| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -3.3° | -12.2° | 33.4mm | 6.6 | 17 |
| February | -1.3° | -12° | 33.9mm | 6.3 | 17 |
| March | 5° | -5.6° | 54.8mm | 7.2 | 26 |
| April | 12° | 0.6° | 82.9mm | 9.5 | 53 |
| May | 19.5° | 7.1° | 100.5mm | 10.7 | 77 |
| June | 24.3° | 12.8° | 106.7mm | 11.3 | 77 |
| July | 26.9° | 15.2° | 95mm | 9.8 | 80 |
| August | 25.8° | 14.4° | 98.8mm | 8.5 | 83 |
| September | 22.3° | 10.3° | 79.7mm | 8.3 | 83 |
| October | 15.3° | 4.3° | 78.2mm | 8.6 | 68 |
| November | 7.4° | -2.3° | 48.7mm | 6.4 | 40 |
| December | 0.1° | -8° | 52.1mm | 8.1 | 14 |
January in Green Bay averages a daily high of -3.3°C with nights around -12.2°C. Expect roughly 6.6 wet days totalling 33.4mm. A hard month to visit for comfort alone.
February in Green Bay averages a daily high of -1.3°C with nights around -12°C. Expect roughly 6.3 wet days totalling 33.9mm. A hard month to visit for comfort alone.
March in Green Bay averages a daily high of 5°C with nights around -5.6°C. Expect roughly 7.2 wet days totalling 54.8mm. A hard month to visit for comfort alone.
April in Green Bay averages a daily high of 12°C with nights around 0.6°C. Expect roughly 9.5 wet days totalling 82.9mm. Demanding conditions — pack for it and plan indoor options.
May in Green Bay averages a daily high of 19.5°C with nights around 7.1°C. Expect roughly 10.7 wet days totalling 100.5mm. Comfortable conditions for being outdoors all day.
June in Green Bay averages a daily high of 24.3°C with nights around 12.8°C. Expect roughly 11.3 wet days totalling 106.7mm. Comfortable conditions for being outdoors all day.
July in Green Bay averages a daily high of 26.9°C with nights around 15.2°C. Expect roughly 9.8 wet days totalling 95mm. Comfortable conditions for being outdoors all day.
August in Green Bay averages a daily high of 25.8°C with nights around 14.4°C. Expect roughly 8.5 wet days totalling 98.8mm. Comfortable conditions for being outdoors all day.
September in Green Bay averages a daily high of 22.3°C with nights around 10.3°C. Expect roughly 8.3 wet days totalling 79.7mm. Comfortable conditions for being outdoors all day.
October in Green Bay averages a daily high of 15.3°C with nights around 4.3°C. Expect roughly 8.6 wet days totalling 78.2mm. Generally workable, with some weather to plan around.
November in Green Bay averages a daily high of 7.4°C with nights around -2.3°C. Expect roughly 6.4 wet days totalling 48.7mm. Demanding conditions — pack for it and plan indoor options.
December in Green Bay averages a daily high of 0.1°C with nights around -8°C. Expect roughly 8.1 wet days totalling 52.1mm. 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. Green Bay peaks at 83.
Based on 30 years of records, May–September scores highest for comfort in Green Bay, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 26.9°C.
June is the wettest, averaging 106.7mm of rain across roughly 11.3 wet days.
January is the coolest month, with average daily highs around -3.3°C.