| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 1.1° | -7.5° | 59.7mm | 10 | 11 |
| February | 3.8° | -5.8° | 56.8mm | 9.2 | 18 |
| March | 10.7° | -0.4° | 73.8mm | 10.7 | 45 |
| April | 17.5° | 5.1° | 95.1mm | 11.7 | 69 |
| May | 23.4° | 11.4° | 119.4mm | 13.8 | 72 |
| June | 28.3° | 16.6° | 117.8mm | 11.1 | 73 |
| July | 29.6° | 18.4° | 107mm | 10 | 70 |
| August | 29° | 17.6° | 90.6mm | 9 | 74 |
| September | 26.3° | 13.3° | 83.4mm | 7.6 | 85 |
| October | 19° | 6.6° | 86mm | 10.2 | 76 |
| November | 10.7° | 0.3° | 73.3mm | 9.2 | 49 |
| December | 3.9° | -4.4° | 65.2mm | 10.6 | 18 |
January in Champaign averages a daily high of 1.1°C with nights around -7.5°C. Expect roughly 10 wet days totalling 59.7mm. A hard month to visit for comfort alone.
February in Champaign averages a daily high of 3.8°C with nights around -5.8°C. Expect roughly 9.2 wet days totalling 56.8mm. A hard month to visit for comfort alone.
March in Champaign averages a daily high of 10.7°C with nights around -0.4°C. Expect roughly 10.7 wet days totalling 73.8mm. Demanding conditions — pack for it and plan indoor options.
April in Champaign averages a daily high of 17.5°C with nights around 5.1°C. Expect roughly 11.7 wet days totalling 95.1mm. Generally workable, with some weather to plan around.
May in Champaign averages a daily high of 23.4°C with nights around 11.4°C. Expect roughly 13.8 wet days totalling 119.4mm. Generally workable, with some weather to plan around.
June in Champaign averages a daily high of 28.3°C with nights around 16.6°C. Expect roughly 11.1 wet days totalling 117.8mm. Generally workable, with some weather to plan around.
July in Champaign averages a daily high of 29.6°C with nights around 18.4°C. Expect roughly 10 wet days totalling 107mm. Generally workable, with some weather to plan around.
August in Champaign averages a daily high of 29°C with nights around 17.6°C. Expect roughly 9 wet days totalling 90.6mm. Generally workable, with some weather to plan around.
September in Champaign averages a daily high of 26.3°C with nights around 13.3°C. Expect roughly 7.6 wet days totalling 83.4mm. Comfortable conditions for being outdoors all day.
October in Champaign averages a daily high of 19°C with nights around 6.6°C. Expect roughly 10.2 wet days totalling 86mm. Comfortable conditions for being outdoors all day.
November in Champaign averages a daily high of 10.7°C with nights around 0.3°C. Expect roughly 9.2 wet days totalling 73.3mm. Demanding conditions — pack for it and plan indoor options.
December in Champaign averages a daily high of 3.9°C with nights around -4.4°C. Expect roughly 10.6 wet days totalling 65.2mm. A hard month to visit for comfort alone.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. Champaign peaks at 85.
Based on 30 years of records, September scores highest for comfort in Champaign, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 29.6°C.
May is the wettest, averaging 119.4mm of rain across roughly 13.8 wet days.
January is the coolest month, with average daily highs around 1.1°C.