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Gwangmyeong weather by month: averages, rainfall & climate trends

Gwangmyeong swings through a wide annual range, with 28.3°C between the monthly means of its warmest and coldest months. Most of the year's rain is packed into the months from June to September. Gwangmyeong weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+2.7°Chigh above average

21° / 11°Today
18° / 10°Average
see today in detail →

How it's changed

+2.2°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4990frost days a year now (2016–2025) · 109 in the 1940sfrost days a year · 109 in the 1940s27days above 30°C a year now (2016–2025) · 6 in the 1940sdays above 30°C · 6 in the 1940s+2.2°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 24 mmhigh 1°low −7°February, rain 26 mmhigh 3°low −4°March, rain 43 mmhigh 9°low 1°April, rain 77 mmhigh 15°low 7°May, rain 92 mmhigh 20°low 13°June, rain 135 mmhigh 24°low 18°July, rain 302 mmhigh 27°low 22°August, rain 231 mmhigh 28°low 23°September, rain 139 mmhigh 25°low 18°October, rain 52 mmhigh 19°low 11°November, rain 50 mmhigh 11°low 3°December, rain 29 mmhigh 4°low −4°wettest month July, 302 mm · 1,199 mm a yearsee month by month →

Right now

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

Right now

19.6°

19°feels like
56%humidity
11°dew point
5 km/hfrom SW
UV index0.1
sunrise06:45sunset17:49day length11h 04m
TodayOvercast21°11°
WedClear16°8°
ThuClear14°5°
FriPartly cloudy19°6°
SatOvercast19°12°
SunLight rain19°14°
MonOvercast21°15°

On this date: October 20

Today (forecast)
21° / 11°
Average for October 20
18° / 10°

High above average · +2.7°C

  • Highest since 1940: 24.7° · 2016
  • Lowest since 1940: 2.3° · 1956
  • One year ago: 15° / 6°

Every October 20 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 20 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 Gwangmyeong is sampled from the ECMWF ERA5 reanalysis at 37.48°N, 126.87°E, with daily records since 1940.

Coordinates
37.48°N, 126.87°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

The year peaks in August, at around 28.5°C by mid-afternoon, with nights around 23.1°C. On about 85 nights a year, the temperature never drops below 20°C. In January, the coolest month, afternoons reach about 1.0°C and nights dip to −6.9°C. Frost shows up on around 90 mornings a year.

In total, Gwangmyeong averages about 1,199 mm of precipitation a year; July is usually the wettest month (302 mm) and January the driest (24 mm).

Comparing the record's first decade with its most recent one, Gwangmyeong now averages 2.2°C warmer than it did in the 1940s. The count of days past 30°C has risen from roughly 6 a year to 25 between the record's first and last decades.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 28°C. Wettest month: July (~302 mm). Whole year averages ~1,199 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 78 rainy days a year: most in July (~14), fewest in January (~3).

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.

Gwangmyeong 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
January1.0°−6.9°24 mm39.7 h13.1° (1979)−20.4° (2001)
February3.4°−4.5°26 mm310.6 h16.8° (1979)−19.3° (1969)
March8.8°0.9°43 mm411.7 h21.7° (2025)−12.0° (1951)
April15.3°7.3°77 mm613.0 h27.2° (2012)−2.1° (1962)
May20.5°12.9°92 mm614.0 h29.4° (1991)5.8° (1961)
June24.3°18.1°135 mm714.6 h32.6° (1958)10.6° (1974)
July27.1°22.5°302 mm1414.3 h34.8° (2018)14.8° (1954)
August28.5°23.1°231 mm1213.4 h36.0° (2018)14.8° (1972)
September24.8°17.7°139 mm712.2 h33.2° (2024)8.4° (1977)
October18.9°10.5°52 mm511.0 h28.2° (2006)−0.6° (2016)
November11.3°3.4°50 mm69.9 h23.9° (2023)−10.0° (1996)
December3.8°−3.7°29 mm49.4 h15.9° (2023)−17.6° (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 +2.2°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: +0.22°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: +0.27°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: 5.5 early in the record → 27.4 recently. Frost days: 109 → 90.

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 2018, coldest in 2001: 36.0°C / −20.4°C.

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

Annual rainfall

~1,199 mm/year on average. Last decade: −4% vs that average. Long-term trend: +12 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 Gwangmyeong

Which is the warmest month in Gwangmyeong?
On long-term average, the warmest month in Gwangmyeong is August (mean daily temperature of about 25.5°C) and the coolest is January (about −2.8°C).
How does today's temperature in Gwangmyeong compare to the historical average?
On October 20, 2026, Gwangmyeong is forecast to reach a high of 21.2°C and a low of 11.4°C. The long-term average for this date (the full record since 1940) is a high of 18.5°C and a low of 9.7°C, so today's high is 2.7°C warmer than that average.
How much has Gwangmyeong warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Gwangmyeong is about 2.2°C warmer.
How much does it rain in Gwangmyeong?
Gwangmyeong receives about 1,199 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Gwangmyeong?
Over the full record (since 1940), the annual mean temperature in Gwangmyeong is about 12.0°C. The warmest month is August and the coolest is January.
What are the average temperatures in Gwangmyeong by month?
Average daily highs and lows for each month in Gwangmyeong (°C, full record since 1940): January 1°/−7°, February 3°/−4°, March 9°/1°, April 15°/7°, May 20°/13°, June 24°/18°, July 27°/22°, August 28°/23°, September 25°/18°, October 19°/11°, November 11°/3°, December 4°/−4°.
What is the weather like in Gwangmyeong in summer?
June to August is summer in Gwangmyeong, and it is wet and warm. It warms from 24°C by day and 18°C at night in June to 28°C and 23°C in August. Rain rises from 135 mm on 7 days in June to 231 mm on 12 days in August. It is the wettest season of the year.
What is the weather like in Gwangmyeong in winter?
Winter in Gwangmyeong (December to February) is cold. Daytime highs sit at 1–4°C and nights at −7 to −4°C; January is the coldest month. Rain and snow fall on about 3 days a month, adding up to around 26 mm. No season is drier.
What is the weather like in Gwangmyeong in spring?
In spring, March through May, Gwangmyeong is cool. It warms from 9°C by day and 1°C at night in March to 20°C and 13°C in May. Rain rises from 43 mm on 4 days in March to 92 mm on 6 days in May.
What is the weather like in Gwangmyeong in autumn?
September to November is autumn in Gwangmyeong, and it is mild. September still brings 25°C afternoons and 18°C nights, November only 11°C and 3°C. Rain falls off from 139 mm on 7 days in September to 50 mm on 6 days in November.
How many days a year does it rain in Gwangmyeong?
On long-term average, Gwangmyeong has about 78 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,199 mm.

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