WeatherJourney.com

Gyeongsan-si weather by month: averages, rainfall & climate trends

Gyeongsan-si swings through a wide annual range, with 26.4°C between the monthly means of its warmest and coldest months. The heavier rain months run from May to September. Gyeongsan-si weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−4.0°Chigh well below average

16° / 7°Today
20° / 9°Average
see today in detail →

How it's changed

+2.8°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4971frost days a year now (2016–2025) · 103 in the 1940sfrost days a year · 103 in the 1940s67days above 30°C a year now (2016–2025) · 32 in the 1940sdays above 30°C · 32 in the 1940s+2.8°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 25 mmhigh 5°low −4°February, rain 33 mmhigh 8°low −2°March, rain 59 mmhigh 13°low 2°April, rain 84 mmhigh 20°low 8°May, rain 90 mmhigh 25°low 13°June, rain 141 mmhigh 28°low 18°July, rain 207 mmhigh 30°low 23°August, rain 161 mmhigh 31°low 23°September, rain 140 mmhigh 26°low 17°October, rain 53 mmhigh 21°low 10°November, rain 40 mmhigh 14°low 4°December, rain 22 mmhigh 7°low −2°wettest month July, 207 mm · 1,055 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Clear

Right now

8.1°

5°feels like
55%humidity
0°dew point
6 km/hfrom NW
UV index0.0
sunrise06:37sunset17:41day length11h 04m
ThuClear16°7°
FriOvercast21°11°
SatLight rain18°15°
SunOvercast21°16°
MonLight rain19°17°
TueClear18°7°
WedClear13°4°

On this date: October 21

Today (forecast)
16° / 7°
Average for October 21
20° / 9°

High well below average · −4.0°C

  • Highest since 1940: 31.0° · 1997
  • Lowest since 1940: 0.6° · 1955
  • One year ago: 18° / 12°

Every October 21 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 21 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Gyeongsan-si is sampled from the ECMWF ERA5 reanalysis at 35.82°N, 128.74°E, with daily records since 1940.

Coordinates
35.82°N, 128.74°E
Time zone
Asia/Seoul
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

26 of the last 31 days were warmer than the historical average for that date. Average difference: +2.3°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

August brings the year's peak warmth, with afternoons typically reaching 30.9°C and nights around 22.9°C. Around 85 nights a year stay above 20°C. At the other extreme, January brings afternoon highs of about 5.2°C and typical overnight lows of −3.9°C. Around 70 days a year dip below freezing.

Gyeongsan-si picks up roughly 1,055 mm a year, with a peak of 207 mm in July and as little as 22 mm in December.

Over the full record (since 1940), the annual mean temperature in Gyeongsan-si has risen by 2.8°C between its first decade and its last. Days above 30°C have grown noticeably more frequent, from around 30 a year in the first decade to about 65 in the last.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 26°C. Wettest month: July (~207 mm). Whole year averages ~1,055 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 75 rainy days a year: most in July (~13), fewest in December (~2).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Gyeongsan-si month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January5.2°−3.9°25 mm39.8 h17.1° (2002)−17.6° (1981)
February7.7°−2.0°33 mm310.7 h25.5° (2021)−19.4° (1969)
March13.1°2.3°59 mm511.7 h28.1° (2025)−9.6° (1951)
April19.6°8.1°84 mm612.9 h33.2° (2005)−2.5° (1957)
May24.7°13.3°90 mm713.9 h37.4° (2014)4.2° (1947)
June27.8°18.1°141 mm814.4 h38.4° (2005)8.9° (1945)
July29.9°22.7°207 mm1314.2 h40.0° (1994)13.2° (1945)
August30.9°22.9°161 mm1113.4 h40.2° (1967)13.3° (1956)
September26.3°17.3°140 mm812.2 h36.8° (1994)5.5° (1956)
October21.1°10.1°53 mm411.1 h31.0° (1997)−1.3° (1976)
November14.3°3.7°40 mm410.1 h27.6° (2023)−7.4° (1956)
December7.5°−1.9°22 mm29.6 h20.5° (1953)−13.9° (1973)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +2.8°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.34°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Mar–May is warming fastest: +0.41°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 32.2 early in the record → 66.5 recently. Frost days: 103 → 71.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 1967, coldest in 1969: 40.2°C / −19.4°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~1,055 mm/year on average. Last decade: +8% vs that average. Long-term trend: +20 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Gyeongsan-si

Which is the warmest month in Gyeongsan-si?
On long-term average, the warmest month in Gyeongsan-si is August (mean daily temperature of about 26.6°C) and the coolest is January (about 0.2°C).
How does today's temperature in Gyeongsan-si compare to the historical average?
On October 21, 2026, Gyeongsan-si is forecast to reach a high of 16.3°C and a low of 6.8°C. The long-term average for this date (the full record since 1940) is a high of 20.3°C and a low of 9.3°C, so today's high is 4.0°C cooler than that average.
How much has Gyeongsan-si warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Gyeongsan-si is about 2.8°C warmer.
How much does it rain in Gyeongsan-si?
Gyeongsan-si receives about 1,055 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Gyeongsan-si?
Over the full record (since 1940), the annual mean temperature in Gyeongsan-si is about 13.8°C. The warmest month is August and the coolest is January.
What are the average temperatures in Gyeongsan-si by month?
Average daily highs and lows for each month in Gyeongsan-si (°C, full record since 1940): January 5°/−4°, February 8°/−2°, March 13°/2°, April 20°/8°, May 25°/13°, June 28°/18°, July 30°/23°, August 31°/23°, September 26°/17°, October 21°/10°, November 14°/4°, December 7°/−2°.
What is the weather like in Gyeongsan-si in summer?
Summer in Gyeongsan-si (June to August) is wet and warm. Expect 28–31°C by day and 18–23°C at night, with August the warmest month. Rain is steady at around 170 mm a month, spread over roughly 11 days. No season is wetter.
What is the weather like in Gyeongsan-si in winter?
Winter in Gyeongsan-si (December to February) is cold. Daytime highs sit at 5–8°C and nights at −4 to −2°C; January is the coldest month. Rain falls on about 3 days a month, adding up to around 27 mm. It is the driest season of the year.
What is the weather like in Gyeongsan-si in spring?
In spring, March through May, Gyeongsan-si is mild. March is still 13°C in the afternoon and 2°C at night, May already 25°C and 13°C. Rain rises from 59 mm on 5 days in March to 90 mm on 7 days in May.
What is the weather like in Gyeongsan-si in autumn?
Autumn in Gyeongsan-si (September to November) is mild. September still brings 26°C afternoons and 17°C nights, November only 14°C and 4°C. Rain falls off from 140 mm on 8 days in September to 40 mm on 4 days in November.
How many days a year does it rain in Gyeongsan-si?
On long-term average, Gyeongsan-si has about 75 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,055 mm.

Weather in nearby cities