> Useful Information > Korea in Brief > Climate
In East Asia, interaction between the rapidly mixing
atmosphere and the slowly changing oceans are largely
responsible for the monsoon, which affects Korea, China
and Japan as elsewhere in the region. In order to better
understand these patterns and to better prepare for their
outcome, joint collaborative projects among these countries
have been launched by their top meteorologists.
Temperature and Precipitation
The climate of Korea is characterized by four distinct
seasons: spring, summer, autumn and winter. The contrast
between winter and summer is striking. Winter is bitterly
cold and is influenced primarily by cold Siberian fronts.
Summer is hot and humid due to the maritime pacific high.
The transitional seasons, spring and autumn are sunny
and generally dry. The temperatures in Seoul, which is
in the latitude of Richmond, Va., are closer to those
in New York which is located 500 kilometers (300 miles)
farther north from the latitude of Seoul. The variation
of annual mean temperature ranges from 10oC to 16oC except
for the mountainous areas. August is the hottest month
with the mean temperature ranging from 19oC to 27oC. January
is the coldest month with the mean temperature ranging
from -8oC to 7oC. Annual precipitation is about 1,300mm
in the central region.
The prevailing winds are southeasterly to southwesterly
in summer, and northwesterly in winter. The winds are
stronger in winter, from December to February, than those
in other seasons. The land-sea breeze becomes dominant
with weakened monsoon winds in the transitional months,
September and October.
The relative humidity is the highest in July with 80 percent
to 90 percent nationwide, and is the lowest in January
and April with 30 percent to 50 percent. It has a moderate
value of about 70 percent in September and October. The
monsoon front approaches the Korean Peninsula from the
south in late June, moving gradually to the north. Significant
rainfall occurs when a stationary front spreads over the
The rainy season over Korea, the so- called jangma, continues
for a month from late June to late July. A short period
of rainfall comes in early September when the monsoon
front retreats back to the north. This rain occurs over
a period of 30-40 days in June through July at all points
of South Korea, and accounts for more than 50 percent
of annual precipitation in most regions.
Annually, about 28 typhoons occur in the western Pacific,
and only two or three among them approach the Korean Peninsula
between July and October.
Spring : Spring begins
during the middle of March in the central part of the
country, and toward the end of April in the northern
region. Spring is rather short in the north. As the
Siberian high pressure front weakens, the temperature
rises gradually. Yellow sand which originates in the
desert or arid areas of Mongolia and China, known as
hwangsa, occasionally blows into Korea during early
spring. The hwangsa often causes low visibility and
Summer : The summer can be divided into two periods;
jangma, a rainy period which occurs during the early
summer months, and a hot and humid period which occurs
Rainfall during the summer time is characterized by
heavy showers. Daily precipitation often exceeds 100mm
(4 inches), with extremes topping 300mm (12 inches).
Occasional storms caused by typhoons that pass through
the peninsula sometimes cause a great deal of damage,
although the loss of life is rare.
Regional temperature contrasts are not very striking
during the summer season although the northern interior
and the littoral are cooler than the southern region.
In August, the temperature rises abruptly as the jangma
front moves north toward Manchuria. During this period,
the weather becomes extremely hot and humid, particularly
in the western plains and the Nakdonggang river basin
area. The daily high temperature often rises to over
37oC (100oF). Nights are also hot and humid.
of rape growing on Jejudo island; a ravine in summer;
fall foliage on Mt.
Seoraksan; snow on Mt. Deogyusan
Autumn : Autumn is known for crisp weather, much
sunlight and the changing colors of tree leaves. Beginning
in October, the continental air mass brings dry, clear
weather. Traditionally, Koreans enjoy the season of harvest
with festivities of chuseok which is one of the most important
national holidays in Korea. It is often referred to as
the Korean version of the American Thanksgiving.
Winter : The arctic air from the interior of the
Asian continent brings bitter cold and dry weather and
occasional snowfall, while also adding warmth to the cold
and dry winter weather periodically. Significant regional
climate variations are caused by differences in elevation
and proximity to the seas as well as by differences in
latitudinal location. The monthly mean temperature during
the month of January differs by about 20 degrees centigrade
between the northern and the southern peninsula. Snow
remains longer on the ground in the north. The frost-free
period varies from about 130 days in the northern interior
to about 180 days in the central region. On the southern
coast, it lasts roughly 225 days of the year.
Korea has four distinct seasons. Spring and autumn are
rather short, summer is hot and humid, and winter is cold
and dry with abundant snowfall.
Temperatures differ widely from region to region within
Korea, with the average being between 6oC (43oF) and 16oC
(61oF). The average temperature in August, the hottest
period of the year, ranges from 19oC (66oF) to 27oC (81oF),
while in January, the coldest month, temperatures range
from -8oC (17oF) to 7oC (43oF).
In early spring the Korean Peninsula experiences "yellow
sand / dust" carried by wind from the deserts in
northern China. But in mid-April, the country enjoys balmy
weather with the mountains and fields garbed in brilliant
wild flowers. Farmers prepare seedbeds for the annual
rice crop at this time.