Hiroshima vs Karuizawa: which is better, month by month

Hiroshima beats Karuizawa in 8 of 12 months — its lead peaks in October (87 vs 66) — while Karuizawa wins June to September.

Each place is scored under the lens that suits its type. Comfort is SeasonMap's 0–100 estimate from ERA5 climate normals, not a forecast.

Hiroshima

🇯🇵 Japan · mild climate

Best month: October 87/100
Months won: 8 of 12

Karuizawa

🇯🇵 Japan · mild climate

Best month: May 79/100
Months won: 4 of 12

Hiroshima vs Karuizawa — all 12 months

Month	Hiroshima	Karuizawa	Winner	Gap
January	67Ccold, a little rain, clean air	51Dfreezing, a little rain, clean air	Hiroshima	16
February	70Bcold, a little rain, clean air	54Dfreezing, a little rain, clean air	Hiroshima	16
March	74Bcool, rainy	63Ccold, rainy, reliable snow	Hiroshima	11
April	81Anice, rainy	73Bcool, rainy	Hiroshima	8
May	86Awarm, rainy, muggy air	79Bnice, rainy, muggy air	Hiroshima	7
June	68Chot, soaked, muggy air	77Bnice, soaked, muggy air	Karuizawa	9
July	53Dsweltering, soaked, clean air	71Bhot, soaked, clean air	Karuizawa	18
August	56Dsweltering, soaked, clean air	75Bhot, soaked, clean air	Karuizawa	19
September	63Chot, soaked, clean air	78Bnice, soaked, clean air	Karuizawa	15
October	87Awarm, rainy, clean air	66Ccool, soaked, clean air	Hiroshima	21
November	83Anice, a little rain, clean air	69Ccold, a little rain, clean air	Hiroshima	14
December	71Bcold, a little rain, clean air	58Dcold, a little rain, clean air	Hiroshima	13

A month is a tie when the two are within 3 points. The widest gap is October (87 vs 66). Tap a month for that month's temperature, rain, humidity and air quality side by side.