| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 4.4° | -0.4° | 64.5mm | 15.4 | 16 |
| February | 6.8° | 0.4° | 55.3mm | 14.2 | 27 |
| March | 10.9° | 2.2° | 53mm | 12.6 | 46 |
| April | 15.6° | 4.9° | 44.8mm | 11.1 | 64 |
| May | 19.7° | 8.7° | 68.8mm | 13 | 73 |
| June | 23.5° | 11.9° | 61.7mm | 11.5 | 77 |
| July | 25.2° | 13.6° | 75.3mm | 12.7 | 75 |
| August | 25° | 13.5° | 63.8mm | 12.3 | 75 |
| September | 20.7° | 10.1° | 59.6mm | 10.1 | 80 |
| October | 15.2° | 7.2° | 67.8mm | 13.4 | 58 |
| November | 8.7° | 3.4° | 63.6mm | 15.7 | 34 |
| December | 5.2° | 0.7° | 71.6mm | 16.3 | 21 |
January in Trier averages a daily high of 4.4°C with nights around -0.4°C. Expect roughly 15.4 wet days totalling 64.5mm. A hard month to visit for comfort alone.
February in Trier averages a daily high of 6.8°C with nights around 0.4°C. Expect roughly 14.2 wet days totalling 55.3mm. A hard month to visit for comfort alone.
March in Trier averages a daily high of 10.9°C with nights around 2.2°C. Expect roughly 12.6 wet days totalling 53mm. Demanding conditions — pack for it and plan indoor options.
April in Trier averages a daily high of 15.6°C with nights around 4.9°C. Expect roughly 11.1 wet days totalling 44.8mm. Generally workable, with some weather to plan around.
May in Trier averages a daily high of 19.7°C with nights around 8.7°C. Expect roughly 13 wet days totalling 68.8mm. Generally workable, with some weather to plan around.
June in Trier averages a daily high of 23.5°C with nights around 11.9°C. Expect roughly 11.5 wet days totalling 61.7mm. Comfortable conditions for being outdoors all day.
July in Trier averages a daily high of 25.2°C with nights around 13.6°C. Expect roughly 12.7 wet days totalling 75.3mm. Comfortable conditions for being outdoors all day.
August in Trier averages a daily high of 25°C with nights around 13.5°C. Expect roughly 12.3 wet days totalling 63.8mm. Comfortable conditions for being outdoors all day.
September in Trier averages a daily high of 20.7°C with nights around 10.1°C. Expect roughly 10.1 wet days totalling 59.6mm. Comfortable conditions for being outdoors all day.
October in Trier averages a daily high of 15.2°C with nights around 7.2°C. Expect roughly 13.4 wet days totalling 67.8mm. Generally workable, with some weather to plan around.
November in Trier averages a daily high of 8.7°C with nights around 3.4°C. Expect roughly 15.7 wet days totalling 63.6mm. A hard month to visit for comfort alone.
December in Trier averages a daily high of 5.2°C with nights around 0.7°C. Expect roughly 16.3 wet days totalling 71.6mm. 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. Trier peaks at 80.
Based on 30 years of records, May–September scores highest for comfort in Trier, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 25.2°C.
July is the wettest, averaging 75.3mm of rain across roughly 12.7 wet days.
January is the coolest month, with average daily highs around 4.4°C.