting windows and frost dates across Caledonia.
ZIP codes in Caledonia
- 61011