| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 7.8° | 1.4° | 44.6mm | 15.4 | 30 |
| February | 9.4° | 1.4° | 38.7mm | 11.8 | 42 |
| March | 13° | 5.3° | 42.6mm | 12.1 | 53 |
| April | 17.4° | 7.7° | 35.6mm | 10.2 | 71 |
| May | 20.8° | 10.8° | 68.5mm | 12.4 | 75 |
| June | 24.6° | 14.5° | 52.9mm | 10.7 | 79 |
| July | 26.8° | 16.4° | 51.9mm | 9.8 | 80 |
| August | 26.1° | 15.8° | 59.5mm | 10.9 | 78 |
| September | 22.5° | 13.3° | 39.1mm | 9.9 | 80 |
| October | 17.5° | 9.8° | 54.6mm | 15.9 | 62 |
| November | 11.8° | — | 45.3mm | 15.4 | 44 |
| December | 8.8° | 2.6° | 60.8mm | 16 | 34 |
January in Issy-les-Moulineaux averages a daily high of 7.8°C with nights around 1.4°C. Expect roughly 15.4 wet days totalling 44.6mm. A hard month to visit for comfort alone.
February in Issy-les-Moulineaux averages a daily high of 9.4°C with nights around 1.4°C. Expect roughly 11.8 wet days totalling 38.7mm. Demanding conditions — pack for it and plan indoor options.
March in Issy-les-Moulineaux averages a daily high of 13°C with nights around 5.3°C. Expect roughly 12.1 wet days totalling 42.6mm. Demanding conditions — pack for it and plan indoor options.
April in Issy-les-Moulineaux averages a daily high of 17.4°C with nights around 7.7°C. Expect roughly 10.2 wet days totalling 35.6mm. Generally workable, with some weather to plan around.
May in Issy-les-Moulineaux averages a daily high of 20.8°C with nights around 10.8°C. Expect roughly 12.4 wet days totalling 68.5mm. Comfortable conditions for being outdoors all day.
June in Issy-les-Moulineaux averages a daily high of 24.6°C with nights around 14.5°C. Expect roughly 10.7 wet days totalling 52.9mm. Comfortable conditions for being outdoors all day.
July in Issy-les-Moulineaux averages a daily high of 26.8°C with nights around 16.4°C. Expect roughly 9.8 wet days totalling 51.9mm. Comfortable conditions for being outdoors all day.
August in Issy-les-Moulineaux averages a daily high of 26.1°C with nights around 15.8°C. Expect roughly 10.9 wet days totalling 59.5mm. Comfortable conditions for being outdoors all day.
September in Issy-les-Moulineaux averages a daily high of 22.5°C with nights around 13.3°C. Expect roughly 9.9 wet days totalling 39.1mm. Comfortable conditions for being outdoors all day.
October in Issy-les-Moulineaux averages a daily high of 17.5°C with nights around 9.8°C. Expect roughly 15.9 wet days totalling 54.6mm. Generally workable, with some weather to plan around.
November in Issy-les-Moulineaux averages a daily high of 11.8°C. Expect roughly 15.4 wet days totalling 45.3mm. Demanding conditions — pack for it and plan indoor options.
December in Issy-les-Moulineaux averages a daily high of 8.8°C with nights around 2.6°C. Expect roughly 16 wet days totalling 60.8mm. 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. Issy-les-Moulineaux peaks at 80.
Based on 30 years of records, May–September scores highest for comfort in Issy-les-Moulineaux, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 26.8°C.
May is the wettest, averaging 68.5mm of rain across roughly 12.4 wet days.
January is the coolest month, with average daily highs around 7.8°C.