The best time to visit Japan
The best time to visit Japan for warm, sunny weather is June to September, when its destinations average a Sunshine Score of 63/100 with daytime highs around 26°C / 79°F. May and October are quieter shoulder-season alternatives with still-reliable sun. The sea is swimmable (21°C+) about 5 months a year, warmest in August at 29°C.
Japan by month, averaged across 46 destinations from long-term climate normals — the best stretch is highlighted.
| Month | Sunshine Score | Avg day high | Rain | Sea | For a trip |
|---|---|---|---|---|---|
| January | 10 | 6° / 43°F | 86 mm | 13° | Poor |
| February | 13 | 8° / 46°F | 82 mm | 13° | Poor |
| March | 22 | 11° / 52°F | 105 mm | 12° | Poor |
| April | 42 | 16° / 61°F | 119 mm | 16° | Good |
| May | 59 | 21° / 70°F | 142 mm | 19° | Very good |
| June | 63 | 24° / 75°F | 208 mm | 22° | Very good |
| July | 63 | 27° / 81°F | 223 mm | 26° | Very good |
| August | 62 | 28° / 82°F | 171 mm | 29° | Very good |
| September | 62 | 25° / 77°F | 188 mm | 28° | Very good |
| October | 58 | 20° / 68°F | 143 mm | 24° | Very good |
| November | 38 | 15° / 59°F | 104 mm | 20° | Mixed |
| December | 16 | 9° / 48°F | 105 mm | 16° | Poor |
When to go — and when to think twice
Best overall: June to September — Japan's warmest, most reliable stretch (Sunshine Score 63/100, ~26°C / 79°F days). Shoulder season: May and October — quieter, still sunny. Hottest: August, ~28°C / 82°F. Wettest: July (223 mm) — pack for showers.
Where to base yourself for sunshine: Shizuoka (2,059 h/yr), Kochi (2,059 h/yr), Miyazaki (2,059 h/yr). See every Japan destination with a full climate card, or where it's sunny worldwide, month by month.