| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 6.6° | 1.6° | 59.9mm | 15.2 | 27 |
| February | 8.2° | 2.3° | 52.6mm | 13.4 | 35 |
| March | 11.4° | 3.8° | 53.3mm | 12.5 | 47 |
| April | 15.1° | 5.9° | 42.2mm | 11 | 62 |
| May | 18.6° | 9.4° | 62.8mm | 12.8 | 70 |
| June | 21.8° | 12.4° | 61.8mm | 11.4 | 77 |
| July | 23.8° | 14.2° | 64.1mm | 11.6 | 77 |
| August | 24° | 14.2° | 72.9mm | 12.2 | 76 |
| September | 20.6° | 11.6° | 54.8mm | 11.5 | 77 |
| October | 16° | 8.8° | 67mm | 14.5 | 58 |
| November | 10.5° | 5° | 77mm | 16.8 | 40 |
| December | 7.3° | 2.4° | 69.2mm | 15.2 | 29 |
January in Lille averages a daily high of 6.6°C with nights around 1.6°C. Expect roughly 15.2 wet days totalling 59.9mm. A hard month to visit for comfort alone.
February in Lille averages a daily high of 8.2°C with nights around 2.3°C. Expect roughly 13.4 wet days totalling 52.6mm. Demanding conditions — pack for it and plan indoor options.
March in Lille averages a daily high of 11.4°C with nights around 3.8°C. Expect roughly 12.5 wet days totalling 53.3mm. Demanding conditions — pack for it and plan indoor options.
April in Lille averages a daily high of 15.1°C with nights around 5.9°C. Expect roughly 11 wet days totalling 42.2mm. Generally workable, with some weather to plan around.
May in Lille averages a daily high of 18.6°C with nights around 9.4°C. Expect roughly 12.8 wet days totalling 62.8mm. Generally workable, with some weather to plan around.
June in Lille averages a daily high of 21.8°C with nights around 12.4°C. Expect roughly 11.4 wet days totalling 61.8mm. Comfortable conditions for being outdoors all day.
July in Lille averages a daily high of 23.8°C with nights around 14.2°C. Expect roughly 11.6 wet days totalling 64.1mm. Comfortable conditions for being outdoors all day.
August in Lille averages a daily high of 24°C with nights around 14.2°C. Expect roughly 12.2 wet days totalling 72.9mm. Comfortable conditions for being outdoors all day.
September in Lille averages a daily high of 20.6°C with nights around 11.6°C. Expect roughly 11.5 wet days totalling 54.8mm. Comfortable conditions for being outdoors all day.
October in Lille averages a daily high of 16°C with nights around 8.8°C. Expect roughly 14.5 wet days totalling 67mm. Generally workable, with some weather to plan around.
November in Lille averages a daily high of 10.5°C with nights around 5°C. Expect roughly 16.8 wet days totalling 77mm. Demanding conditions — pack for it and plan indoor options.
December in Lille averages a daily high of 7.3°C with nights around 2.4°C. Expect roughly 15.2 wet days totalling 69.2mm. 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. Lille peaks at 77.
Based on 30 years of records, May–September scores highest for comfort in Lille, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 24°C.
November is the wettest, averaging 77mm of rain across roughly 16.8 wet days.
January is the coolest month, with average daily highs around 6.6°C.