| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 4.5° | -1.2° | 36.6mm | 14.4 | 17 |
| February | 6.8° | -0.6° | 34.1mm | 12.4 | 29 |
| March | 10.7° | 1.4° | 40mm | 12.9 | 44 |
| April | 16° | 4.4° | 35.9mm | 10.3 | 67 |
| May | 20.5° | 8.5° | 60.4mm | 12.3 | 75 |
| June | 24.2° | 12.2° | 50.9mm | 12.2 | 76 |
| July | 26° | 14° | 83mm | 12.8 | 74 |
| August | 25.8° | 13.6° | 70.7mm | 12.1 | 76 |
| September | 21° | 10.1° | 54.3mm | 10.8 | 78 |
| October | 15.5° | 6.6° | 42.7mm | 12 | 62 |
| November | 9.1° | 2.8° | 46.7mm | 12.6 | 40 |
| December | 5.3° | -0.1° | 41.4mm | 14.7 | 20 |
January in Jena averages a daily high of 4.5°C with nights around -1.2°C. Expect roughly 14.4 wet days totalling 36.6mm. A hard month to visit for comfort alone.
February in Jena averages a daily high of 6.8°C with nights around -0.6°C. Expect roughly 12.4 wet days totalling 34.1mm. A hard month to visit for comfort alone.
March in Jena averages a daily high of 10.7°C with nights around 1.4°C. Expect roughly 12.9 wet days totalling 40mm. Demanding conditions — pack for it and plan indoor options.
April in Jena averages a daily high of 16°C with nights around 4.4°C. Expect roughly 10.3 wet days totalling 35.9mm. Generally workable, with some weather to plan around.
May in Jena averages a daily high of 20.5°C with nights around 8.5°C. Expect roughly 12.3 wet days totalling 60.4mm. Comfortable conditions for being outdoors all day.
June in Jena averages a daily high of 24.2°C with nights around 12.2°C. Expect roughly 12.2 wet days totalling 50.9mm. Comfortable conditions for being outdoors all day.
July in Jena averages a daily high of 26°C with nights around 14°C. Expect roughly 12.8 wet days totalling 83mm. Generally workable, with some weather to plan around.
August in Jena averages a daily high of 25.8°C with nights around 13.6°C. Expect roughly 12.1 wet days totalling 70.7mm. Comfortable conditions for being outdoors all day.
September in Jena averages a daily high of 21°C with nights around 10.1°C. Expect roughly 10.8 wet days totalling 54.3mm. Comfortable conditions for being outdoors all day.
October in Jena averages a daily high of 15.5°C with nights around 6.6°C. Expect roughly 12 wet days totalling 42.7mm. Generally workable, with some weather to plan around.
November in Jena averages a daily high of 9.1°C with nights around 2.8°C. Expect roughly 12.6 wet days totalling 46.7mm. Demanding conditions — pack for it and plan indoor options.
December in Jena averages a daily high of 5.3°C with nights around -0.1°C. Expect roughly 14.7 wet days totalling 41.4mm. 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. Jena peaks at 78.
Based on 30 years of records, May–September scores highest for comfort in Jena, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 26°C.
July is the wettest, averaging 83mm of rain across roughly 12.8 wet days.
January is the coolest month, with average daily highs around 4.5°C.