Verdict: Fair month
Jeju Weather in December
December is properly cold in Jeju, with highs of only 9°C (48°F). It's also the wet side of the calendar: rain falls on about 15 days, so build flexibility into plans. December is workable in Jeju if your dates are fixed — just plan around the conditions.
Average high
9°C / 48°F
Average low
5°C / 41°F
Rain days
~15
Precipitation
86 mm
What to pack for Jeju in December
- A proper warm jacket, and a hat for mornings
- Rain gear is non-negotiable — expect rain on roughly 15 days
- Comfortable walking shoes — every guide on this site assumes you'll use them
December against the rest of the year
Warmest in Jeju: Aug (30°C / 86°F) · Coolest: Jan (8°C / 46°F) · Wettest: Jul (~20 rain days)
8°
3°
Jan
10°
4°
Feb
14°
7°
Mar
17°
11°
Apr
22°
15°
May
25°
20°
Jun
29°
24°
Jul
30°
25°
Aug
26°
22°
Sep
21°
16°
Oct
16°
11°
Nov
9°
5°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)