| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -1.3° | -9.6° | 41.7mm | 10.2 | 10 |
| February | 1.2° | -8.2° | 41.8mm | 8.4 | 13 |
| March | 8.4° | -2.2° | 61.3mm | 10.5 | 36 |
| April | 15.6° | 3.4° | 93.7mm | 11.8 | 62 |
| May | 21.9° | 9.6° | 108.8mm | 13.2 | 74 |
| June | 27.3° | 15.2° | 122.3mm | 11 | 77 |
| July | 29° | 17.4° | 102.9mm | 9.2 | 74 |
| August | 28° | 16.5° | 108.6mm | 9.1 | 78 |
| September | 24.6° | 11.9° | 85.9mm | 7.8 | 84 |
| October | 17.2° | 5.4° | 70.9mm | 9.4 | 72 |
| November | 8.8° | -1° | 49.1mm | 8.2 | 43 |
| December | 1.7° | -6.6° | 50.4mm | 9.7 | 13 |
January in Rockford averages a daily high of -1.3°C with nights around -9.6°C. Expect roughly 10.2 wet days totalling 41.7mm. A hard month to visit for comfort alone.
February in Rockford averages a daily high of 1.2°C with nights around -8.2°C. Expect roughly 8.4 wet days totalling 41.8mm. A hard month to visit for comfort alone.
March in Rockford averages a daily high of 8.4°C with nights around -2.2°C. Expect roughly 10.5 wet days totalling 61.3mm. Demanding conditions — pack for it and plan indoor options.
April in Rockford averages a daily high of 15.6°C with nights around 3.4°C. Expect roughly 11.8 wet days totalling 93.7mm. Generally workable, with some weather to plan around.
May in Rockford averages a daily high of 21.9°C with nights around 9.6°C. Expect roughly 13.2 wet days totalling 108.8mm. Generally workable, with some weather to plan around.
June in Rockford averages a daily high of 27.3°C with nights around 15.2°C. Expect roughly 11 wet days totalling 122.3mm. Comfortable conditions for being outdoors all day.
July in Rockford averages a daily high of 29°C with nights around 17.4°C. Expect roughly 9.2 wet days totalling 102.9mm. Generally workable, with some weather to plan around.
August in Rockford averages a daily high of 28°C with nights around 16.5°C. Expect roughly 9.1 wet days totalling 108.6mm. Comfortable conditions for being outdoors all day.
September in Rockford averages a daily high of 24.6°C with nights around 11.9°C. Expect roughly 7.8 wet days totalling 85.9mm. Comfortable conditions for being outdoors all day.
October in Rockford averages a daily high of 17.2°C with nights around 5.4°C. Expect roughly 9.4 wet days totalling 70.9mm. Generally workable, with some weather to plan around.
November in Rockford averages a daily high of 8.8°C with nights around -1°C. Expect roughly 8.2 wet days totalling 49.1mm. Demanding conditions — pack for it and plan indoor options.
December in Rockford averages a daily high of 1.7°C with nights around -6.6°C. Expect roughly 9.7 wet days totalling 50.4mm. 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. Rockford peaks at 84.
Based on 30 years of records, August–September scores highest for comfort in Rockford, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 29°C.
June is the wettest, averaging 122.3mm of rain across roughly 11 wet days.
January is the coolest month, with average daily highs around -1.3°C.