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Hallasan

Hallasan 1
Travel guide
1
Travel guide

Top 10 things to do in Hallasan

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Best time to visit Hallasan

Data source：Meteostat
Last updated：2025-09

Weather in Hallasan throughout the year

  • Spring (March–May): Average 10.8–18.1°C, mild climate with abundant rainfall, suitable for hiking and trekking. Common activities: flower viewing, hiking, trekking. Recommended clothing: light jacket, long-sleeved clothing, comfortable hiking shoes.
  • Summer (June–August): Average 22.5–28.5°C, hot and humid, with more rainfall, especially frequent in June and July. Common activities: short stays at summer resorts, enjoying mountain views. Recommended clothing: breathable and sweat-wicking clothing, light rain gear.
  • Autumn (September–November): Average 19.2–25.3°C, comfortable and pleasant climate, September has the most rainfall, but overall rainfall decreases. Common activities: hiking, trekking, viewing maple leaves (depending on actual conditions). Recommended clothing: light jacket or long-sleeved clothing.
  • Winter (December–February): Average 6.6–8.2°C, cold and dry, with possible snowfall. Common activities: enjoying winter mountain scenery (pay attention to safety). Recommended clothing: warm clothing, thick jacket, waterproof and windproof jacket, warm hat, gloves, and scarf.

Weather in Hallasan

Annual average temperature: approx. 17°C / Annual rainfall: approx. 1705 mm / Summer humidity: 70%–80% / Rainiest month: September

Hallasan weather by month

Month
Temperature (°C)
Rainfall (mm)
January
6.6°C
99
February
7.3°C
97.5
March
10.8°C
114.9
April
14.9°C
121.6
May
18.1°C
148.8
June
22.5°C
215.7
July
27.6°C
207.3
August
28.5°C
109.5
September
25.3°C
225.8
October
19.2°C
87.8
November
14.4°C
201.5
December
8.2°C
76

7-day weather forecast for Hallasan

11/2
Monday
Sunny
19.2°C/13.4°C
11/3
Tuesday
Overcast
18°C/11.1°C
11/4
Wednesday
Overcast
18.8°C/14°C
11/5
Thursday
Patchy rain nearby
20.4°C/15.9°C
11/6
Friday
Patchy rain nearby
17°C/10.8°C
11/7
Saturday
Sunny
12.7°C/8.3°C
11/8
Sunday
Overcast
12.8°C/9.5°C

Hallasan travel FAQs and useful info

How long does it take to climb Hallasan?

Generally considered a challenging route, climbing Hallasan typically takes an average of 7 hours and 33 minutes to complete. This 11.1-mile point-to-point trail near Seogwipo-si, Jeju Island is very popular for hiking and walking, so expect to encounter other people during your exploration.

Can Hallasan erupt?

Hallasan is classified as an active volcano. While its last confirmed eruption was over 5,000 years ago, geological evidence suggests its last eruption was around at least 2,000 years ago, and historical accounts point to activity in 1007 CE. This means it has erupted within the last 10,000 years, classifying it as active.

Is Hallasan still active?

Hallasan is considered an active volcano because it has erupted within the last 10,000 years. While its last confirmed eruption was over 5,000 years ago, some geological and historical records suggest more recent activity. Therefore, by some classifications, it falls into the active category.

Why is Hallasan mountain famous?

Hallasan Mountain is famous for its unique vertical ecosystem of plants. This diverse flora is a direct result of the varying temperatures found along the mountainside, creating distinct ecological zones as you ascend.

What is the best time of year to hike Hallasan?

The best times to hike Hallasan are generally spring (April to May) for blooming flowers and autumn (September to October) for vibrant fall foliage. Summer can be hot and humid with frequent rain, while winter offers a snowy landscape but requires proper gear and caution due to icy conditions.