| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -5° | -13.9° | 21mm | 6.5 | 17 |
| February | -2.6° | -12.4° | 24.1mm | 5.8 | 18 |
| March | 2.6° | -5.9° | 40.3mm | 6.9 | 19 |
| April | 7.6° | -0.2° | 63.9mm | 9.4 | 38 |
| May | 14° | 5° | 79.4mm | 11.2 | 58 |
| June | 20.1° | 10° | 109.5mm | 11.2 | 78 |
| July | 25° | 14.7° | 87.4mm | 9.5 | 81 |
| August | 23.9° | 14.7° | 95.2mm | 9.3 | 81 |
| September | 19.7° | 10.8° | 79.4mm | 8.9 | 81 |
| October | 12.1° | 4.3° | 79.2mm | 9.7 | 55 |
| November | 4.7° | -2.8° | 47.8mm | 7.7 | 28 |
| December | -2.5° | -10.1° | 36.3mm | 6.8 | 16 |
January in Duluth averages a daily high of -5°C with nights around -13.9°C. Expect roughly 6.5 wet days totalling 21mm. A hard month to visit for comfort alone.
February in Duluth averages a daily high of -2.6°C with nights around -12.4°C. Expect roughly 5.8 wet days totalling 24.1mm. A hard month to visit for comfort alone.
March in Duluth averages a daily high of 2.6°C with nights around -5.9°C. Expect roughly 6.9 wet days totalling 40.3mm. A hard month to visit for comfort alone.
April in Duluth averages a daily high of 7.6°C with nights around -0.2°C. Expect roughly 9.4 wet days totalling 63.9mm. Demanding conditions — pack for it and plan indoor options.
May in Duluth averages a daily high of 14°C with nights around 5°C. Expect roughly 11.2 wet days totalling 79.4mm. Generally workable, with some weather to plan around.
June in Duluth averages a daily high of 20.1°C with nights around 10°C. Expect roughly 11.2 wet days totalling 109.5mm. Comfortable conditions for being outdoors all day.
July in Duluth averages a daily high of 25°C with nights around 14.7°C. Expect roughly 9.5 wet days totalling 87.4mm. Comfortable conditions for being outdoors all day.
August in Duluth averages a daily high of 23.9°C with nights around 14.7°C. Expect roughly 9.3 wet days totalling 95.2mm. Comfortable conditions for being outdoors all day.
September in Duluth averages a daily high of 19.7°C with nights around 10.8°C. Expect roughly 8.9 wet days totalling 79.4mm. Comfortable conditions for being outdoors all day.
October in Duluth averages a daily high of 12.1°C with nights around 4.3°C. Expect roughly 9.7 wet days totalling 79.2mm. Generally workable, with some weather to plan around.
November in Duluth averages a daily high of 4.7°C with nights around -2.8°C. Expect roughly 7.7 wet days totalling 47.8mm. A hard month to visit for comfort alone.
December in Duluth averages a daily high of -2.5°C with nights around -10.1°C. Expect roughly 6.8 wet days totalling 36.3mm. 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. Duluth peaks at 81.
Based on 30 years of records, June–September scores highest for comfort in Duluth, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 25°C.
June is the wettest, averaging 109.5mm of rain across roughly 11.2 wet days.
January is the coolest month, with average daily highs around -5°C.