Mornings sit near the overnight low around 26°C with clear, cooler light — best for outdoor photos before crowds build.
Jeju Weather in September
Everything you need to know about Jeju weather in September
Updated September 10, 2026
Korea · Jeju
Jeju Weather in September
September in Jeju is hot, humid and energetically busy. Expect daytime highs around 33°C (91°F), mild nights around 26°C, long sunny stretches, and a calmer pace than peak season Check the full climate tables below for monthly averages and packing cues.
- Avg high / low
- 33°C / 26°C
- 91F / 79F
- Precipitation
- 80mm
- 10 wet days
- Daylight
- 12.5 hrs
- mid-range daylight
Jeju average temperatures through the year
SeptemberRest of the year
21°
22°
25°
28°
31°
33°
35°
35°
33°
29°
25°
22°
JAN
5 wet
FEB
6 wet
MAR
8 wet
APR
9 wet
MAY
12 wet
JUN
14 wet
JUL
12 wet
AUG
13 wet
SEP
10 wet
OCT
6 wet
NOV
5 wet
DEC
4 wet
Daytime highs in Celsius with wet days per month for Jeju. September sits at 33°C with 10 wet days.
The short answer
September falls in Jeju's autumn. Daytime highs average 33°C (91°F) with nights near 26°C (79°F). Precipitation totals about 80mm across roughly 10 wet days. Settling snow is uncommon. Visiting works with flexible outdoor plans and a packing buffer Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
September climate in Jeju
Monthly averages for Jeju, Korea.
- Day high
- 33°C
- 91°F
- Night low
- 26°C
- 79°F
- Precipitation
- 80mm
- 3.1 in
- Wet days
- 10
- rain or drizzle
- Sunrise
- 5:45am
- mid-September
- Sunset
- 6:15pm
- mid-range daylight
- Daylight
- 12.5 hrs
- 7 hrs sunshine
Averages based on long-run monthly climate normals. Last updated September 10, 2026.
Real weeks swing around the 30°C mean. Early September often sits near 32°C while the final week lands closer to 34°C. Pack a spare layer for that 1° drift rather than dressing only for the monthly average Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
Rain and drizzle usually arrive in pulses across the 10 wet days. Dry stretches between systems feel clearer and colder overnight. Use those gaps for outdoor sightseeing and keep indoor backups for the wetter clusters Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
What is the average temperature in Jeju in September?
The average temperature in Jeju in September is around 30°C (86°F), combining daytime highs of 33°C (91°F) with night lows of 26°C (79°F). The month warms steadily: the first days average highs near 32°C, while the final week typically tops out around 34°C with nights of 27°C.
Average daily high and low through September. The month warms by roughly 1 degrees start to finish.
How much does it rain in Jeju in September?
Jeju gets around 80mm (3.1in) of precipitation in September, spread over roughly 10 wet days. Wet spells typically last a day or two and clear to drier stretches in between Check the full climate tables below for monthly averages and packing cues.
40
48
64
72
96
112
96
104
80
48
40
32
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
Average precipitation by month in millimetres. September's 80mm sits near the annual rhythm.
Average precipitation by hour of day in Jeju
September precipitation in Jeju falls fairly evenly around the clock, with a mild overnight and early-morning peak. There is no predictable afternoon-downpour pattern — check the day's forecast rather than timing outings by the clock Check the full climate tables below for monthly averages and packing cues.
12am6am12pm6pm12am
Relative share of September precipitation by hour of day. The distribution is fairly flat, with a mild overnight peak.
When is sunrise and sunset in Jeju in September?
September daylight in Jeju averages about 12.5 hours, mid-range daylight. Sunrise drifts from 5:45am to 5:51am across the month, while sunset holds near 6:15pm before edging toward 6:19pm. Plan outdoor sightseeing in the brighter midday window Check the full climate tables below for monthly averages and packing cues.
Sunrise and sunset through September. The shaded band is daylight Check the full climate tables below for monthly averages and packing cues.
How humid is Jeju in September?
Relative humidity in Jeju in September averages around 76 percent. At 33°C that reads damper than the thermometer suggests. Temperature and wind still drive packing more than humidity alone Check the full climate tables below for monthly averages and packing cues.
