| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 7.2° | — | 100.2mm | 15.1 | 29 |
| February | 7.9° | — | 92.8mm | 13.5 | 34 |
| March | 12° | — | 112.6mm | 12.9 | 49 |
| April | 17.6° | — | 123.2mm | 11.8 | 69 |
| May | 22.8° | — | 136.1mm | 9.8 | 80 |
| June | 26.3° | — | 174.9mm | 11.9 | 76 |
| July | 30.6° | — | 231.1mm | 13.4 | 59 |
| August | 32.3° | — | 131.1mm | 9.5 | 60 |
| September | 27.9° | — | 164.7mm | 11.4 | 74 |
| October | 22° | — | 138.1mm | 9.7 | 81 |
| November | 15.9° | — | 90.5mm | 10.7 | 65 |
| December | 10.1° | — | 110.4mm | 14.9 | 39 |
January in Ōmihachiman averages a daily high of 7.2°C. Expect roughly 15.1 wet days totalling 100.2mm. A hard month to visit for comfort alone.
February in Ōmihachiman averages a daily high of 7.9°C. Expect roughly 13.5 wet days totalling 92.8mm. A hard month to visit for comfort alone.
March in Ōmihachiman averages a daily high of 12°C. Expect roughly 12.9 wet days totalling 112.6mm. Demanding conditions — pack for it and plan indoor options.
April in Ōmihachiman averages a daily high of 17.6°C. Expect roughly 11.8 wet days totalling 123.2mm. Generally workable, with some weather to plan around.
May in Ōmihachiman averages a daily high of 22.8°C. Expect roughly 9.8 wet days totalling 136.1mm. Comfortable conditions for being outdoors all day.
June in Ōmihachiman averages a daily high of 26.3°C. Expect roughly 11.9 wet days totalling 174.9mm. Comfortable conditions for being outdoors all day.
July in Ōmihachiman averages a daily high of 30.6°C. Expect roughly 13.4 wet days totalling 231.1mm. Generally workable, with some weather to plan around.
August in Ōmihachiman averages a daily high of 32.3°C. Expect roughly 9.5 wet days totalling 131.1mm. Generally workable, with some weather to plan around.
September in Ōmihachiman averages a daily high of 27.9°C. Expect roughly 11.4 wet days totalling 164.7mm. Generally workable, with some weather to plan around.
October in Ōmihachiman averages a daily high of 22°C. Expect roughly 9.7 wet days totalling 138.1mm. Comfortable conditions for being outdoors all day.
November in Ōmihachiman averages a daily high of 15.9°C. Expect roughly 10.7 wet days totalling 90.5mm. Generally workable, with some weather to plan around.
December in Ōmihachiman averages a daily high of 10.1°C. Expect roughly 14.9 wet days totalling 110.4mm. Demanding conditions — pack for it and plan indoor options.
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. Ōmihachiman peaks at 81.
Based on 30 years of records, May–June scores highest for comfort in Ōmihachiman, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 32.3°C.
July is the wettest, averaging 231.1mm of rain across roughly 13.4 wet days.
January is the coolest month, with average daily highs around 7.2°C.