| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 9.9° | — | 35.5mm | 5.4 | 57 |
| February | 10.9° | — | 58.3mm | 7.4 | 56 |
| March | 14.3° | — | 91.3mm | 9.7 | 62 |
| April | 19.5° | — | 111.4mm | 9.4 | 80 |
| May | 24.2° | — | 143.4mm | 9.6 | 81 |
| June | 26.8° | — | 206.2mm | 13.5 | 73 |
| July | 30.7° | — | 182.7mm | 12.1 | 61 |
| August | 32.5° | — | 181.9mm | 9.6 | 59 |
| September | 28.7° | — | 218.3mm | 11.5 | 70 |
| October | 23.3° | — | 181.9mm | 9.6 | 81 |
| November | 17.7° | — | 107.8mm | 7.6 | 77 |
| December | 12.6° | — | 52.7mm | 6.4 | 64 |
January in Narutochō-mitsuishi averages a daily high of 9.9°C. Expect roughly 5.4 wet days totalling 35.5mm. Generally workable, with some weather to plan around.
February in Narutochō-mitsuishi averages a daily high of 10.9°C. Expect roughly 7.4 wet days totalling 58.3mm. Generally workable, with some weather to plan around.
March in Narutochō-mitsuishi averages a daily high of 14.3°C. Expect roughly 9.7 wet days totalling 91.3mm. Generally workable, with some weather to plan around.
April in Narutochō-mitsuishi averages a daily high of 19.5°C. Expect roughly 9.4 wet days totalling 111.4mm. Comfortable conditions for being outdoors all day.
May in Narutochō-mitsuishi averages a daily high of 24.2°C. Expect roughly 9.6 wet days totalling 143.4mm. Comfortable conditions for being outdoors all day.
June in Narutochō-mitsuishi averages a daily high of 26.8°C. Expect roughly 13.5 wet days totalling 206.2mm. Generally workable, with some weather to plan around.
July in Narutochō-mitsuishi averages a daily high of 30.7°C. Expect roughly 12.1 wet days totalling 182.7mm. Generally workable, with some weather to plan around.
August in Narutochō-mitsuishi averages a daily high of 32.5°C. Expect roughly 9.6 wet days totalling 181.9mm. Generally workable, with some weather to plan around.
September in Narutochō-mitsuishi averages a daily high of 28.7°C. Expect roughly 11.5 wet days totalling 218.3mm. Generally workable, with some weather to plan around.
October in Narutochō-mitsuishi averages a daily high of 23.3°C. Expect roughly 9.6 wet days totalling 181.9mm. Comfortable conditions for being outdoors all day.
November in Narutochō-mitsuishi averages a daily high of 17.7°C. Expect roughly 7.6 wet days totalling 107.8mm. Comfortable conditions for being outdoors all day.
December in Narutochō-mitsuishi averages a daily high of 12.6°C. Expect roughly 6.4 wet days totalling 52.7mm. 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. Narutochō-mitsuishi peaks at 81.
Based on 30 years of records, April–June scores highest for comfort in Narutochō-mitsuishi, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 32.5°C.
September is the wettest, averaging 218.3mm of rain across roughly 11.5 wet days.
January is the coolest month, with average daily highs around 9.9°C.