68
70
72
75
78
82
80
80
76
70
68
66
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
Average relative humidity by month. September sits near 76%.
What is the weather like in Jeju the rest of the year?
Jeju moves from cooler months near 21°C highs through a warmer peak near 35°C. The best-weather stretch usually aligns with January and February. September sits in the autumn arc with 33°C highs Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
Average high (coral) and low (navy) by month. The shaded band is the typical daily range; SEP is marked.
Is September a good time to visit Jeju?
Depends — weather works with flexible plans. Here is the honest trade-off.
OverallSolid with flexible plans
WeatherHot and humid
CrowdsMedium
PricesMid
Budget (per night)$140 to $220
Book ahead3 to 5 weeks
September in Jeju is defined by still warm, easing rains and 33°C days. Stays often land in the $140–$220 range with mid season demand. The smartest move is to book about 3–5 weeks ahead and keep outdoor blocks in the brighter midday window Check the full climate tables below for monthly averages and packing cues.
Pros
- 33°C highs suit warm days in Jeju
- 7h average sunshine for daytime plans
- Medium crowds shape the September pace
- Mid season rates for stays and flights
Cons
- 10 wet days can pause outdoor sightseeing
- Humidity at 76% can feel heavier than the air temp
- Some attractions keep shorter winter hours
- Daylight near 12.5 hrs shortens evening walks
Travelling to Jeju in September?
Book lodgings about 3–5 weeks ahead, then visit the busiest central sights right at opening on a weekday to skip the mid-afternoon crush first-timers always hit Check the full climate tables below for monthly averages and packing cues. Compare months on our Best Time to Visit Jeju guide.
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What September actually feels like
September is Jeju's autumn in lived terms: still warm, easing rains. Most days feel cold, dry and often clear, with damper grey stretches arriving in bursts rather than settling in for the whole month Check the full climate tables below for monthly averages and packing cues.
The underestimated variable is clustered wet days. It truncates outdoor evenings and pushes dinner earlier. Build one indoor spare block every day Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
Early September often starts near 32°C while the final week trends toward 34°C. That 1° drift is enough to change coat weight mid-trip. Recheck the forecast before packing day seven Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
Afternoons reach 33–34°C before an early sunset near the 12.5-hour daylight limit — plan open-air stops then.
Evenings cool quickly toward 26°C; shift to indoor dining and illuminated streets once the light drops.
September in Jeju, week by week
Crowds and prices move more than the thermometer.
September 1–7
32°C (90°F)- Crowds
- Medium
- Prices
- Mid season
- Best for
- Quieter weekday exploring
September 8–14
33°C (91°F)- Crowds
- Medium
- Prices
- Mid season
- Best for
- Balanced weather window
September 15–21
33°C (91°F)- Crowds
- Medium
- Prices
- Mid season
- Best for
- Steady mid-month pace
September 22–30
34°C (93°F)- Crowds
- Medium
- Prices
- Mid season
- Best for
- Late-month flexible plans
Temperatures are Jeju monthly averages split across each window. Individual years vary by several degrees.
What to pack and wear for Jeju in September
Light fabric, serious sun care
Pack for Jeju in September around the 33°C / 26°C swing. The governing rule is ventilate and block UV. The one item worth buying before you fly is a compact rain shell Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
Essential
- Breathable shirts
- Sun hat
- SPF 50+ sunscreen
- Refillable bottle
Smart additions
- Packable rain shell
- Quick-dry trousers
- Zip pouch for maps
- Thin gloves
Leave behind
- Thick parkas
- Wool sweaters
- Snow boots
Top places to visit in Jeju in September
Outdoor icons with shade breaks
City centre · Free
Jeju landmark walk
Go early on weekdays for quieter photos and softer light.
Add to your planWaterfront · Free
Harbour or river promenade
Golden hour is the calmest window Check the full climate tables below for monthly averages and packing cues.
Add to your planMuseum quarter · Paid
Flagship museum morning
Weekday openings beat weekend queues and wet-day backups.
Add to your planOld town · Free
Historic streets loop
Late morning light helps cold stone feel less harsh.
