| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 7.2° | 1.2° | 53.2mm | 13.9 | 30 |
| February | 8.3° | 1.9° | 41.8mm | 12.6 | 37 |
| March | 10.6° | 2.8° | 40.4mm | 11.8 | 46 |
| April | 13.3° | 4.3° | 44.1mm | 10.9 | 57 |
| May | 16.6° | 7.4° | 54.4mm | 12 | 65 |
| June | 19.4° | 10.3° | 51mm | 10.6 | 77 |
| July | 21.7° | 12.4° | 53.2mm | 11.2 | 78 |
| August | 21.5° | 12.4° | 54.4mm | 11.8 | 76 |
| September | 18.6° | 10.2° | 50.1mm | 10.5 | 75 |
| October | 14.5° | 7.6° | 69.3mm | 14.1 | 54 |
| November | 10° | 4° | 63.1mm | 14.5 | 39 |
| December | 7.3° | 1.6° | 53.7mm | 14.2 | 30 |
January in Grimsby averages a daily high of 7.2°C with nights around 1.2°C. Expect roughly 13.9 wet days totalling 53.2mm. A hard month to visit for comfort alone.
February in Grimsby averages a daily high of 8.3°C with nights around 1.9°C. Expect roughly 12.6 wet days totalling 41.8mm. Demanding conditions — pack for it and plan indoor options.
March in Grimsby averages a daily high of 10.6°C with nights around 2.8°C. Expect roughly 11.8 wet days totalling 40.4mm. Demanding conditions — pack for it and plan indoor options.
April in Grimsby averages a daily high of 13.3°C with nights around 4.3°C. Expect roughly 10.9 wet days totalling 44.1mm. Generally workable, with some weather to plan around.
May in Grimsby averages a daily high of 16.6°C with nights around 7.4°C. Expect roughly 12 wet days totalling 54.4mm. Generally workable, with some weather to plan around.
June in Grimsby averages a daily high of 19.4°C with nights around 10.3°C. Expect roughly 10.6 wet days totalling 51mm. Comfortable conditions for being outdoors all day.
July in Grimsby averages a daily high of 21.7°C with nights around 12.4°C. Expect roughly 11.2 wet days totalling 53.2mm. Comfortable conditions for being outdoors all day.
August in Grimsby averages a daily high of 21.5°C with nights around 12.4°C. Expect roughly 11.8 wet days totalling 54.4mm. Comfortable conditions for being outdoors all day.
September in Grimsby averages a daily high of 18.6°C with nights around 10.2°C. Expect roughly 10.5 wet days totalling 50.1mm. Comfortable conditions for being outdoors all day.
October in Grimsby averages a daily high of 14.5°C with nights around 7.6°C. Expect roughly 14.1 wet days totalling 69.3mm. Demanding conditions — pack for it and plan indoor options.
November in Grimsby averages a daily high of 10°C with nights around 4°C. Expect roughly 14.5 wet days totalling 63.1mm. Demanding conditions — pack for it and plan indoor options.
December in Grimsby averages a daily high of 7.3°C with nights around 1.6°C. Expect roughly 14.2 wet days totalling 53.7mm. 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. Grimsby peaks at 78.
Based on 30 years of records, June–September scores highest for comfort in Grimsby, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 21.7°C.
October is the wettest, averaging 69.3mm of rain across roughly 14.1 wet days.
January is the coolest month, with average daily highs around 7.2°C.