| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 9.1° | — | 24.5mm | 3 | 59 |
| February | 10.1° | — | 36.7mm | 4.8 | 59 |
| March | 13.9° | — | 75mm | 8.4 | 64 |
| April | 19.5° | — | 89.9mm | 8.6 | 81 |
| May | 24.2° | — | 105.9mm | 9.8 | 80 |
| June | 26.5° | — | 165.1mm | 13.9 | 72 |
| July | 30.2° | — | 178.8mm | 14.9 | 57 |
| August | 31.5° | — | 169.1mm | 12.6 | 57 |
| September | 26.7° | — | 217.8mm | 12.7 | 75 |
| October | 21.2° | — | 160mm | 10.5 | 79 |
| November | 16.2° | — | 49.2mm | 5.3 | 77 |
| December | 11.3° | — | 34.5mm | 4.1 | 64 |
January in Chichibu averages a daily high of 9.1°C. Expect roughly 3 wet days totalling 24.5mm. Generally workable, with some weather to plan around.
February in Chichibu averages a daily high of 10.1°C. Expect roughly 4.8 wet days totalling 36.7mm. Generally workable, with some weather to plan around.
March in Chichibu averages a daily high of 13.9°C. Expect roughly 8.4 wet days totalling 75mm. Generally workable, with some weather to plan around.
April in Chichibu averages a daily high of 19.5°C. Expect roughly 8.6 wet days totalling 89.9mm. Comfortable conditions for being outdoors all day.
May in Chichibu averages a daily high of 24.2°C. Expect roughly 9.8 wet days totalling 105.9mm. Comfortable conditions for being outdoors all day.
June in Chichibu averages a daily high of 26.5°C. Expect roughly 13.9 wet days totalling 165.1mm. Generally workable, with some weather to plan around.
July in Chichibu averages a daily high of 30.2°C. Expect roughly 14.9 wet days totalling 178.8mm. Generally workable, with some weather to plan around.
August in Chichibu averages a daily high of 31.5°C. Expect roughly 12.6 wet days totalling 169.1mm. Generally workable, with some weather to plan around.
September in Chichibu averages a daily high of 26.7°C. Expect roughly 12.7 wet days totalling 217.8mm. Comfortable conditions for being outdoors all day.
October in Chichibu averages a daily high of 21.2°C. Expect roughly 10.5 wet days totalling 160mm. Comfortable conditions for being outdoors all day.
November in Chichibu averages a daily high of 16.2°C. Expect roughly 5.3 wet days totalling 49.2mm. Comfortable conditions for being outdoors all day.
December in Chichibu averages a daily high of 11.3°C. Expect roughly 4.1 wet days totalling 34.5mm. 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. Chichibu peaks at 81.
Based on 30 years of records, September–November scores highest for comfort in Chichibu, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 31.5°C.
September is the wettest, averaging 217.8mm of rain across roughly 12.7 wet days.
January is the coolest month, with average daily highs around 9.1°C.