| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 0.8° | -6.9° | 57.6mm | 12.7 | 6 |
| February | 2.3° | -6.8° | 52.8mm | 10.2 | 11 |
| March | 8.4° | -2.1° | 65.9mm | 9.6 | 38 |
| April | 15° | 3.1° | 78.5mm | 11.9 | 60 |
| May | 21.8° | 9.7° | 92.1mm | 12 | 76 |
| June | 26.9° | 15.6° | 95.4mm | 10.5 | 79 |
| July | 29.2° | 18° | 89.5mm | 10.8 | 70 |
| August | 28.2° | 17.3° | 100.2mm | 9.7 | 76 |
| September | 24.8° | 13.5° | 80.3mm | 8.8 | 82 |
| October | 17.7° | 7.1° | 63.6mm | 12.1 | 68 |
| November | 10.2° | 1° | 61.8mm | 9.6 | 48 |
| December | 4.1° | -2.8° | 62.9mm | 11.6 | 19 |
January in Dearborn averages a daily high of 0.8°C with nights around -6.9°C. Expect roughly 12.7 wet days totalling 57.6mm. A hard month to visit for comfort alone.
February in Dearborn averages a daily high of 2.3°C with nights around -6.8°C. Expect roughly 10.2 wet days totalling 52.8mm. A hard month to visit for comfort alone.
March in Dearborn averages a daily high of 8.4°C with nights around -2.1°C. Expect roughly 9.6 wet days totalling 65.9mm. Demanding conditions — pack for it and plan indoor options.
April in Dearborn averages a daily high of 15°C with nights around 3.1°C. Expect roughly 11.9 wet days totalling 78.5mm. Generally workable, with some weather to plan around.
May in Dearborn averages a daily high of 21.8°C with nights around 9.7°C. Expect roughly 12 wet days totalling 92.1mm. Comfortable conditions for being outdoors all day.
June in Dearborn averages a daily high of 26.9°C with nights around 15.6°C. Expect roughly 10.5 wet days totalling 95.4mm. Comfortable conditions for being outdoors all day.
July in Dearborn averages a daily high of 29.2°C with nights around 18°C. Expect roughly 10.8 wet days totalling 89.5mm. Generally workable, with some weather to plan around.
August in Dearborn averages a daily high of 28.2°C with nights around 17.3°C. Expect roughly 9.7 wet days totalling 100.2mm. Comfortable conditions for being outdoors all day.
September in Dearborn averages a daily high of 24.8°C with nights around 13.5°C. Expect roughly 8.8 wet days totalling 80.3mm. Comfortable conditions for being outdoors all day.
October in Dearborn averages a daily high of 17.7°C with nights around 7.1°C. Expect roughly 12.1 wet days totalling 63.6mm. Generally workable, with some weather to plan around.
November in Dearborn averages a daily high of 10.2°C with nights around 1°C. Expect roughly 9.6 wet days totalling 61.8mm. Demanding conditions — pack for it and plan indoor options.
December in Dearborn averages a daily high of 4.1°C with nights around -2.8°C. Expect roughly 11.6 wet days totalling 62.9mm. 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. Dearborn peaks at 82.
Based on 30 years of records, May–June scores highest for comfort in Dearborn, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 29.2°C.
August is the wettest, averaging 100.2mm of rain across roughly 9.7 wet days.
January is the coolest month, with average daily highs around 0.8°C.