Weather in Champaign, Illinois
Roses open on the Piedmont edge. Day 59 of spring. Read this microseason across nine climate regions →
- TodayMay 16Light Drizzle50%74°63°
- SundayMay 17Overcast15%84°62°
- MondayMay 18Heavy Rain66%81°68°
- TuesdayMay 19Light Showers77%79°60°
- WednesdayMay 20Overcast75%67°49°
- ThursdayMay 21Overcast—65°45°
- FridayMay 22Heavy Drizzle14%57°53°
- PM 2.5
- 6.2 μg/m³
- PM 10
- 7.0 μg/m³
- NO₂
- 5.5 μg/m³
- Ozone
- 77.0 μg/m³
- UV Index
- 0.0 Low
When the dew is on the grass, rain will never come to pass.
- Moonrise
- 10:42 AM
- Moonset
- 1:32 AM
- In sign
- ♊︎ Gemini
Roses open on the Piedmont edge
Champaign at a glance
- Today vs. normal: 8°F below the seasonal normal for this latitude
- Last frost: April 17 (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
Warm-season window is open
As of May 17, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
July stands as Champaign's warmest month with mean temperatures around 75°F, while January claims the coldest spot at roughly 26°F. May brings peak rainfall at 4.8 inches, contrasting with February's drier 2.2 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 26° | 2.3″ | 5 |
| February | 30° | 2.2″ | 5 |
| March | 41° | 2.8″ | 6 |
| April | 52° | 3.9″ | 8 |
| May | 63° | 4.8″ | 9 |
| June | 72° | 4.6″ | 7 |
| July | 75° | 4.5″ | 7 |
| August | 74° | 3.5″ | 6 |
| September | 67° | 3.4″ | 5 |
| October | 55° | 3.4″ | 6 |
| November | 41° | 3.2″ | 6 |
| December | 31° | 2.4″ | 5 |
Regional context
Located within a humid subtropical climate region, Champaign shares temperature ranges, seasonal rhythms, and growing conditions with other nearby cities in this climate zone.
Similar climates: Peoria, IL, Springfield, IL, Bloomington, IL, Alton, IL, Decatur, IL.
Naturalist notes
Red-winged blackbirds return to cattail marshes around Champaign in mid-March, their territorial calls marking spring's arrival.
Wild bergamot begins blooming in late May, attracting native bees to prairie remnants throughout the area.
Frequently asked
- When does it freeze in Champaign?
- Spring's last frost usually occurs around mid-April in Champaign, while the first fall frost typically arrives around mid-November.
- What is the rainy season in Champaign?
- May records the highest rainfall with about 4.8 inches on average, contributing to the city's annual total of roughly 41 inches.
- What is the warmest month in Champaign?
- July typically registers as the warmest month, with average temperatures around 75°F.
- What is the coldest month in Champaign?
- January typically records as the coldest month, with average temperatures around 26°F.
- When can I start a vegetable garden in Champaign?
- Cool-season crops like peas and lettuce can be planted around the last spring frost in mid-April, while warm-season crops such as tomatoes and peppers should wait 1–2 weeks after.
- How many rainy days does Champaign get?
- Champaign experiences about 74 rainy days per year on average.
- What hardiness zone is Champaign?
- Champaign's USDA hardiness zone depends on its lowest average winter temperatures; the USDA's online lookup tool can provide the current zone designation using the city ZIP code.
Climate
Champaign, Illinois experiences a humid subtropical climate. Winter temperatures in January hover near 26°F, while July brings averages around 75°F — creating a 50°F seasonal swing.
Annual precipitation totals about 41 inches, distributed across roughly 74 rainy days throughout the year.
Weather patterns here respond to the city's latitude of 40.1°N, its distance from major water bodies, and local elevation. These factors determine growing seasons, frost timing, and daily weather variations.