| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 10.7° | — | 54.2mm | 6.5 | 57 |
| February | 12.7° | — | 94.8mm | 8.6 | 59 |
| March | 16.4° | — | 118.2mm | 11 | 66 |
| April | 21.6° | — | 137.1mm | 10.2 | 80 |
| May | 26.2° | — | 179.8mm | 9.9 | 80 |
| June | 28.5° | — | 402.6mm | 14.9 | 64 |
| July | 31.9° | — | 378.5mm | 13.7 | 53 |
| August | 33.4° | — | 233mm | 12.6 | 49 |
| September | 30.3° | — | 167.7mm | 10 | 67 |
| October | 25.2° | — | 92.1mm | 6.6 | 87 |
| November | 19° | — | 79.3mm | 8.2 | 80 |
| December | 12.8° | — | 61.7mm | 8.4 | 60 |
January in Kumamoto averages a daily high of 10.7°C. Expect roughly 6.5 wet days totalling 54.2mm. Generally workable, with some weather to plan around.
February in Kumamoto averages a daily high of 12.7°C. Expect roughly 8.6 wet days totalling 94.8mm. Generally workable, with some weather to plan around.
March in Kumamoto averages a daily high of 16.4°C. Expect roughly 11 wet days totalling 118.2mm. Generally workable, with some weather to plan around.
April in Kumamoto averages a daily high of 21.6°C. Expect roughly 10.2 wet days totalling 137.1mm. Comfortable conditions for being outdoors all day.
May in Kumamoto averages a daily high of 26.2°C. Expect roughly 9.9 wet days totalling 179.8mm. Comfortable conditions for being outdoors all day.
June in Kumamoto averages a daily high of 28.5°C. Expect roughly 14.9 wet days totalling 402.6mm. Generally workable, with some weather to plan around.
July in Kumamoto averages a daily high of 31.9°C. Expect roughly 13.7 wet days totalling 378.5mm. Demanding conditions — pack for it and plan indoor options.
August in Kumamoto averages a daily high of 33.4°C. Expect roughly 12.6 wet days totalling 233mm. Demanding conditions — pack for it and plan indoor options.
September in Kumamoto averages a daily high of 30.3°C. Expect roughly 10 wet days totalling 167.7mm. Generally workable, with some weather to plan around.
October in Kumamoto averages a daily high of 25.2°C. Expect roughly 6.6 wet days totalling 92.1mm. Comfortable conditions for being outdoors all day.
November in Kumamoto averages a daily high of 19°C. Expect roughly 8.2 wet days totalling 79.3mm. Comfortable conditions for being outdoors all day.
December in Kumamoto averages a daily high of 12.8°C. Expect roughly 8.4 wet days totalling 61.7mm. Generally workable, with some weather to plan around.
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. Kumamoto peaks at 87.
Based on 30 years of records, April–May scores highest for comfort in Kumamoto, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 33.4°C.
June is the wettest, averaging 402.6mm of rain across roughly 14.9 wet days.
January is the coolest month, with average daily highs around 10.7°C.