Weather in Caledonia, Illinois
Roses open along the stoops. Day 59 of spring. Read this microseason across nine climate regions →
- TodayMay 16Heavy Drizzle51%82°59°
- SundayMay 17Light Showers49%85°65°
- MondayMay 18Light Showers71%78°65°
- TuesdayMay 19Showers62%72°51°
- WednesdayMay 20Overcast—59°43°
- ThursdayMay 21Overcast—62°39°
- FridayMay 22Overcast12%66°47°
- PM 2.5
- 4.2 μg/m³
- PM 10
- 5.3 μg/m³
- NO₂
- 12.5 μg/m³
- Ozone
- 73.0 μg/m³
- UV Index
- 0.0 Low
When the dew is on the grass, rain will never come to pass.
- Moonrise
- 10:36 AM
- Moonset
- 1:43 AM
- In sign
- ♊︎ Gemini
Roses open along the stoops
Caledonia at a glance
- Today vs. normal: 70°F — typical for the season
- Last frost: April 30 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Cool-season window is open
As of May 17, the cool-season window is open or about to open. Direct-sow peas, lettuce, spinach, radishes, and brassicas now. Hold off on warm-season crops until 1–2 weeks after the last spring frost (around May).
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's warmest month is July (~74°F mean) and its coldest is January (~22°F). Rainfall peaks in June (5.2 inches) and bottoms out in January (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?
- Caledonia's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Caledonia?
- June is the wettest month with about 5.2 inches of rain on average; the city receives roughly 37 inches annually.
- What is the warmest month in Caledonia?
- July is typically warmest, averaging about 74°F.
- What is the coldest month in Caledonia?
- January is typically coldest, averaging about 22°F.
- When can I start a vegetable garden in Caledonia?
- 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 Caledonia get?
- Caledonia averages about 69 rainy days per year.
- What hardiness zone is Caledonia?
- Caledonia'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
Caledonia, Illinois sits in a warm-summer humid continental climate zone. January means hover near 22°F while July averages 74°F — a 52°F seasonal swing.
Across the year, Caledonia receives about 37 inches of precipitation spread over roughly 69 rainy days.
The rhythm of the year is set by latitude (42.4°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.