Izu Oshima weather by month & the best time to visit
Japan · major coastal city · humid subtropical climate
The best time to visit Izu Oshima is May — its sunniest month (Sunshine Score 62/100), with June and July close behind. Izu Oshima averages about 1,871 hours of sunshine a year. Daytime highs around 20°C / 68°F and roughly 175 mm of rain in May.
When is the best time to visit Izu Oshima?
For sunshine, the best time to visit Izu Oshima is May, then June and July. The dullest month is February (18/100, 92 mm of rain). The full month-by-month picture is in the table below.
How sunny is Izu Oshima?
Izu Oshima gets a moderate 1,871 hours of sunshine a year. May (62/100) is noticeably better than February (18). It ranks #18 of 79 destinations in Japan for annual sunshine, above the national median of 1,773 hours. The year's 1,946 mm of rain spreads fairly evenly across the months, with no pronounced dry season.
Sunshine Score by month
| Month | Score | Day high | Night low | Rain | UV | Sea |
|---|---|---|---|---|---|---|
| January | 19 | 11° / 52°F | 7° / 45°F | 84 mm | 2 | 20° / 68°F |
| February | 18 | 11° / 52°F | 7° / 45°F | 92 mm | 3 | 19° / 66°F |
| March | 31 | 14° / 57°F | 9° / 48°F | 146 mm | 4 | 18° / 64°F |
| April | 47 | 17° / 63°F | 13° / 55°F | 163 mm | 5 | 20° / 68°F |
| May | 62 | 20° / 68°F | 17° / 63°F | 175 mm | 6 | 21° / 70°F |
| June | 62 | 23° / 73°F | 20° / 68°F | 225 mm | 6 | 24° / 75°F |
| July | 62 | 26° / 79°F | 23° / 73°F | 201 mm | 7 | 27° / 81°F |
| August | 62 | 28° / 82°F | 25° / 77°F | 160 mm | 8 | 30° / 86°F |
| September | 62 | 26° / 79°F | 23° / 73°F | 233 mm | 6 | 29° / 84°F |
| October | 62 | 22° / 72°F | 18° / 64°F | 251 mm | 4 | 27° / 81°F |
| November | 55 | 18° / 64°F | 14° / 57°F | 127 mm | 3 | 24° / 75°F |
| December | 31 | 13° / 55°F | 9° / 48°F | 89 mm | 2 | 21° / 70°F |
Sea temperature in Izu Oshima by month
The sea off Izu Oshima is warmest in August at around 30°C / 86°F, and coolest in March at 18°C / 64°F. The water sits at a comfortable 21°C or warmer roughly 8 months a year. Month-by-month sea-surface temperatures are in the Sea column of the table above.
Nearest destinations
Izu Oshima: questions and answers
What kind of destination is Izu Oshima?
Izu Oshima is a major coastal city in Japan with a humid subtropical climate — the sea reaches 30°C at its warmest and is swimmable (21°C+) about 8 months a year.
How many hours of sunshine does Izu Oshima get a year?
Izu Oshima gets about 1,871 hours of sunshine a year, at its best around May.
When is the best time to visit Izu Oshima?
The sunniest time to visit Izu Oshima is May, when the Sunshine Score peaks at 62/100 (with June and July close behind). Expect daytime highs around 20°C / 68°F.
What is the least sunny month in Izu Oshima?
February is the least sunny month in Izu Oshima, scoring 18/100 with about 92 mm of rain.
What is the sea temperature in Izu Oshima?
The sea in Izu Oshima ranges from about 18°C (March) to 30°C (August). Month-by-month sea temperatures are on this page.
How strong is the sun in Izu Oshima?
The typical midday UV index in Izu Oshima peaks around 8 (very high) in August, easing to about 2 (low) in January. Month-by-month midday UV values are in the UV column of the table on this page.
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