Iwakuni weather by month & the best time to visit
Japan · beach resort · humid subtropical climate
The best time to visit Iwakuni is October — its sunniest month (Sunshine Score 67/100), with August and May close behind. Iwakuni averages about 1,773 hours of sunshine a year. Daytime highs around 23°C / 73°F and roughly 119 mm of rain in October.
When is the best time to visit Iwakuni?
For sunshine, the best time to visit Iwakuni is October, then August and May. The dullest month is January (7/100, 56 mm of rain). The full month-by-month picture is in the table below.
How sunny is Iwakuni?
Iwakuni isn't a sunny place by world standards: about 1,773 hours of sunshine a year. 60 Sunshine Score points separate October (67) from January (7), so the month you pick matters. It ranks #41 of 79 destinations in Japan for annual sunshine, right at the national median of 1,773 hours. Rain has a clear season: the wettest stretch, around June, carries about 41% of the annual 1,621 mm.
Sunshine Score by month
| Month | Score | Day high | Night low | Rain | UV | Sea |
|---|---|---|---|---|---|---|
| January | 7 | 9° / 48°F | 4° / 39°F | 56 mm | 2 | 14° / 57°F |
| February | 19 | 11° / 52°F | 5° / 41°F | 76 mm | 3 | 12° / 54°F |
| March | 34 | 14° / 57°F | 7° / 45°F | 109 mm | 4 | 12° / 54°F |
| April | 55 | 18° / 64°F | 11° / 52°F | 128 mm | 5 | 16° / 61°F |
| May | 61 | 22° / 72°F | 15° / 59°F | 153 mm | 6 | 18° / 64°F |
| June | 61 | 25° / 77°F | 20° / 68°F | 242 mm | 6 | 22° / 72°F |
| July | 61 | 28° / 82°F | 24° / 75°F | 268 mm | 7 | 26° / 79°F |
| August | 64 | 30° / 86°F | 25° / 77°F | 138 mm | 7 | 30° / 86°F |
| September | 61 | 27° / 81°F | 22° / 72°F | 181 mm | 6 | 28° / 82°F |
| October | 67 | 23° / 73°F | 17° / 63°F | 119 mm | 4 | 24° / 75°F |
| November | 56 | 17° / 63°F | 12° / 54°F | 77 mm | 3 | 21° / 70°F |
| December | 25 | 12° / 54°F | 7° / 45°F | 74 mm | 2 | 16° / 61°F |
Sea temperature in Iwakuni by month
The sea off Iwakuni is warmest in August at around 30°C / 86°F, and coolest in February at 12°C / 54°F. The water sits at a comfortable 21°C or warmer roughly 6 months a year. Month-by-month sea-surface temperatures are in the Sea column of the table above.
Nearest destinations
Head-to-head
How Iwakuni compares month by month: Iwakuni vs Hiroshima · Iwakuni vs Matsuyama · Iwakuni vs Oita · all comparisons
Iwakuni: questions and answers
What kind of destination is Iwakuni?
Iwakuni is a beach resort in Japan with a humid subtropical climate — the sea reaches 30°C at its warmest and is swimmable (21°C+) about 6 months a year.
How many hours of sunshine does Iwakuni get a year?
Iwakuni gets about 1,773 hours of sunshine a year, at its best around October.
When is the best time to visit Iwakuni?
The sunniest time to visit Iwakuni is October, when the Sunshine Score peaks at 67/100 (with August and May close behind). Expect daytime highs around 23°C / 73°F.
What is the least sunny month in Iwakuni?
January is the least sunny month in Iwakuni, scoring 7/100 with about 56 mm of rain.
What is the sea temperature in Iwakuni?
The sea in Iwakuni ranges from about 12°C (February) to 30°C (August). Month-by-month sea temperatures are on this page.
How strong is the sun in Iwakuni?
The typical midday UV index in Iwakuni peaks around 7 (high) in July, 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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