| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 4.6° | 0° | 43.5mm | 12.6 | 23 |
| February | 6.8° | 0.6° | 40.1mm | 11.1 | 33 |
| March | 11.3° | 3.1° | 42.3mm | 11 | 50 |
| April | 16.3° | 6.3° | 37.8mm | 9.9 | 68 |
| May | 20.3° | 10.1° | 55.2mm | 11.6 | 77 |
| June | 24.2° | 13.6° | 52.2mm | 9.9 | 80 |
| July | 25.9° | 15.3° | 62.7mm | 11.5 | 77 |
| August | 25.7° | 15° | 52.2mm | 10.7 | 79 |
| September | 20.8° | 11.4° | 48.4mm | 9.4 | 81 |
| October | 14.8° | 7.7° | 51.5mm | 11.6 | 60 |
| November | 8.6° | 3.7° | 46.7mm | 11.9 | 40 |
| December | 5.2° | 0.9° | 51.3mm | 13.1 | 25 |
January in Mainz averages a daily high of 4.6°C with nights around 0°C. Expect roughly 12.6 wet days totalling 43.5mm. A hard month to visit for comfort alone.
February in Mainz averages a daily high of 6.8°C with nights around 0.6°C. Expect roughly 11.1 wet days totalling 40.1mm. A hard month to visit for comfort alone.
March in Mainz averages a daily high of 11.3°C with nights around 3.1°C. Expect roughly 11 wet days totalling 42.3mm. Demanding conditions — pack for it and plan indoor options.
April in Mainz averages a daily high of 16.3°C with nights around 6.3°C. Expect roughly 9.9 wet days totalling 37.8mm. Generally workable, with some weather to plan around.
May in Mainz averages a daily high of 20.3°C with nights around 10.1°C. Expect roughly 11.6 wet days totalling 55.2mm. Comfortable conditions for being outdoors all day.
June in Mainz averages a daily high of 24.2°C with nights around 13.6°C. Expect roughly 9.9 wet days totalling 52.2mm. Comfortable conditions for being outdoors all day.
July in Mainz averages a daily high of 25.9°C with nights around 15.3°C. Expect roughly 11.5 wet days totalling 62.7mm. Comfortable conditions for being outdoors all day.
August in Mainz averages a daily high of 25.7°C with nights around 15°C. Expect roughly 10.7 wet days totalling 52.2mm. Comfortable conditions for being outdoors all day.
September in Mainz averages a daily high of 20.8°C with nights around 11.4°C. Expect roughly 9.4 wet days totalling 48.4mm. Comfortable conditions for being outdoors all day.
October in Mainz averages a daily high of 14.8°C with nights around 7.7°C. Expect roughly 11.6 wet days totalling 51.5mm. Generally workable, with some weather to plan around.
November in Mainz averages a daily high of 8.6°C with nights around 3.7°C. Expect roughly 11.9 wet days totalling 46.7mm. Demanding conditions — pack for it and plan indoor options.
December in Mainz averages a daily high of 5.2°C with nights around 0.9°C. Expect roughly 13.1 wet days totalling 51.3mm. 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. Mainz peaks at 81.
Based on 30 years of records, May–September scores highest for comfort in Mainz, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 25.9°C.
July is the wettest, averaging 62.7mm of rain across roughly 11.5 wet days.
January is the coolest month, with average daily highs around 4.6°C.