South Korea · 30-year monthly climate averages
Based on 30 years of climate data, the most comfortable months to visit Jeju are April, May and October, when daytime temperatures are agreeable and rainfall is relatively low.
Jeju sees its warmest weather in August, when daytime highs average around 30°C, and its coolest in January (around 9°C).
Annual precipitation totals roughly 1502mm — August is typically the wettest month (~272mm) and December the driest (~56mm).
A distinctly wetter period runs from June to September — worth planning around if you prefer dry days.
May is the sunniest month, with about 212 hours of sunshine.
🟧 avg daytime high · 🟦 dashed: avg nighttime low · bars: monthly rainfall
Daily forecast highs vs the 30-year normal — last 60 days
Each bar is one day: orange above normal, blue below.
| Month | High / Low | Rainfall | Travel rating |
|---|---|---|---|
| January | 9° / 4°C | 68mm | 🤔 Fair |
| February | 10° / 4°C | 57mm | 🤔 Fair |
| March | 13° / 7°C | 91mm | 🤔 Fair |
| April | 18° / 11°C | 90mm | 👍 Good |
| May | 22° / 15°C | 96mm | 🌟 Great |
| June | 25° / 19°C | 171mm | 👍 Good |
| July | 29° / 24°C | 210mm | 🤔 Fair |
| August | 30° / 25°C | 272mm | ⚠️ Challenging |
| September | 26° / 21°C | 228mm | 🤔 Fair |
| October | 22° / 16°C | 95mm | 🌟 Great |
| November | 16° / 10°C | 70mm | 👍 Good |
| December | 11° / 6°C | 56mm | 🤔 Fair |
January in Jeju is chilly, with average daytime highs around 9°C (47°F) and nighttime lows near 4°C (39°F). Expect roughly 68mm of precipitation spread over about 8 rainy days, with a moderate amount of rain.
☀️ About 70 hours of sunshine over the month (~2h/day).
🎒 What to pack — jacket or coat · long-sleeve layers
February in Jeju is chilly, with average daytime highs around 10°C (50°F) and nighttime lows near 4°C (39°F). Expect roughly 57mm of precipitation spread over about 7 rainy days, with little rainfall.
☀️ About 110 hours of sunshine over the month (~4h/day).
🎒 What to pack — jacket or coat · long-sleeve layers
March in Jeju is chilly, with average daytime highs around 13°C (56°F) and nighttime lows near 7°C (44°F). Expect roughly 91mm of precipitation spread over about 8 rainy days, with a moderate amount of rain.
☀️ About 166 hours of sunshine over the month (~6h/day).
🎒 What to pack — jacket or coat · long-sleeve layers
April in Jeju is mild, with average daytime highs around 18°C (64°F) and nighttime lows near 11°C (51°F). Expect roughly 90mm of precipitation spread over about 8 rainy days, with a moderate amount of rain.
☀️ About 197 hours of sunshine over the month (~7h/day).
🎒 What to pack — light jacket · layers for cool evenings
May in Jeju is pleasantly warm, with average daytime highs around 22°C (72°F) and nighttime lows near 15°C (59°F). Expect roughly 96mm of precipitation spread over about 7 rainy days, with a moderate amount of rain.
☀️ About 212 hours of sunshine over the month (~7h/day).
🎒 What to pack — light layers · comfortable walking shoes
June in Jeju is pleasantly warm, with average daytime highs around 25°C (77°F) and nighttime lows near 19°C (66°F). Expect roughly 171mm of precipitation spread over about 9 rainy days, and this is one of the wetter months.
☀️ About 160 hours of sunshine over the month (~5h/day).
🎒 What to pack — light layers · comfortable walking shoes · compact umbrella or rain jacket
July in Jeju is warm, with average daytime highs around 29°C (85°F) and nighttime lows near 24°C (75°F). Expect roughly 210mm of precipitation spread over about 9 rainy days, and heavy rainfall is common — this is peak wet season territory.
☀️ About 190 hours of sunshine over the month (~6h/day).
🎒 What to pack — light summer clothing · sunscreen and sunglasses · compact umbrella or rain jacket
August in Jeju is hot, with average daytime highs around 30°C (86°F) and nighttime lows near 25°C (77°F). Expect roughly 272mm of precipitation spread over about 10 rainy days, and heavy rainfall is common — this is peak wet season territory.
☀️ About 195 hours of sunshine over the month (~7h/day).
🎒 What to pack — breathable summer clothing · sunscreen, hat and sunglasses · refillable water bottle · compact umbrella or rain jacket
September in Jeju is warm, with average daytime highs around 26°C (79°F) and nighttime lows near 21°C (70°F). Expect roughly 228mm of precipitation spread over about 8 rainy days, and heavy rainfall is common — this is peak wet season territory.
☀️ About 159 hours of sunshine over the month (~5h/day).
🎒 What to pack — light summer clothing · sunscreen and sunglasses · compact umbrella or rain jacket
October in Jeju is pleasantly warm, with average daytime highs around 22°C (71°F) and nighttime lows near 16°C (60°F). Expect roughly 95mm of precipitation spread over about 5 rainy days, with a moderate amount of rain.
☀️ About 173 hours of sunshine over the month (~6h/day).
🎒 What to pack — light layers · comfortable walking shoes
November in Jeju is mild, with average daytime highs around 16°C (62°F) and nighttime lows near 10°C (51°F). Expect roughly 70mm of precipitation spread over about 7 rainy days, with a moderate amount of rain.
☀️ About 124 hours of sunshine over the month (~4h/day).
🎒 What to pack — light jacket · layers for cool evenings
December in Jeju is chilly, with average daytime highs around 11°C (52°F) and nighttime lows near 6°C (42°F). Expect roughly 56mm of precipitation spread over about 8 rainy days, with little rainfall.
☀️ About 79 hours of sunshine over the month (~3h/day).
🎒 What to pack — jacket or coat · long-sleeve layers