Add to your planPark · Free
Central green escape
Shade and benches make longer walks realistic Check the full climate tables below for monthly averages and packing cues.
Add to your planCovered market · Free
Indoor food hall backup
Ideal when wet days interrupt outdoor plans Check the full climate tables below for monthly averages and packing cues.
Add to your plan
Top places to stay in September
Base near the sights that matter in September
Best overall
Central core
Walkable to main sights with easier 12.5-hour daylight logistics Check the full climate tables below for monthly averages and packing cues.
Best value
One transit stop out
Lower rates than the core while staying close for medium evenings.
Local feel
Neighbourhood streets
Quieter nights and easier restaurant bookings than the busiest tourist blocks.
Top restaurants to visit in September
Breezy rooms and light seasonal plates
Downtown · Classic
Jeju lunch counter
Hearty midday stop when outdoor plans run short on daylight.
Add to your planOld town · Cosy
Neighbourhood bistro
Low light and early dinners match short sunset windows Check the full climate tables below for monthly averages and packing cues.
Add to your planMarket · Casual
Covered market stalls
Fast warm food without a reservation on wet afternoons Check the full climate tables below for monthly averages and packing cues.
Add to your planRiverside · Scenic
Waterfront cafe
Daylight seating works best before the evening chill Check the full climate tables below for monthly averages and packing cues.
Add to your planArts district · Modern
Gallery-side kitchen
Pairs well with museum days when weather turns Check the full climate tables below for monthly averages and packing cues.
Add to your planResidential · Local
Corner noodle or soup spot
Simple, hot bowls that suit cold or humid evenings Check the full climate tables below for monthly averages and packing cues.
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Jeju weather by month
How September compares. Every month links to its full weather guide.
| Month | Avg high | Wet days | Crowds | Cost | Overall | Best for |
|---|---|---|---|---|---|---|
| January | 21°C (70°F) | 5 | Medium | Mid | Great | Mild and comfortable |
| February | 22°C (72°F) | 6 | Medium | Mid | Great | Warm, low rainfall |
| March | 25°C (77°F) | 8 | High | High | Great | Pleasant spring weather |
| April | 28°C (82°F) | 9 | High | High | Great | Warm and sunny |
| May | 31°C (88°F) | 12 | High | Peak | Okay | Getting hot and humid |
| June | 33°C (91°F) | 14 | Medium | Mid | Avoid | Monsoon rains begin |
| July | 35°C (95°F) | 12 | High | High | Avoid | Very hot and humid |
| August | 35°C (95°F) | 13 | High | High | Avoid | Typhoon season risk |
| September | 33°C (91°F) | 10 | Medium | Mid | Okay | Warm — this guide |
| October | 29°C (84°F) | 6 | High | High | Great | Best weather window |
| November | 25°C (77°F) | 5 | Medium | Mid | Great | Comfortable temperatures |
| December | 22°C (72°F) | 4 | High | High | Great | Mild, holiday atmosphere |
Temperatures shown as Jeju monthly averages.
September vs August: September averages 30°C versus 32°C in August — a 2°C cooldown. Crowds shift from High to Medium while pricing moves into mid season. Pick September if you want still warm, easing rains Check the full climate tables below for monthly averages and packing cues.
September vs October: October trends to 26°C, 4°C cooler than September. Expect high crowds and high season rates. Pick October if you prefer best weather window Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
Want September sun instead?
Need more sun than Jeju offers in September?
- 23°C
Seoul in September
A change of scene with comparable September weather. Jeju vs Seoul →
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Busan in September
A change of scene with comparable September weather. Jeju vs Busan →
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Jeju in September FAQ
Everything you need to know about Jeju weather in September
Daytime highs average 33°C (91°F) and nights fall near 26°C (79°F). The monthly mean sits around 30°C. Expect a 1° swing from early to late September Check the full climate tables below for monthly averages and packing cues Check the full climate tables below for monthly averages and packing cues.
How we work this out
Temperature and rainfall figures are 30-year meteorological averages. Crowd levels come from national tourism arrival data. Price bands reflect mid-range accommodation and economy flights from major long-haul cities, sampled quarterly.
Last updated September 10, 2026 · Written by the Holicay travel team