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Gunpo weather by month: averages, rainfall & climate trends

Gunpo swings through a wide annual range, with 28.1°C between the monthly means of its warmest and coldest months. Rainfall is strongly seasonal: the bulk of the year's rain falls between June and September. Gunpo weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+1.7°Chigh above average

21° / 11°Today
19° / 9°Average
see today in detail →

How it's changed

+2.3°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4995frost days a year now (2016–2025) · 116 in the 1940sfrost days a year · 116 in the 1940s42days above 30°C a year now (2016–2025) · 16 in the 1940sdays above 30°C · 16 in the 1940s+2.3°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 27 mmhigh 2°low −7°February, rain 28 mmhigh 4°low −4°March, rain 46 mmhigh 10°low 1°April, rain 79 mmhigh 17°low 7°May, rain 87 mmhigh 22°low 12°June, rain 133 mmhigh 26°low 18°July, rain 286 mmhigh 28°low 22°August, rain 215 mmhigh 29°low 23°September, rain 140 mmhigh 25°low 17°October, rain 51 mmhigh 19°low 10°November, rain 49 mmhigh 12°low 3°December, rain 30 mmhigh 4°low −4°wettest month July, 286 mm · 1,171 mm a yearsee month by month →

Right now

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

Right now

18.8°

19°feels like
66%humidity
12°dew point
4 km/hfrom SW
UV index0.1
sunrise06:44sunset17:49day length11h 05m
TodayOvercast21°11°
WedClear16°6°
ThuClear14°3°
FriPartly cloudy20°5°
SatOvercast19°13°
SunLight rain19°14°
MonOvercast20°15°

On this date: October 20

Today (forecast)
21° / 11°
Average for October 20
19° / 9°

High above average · +1.7°C

  • Highest since 1940: 26.0° · 1997
  • Lowest since 1940: 2.5° · 2007
  • One year ago: 17° / 7°

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 Gunpo is sampled from the ECMWF ERA5 reanalysis at 37.37°N, 126.95°E, with daily records since 1940.

Coordinates
37.37°N, 126.95°E
Time zone
Asia/Seoul
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

25 of the last 31 days were warmer than the historical average for that date. Average difference: +2.1°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 29.3°C and nights around 22.6°C. On about 80 nights a year, the temperature never drops below 20°C. In January, the coolest month, afternoons reach about 1.6°C and nights dip to −6.8°C. Frost shows up on around 95 mornings a year.

In total, Gunpo averages about 1,171 mm of precipitation a year; July is usually the wettest month (286 mm) and January the driest (27 mm).

The record here starts in 1940, and since then the annual mean in Gunpo has climbed 2.3°C from the first ten years to the last ten. Days above 30°C have grown noticeably more frequent, from around 15 a year in the first decade to about 40 in the last.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 28°C. Wettest month: July (~286 mm). Whole year averages ~1,171 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.

Gunpo 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
January1.6°−6.8°27 mm39.7 h15.1° (2002)−22.1° (1941)
February4.2°−4.2°28 mm310.6 h18.6° (2021)−20.2° (1969)
March9.9°0.8°46 mm511.7 h25.4° (2025)−14.3° (1969)
April16.9°6.8°79 mm613.0 h29.2° (2005)−2.8° (1941)
May22.3°12.4°87 mm614.0 h31.5° (2019)4.4° (1978)
June26.0°17.7°133 mm714.6 h35.3° (2024)9.4° (1981)
July28.4°22.3°286 mm1414.3 h36.7° (2025)13.6° (1941)
August29.3°22.6°215 mm1213.4 h38.1° (2018)13.8° (1972)
September25.3°17.0°140 mm712.2 h33.7° (2024)6.0° (1956)
October19.4°9.5°51 mm411.0 h29.1° (2006)−3.0° (1986)
November11.7°2.7°49 mm610.0 h25.7° (2023)−10.4° (1996)
December4.2°−3.9°30 mm49.4 h17.8° (2023)−18.9° (2000)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +2.3°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: +0.23°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: +0.28°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: 16.3 early in the record → 42.4 recently. Frost days: 116 → 95.

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 1941: 38.1°C / −22.1°C.

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

Annual rainfall

~1,171 mm/year on average. Last decade: −1% vs that average. Long-term trend: +15 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 Gunpo

Which is the warmest month in Gunpo?
On long-term average, the warmest month in Gunpo is August (mean daily temperature of about 25.7°C) and the coolest is January (about −2.5°C).
How does today's temperature in Gunpo compare to the historical average?
On October 20, 2026, Gunpo is forecast to reach a high of 20.7°C and a low of 10.9°C. The long-term average for this date (the full record since 1940) is a high of 19.0°C and a low of 8.7°C, so today's high is 1.7°C warmer than that average.
How much has Gunpo warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Gunpo is about 2.3°C warmer.
How much does it rain in Gunpo?
Gunpo receives about 1,171 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Gunpo?
Over the full record (since 1940), the annual mean temperature in Gunpo is about 12.2°C. The warmest month is August and the coolest is January.
What are the average temperatures in Gunpo by month?
Average daily highs and lows for each month in Gunpo (°C, full record since 1940): January 2°/−7°, February 4°/−4°, March 10°/1°, April 17°/7°, May 22°/12°, June 26°/18°, July 28°/22°, August 29°/23°, September 25°/17°, October 19°/10°, November 12°/3°, December 4°/−4°.
What is the weather like in Gunpo in summer?
Summer in Gunpo (June to August) is wet and warm. Expect 26–29°C by day and 18–23°C at night, with August the warmest month. Rain picks up through the season: 7 rainy days and 133 mm in June, 12 days and 215 mm in August. It is the wettest season of the year.
What is the weather like in Gunpo in winter?
Winter in Gunpo (December to February) is cold. Daytime highs sit at 2–4°C and nights at −7 to −4°C; January is the coldest month. Rain and snow are steady at around 29 mm a month, spread over roughly 4 days. It is the driest season of the year.
What is the weather like in Gunpo in spring?
March to May is spring in Gunpo, and it is fairly mild. March is still 10°C in the afternoon and 1°C at night, May already 22°C and 12°C. Rain picks up through the season: 5 rainy days and 46 mm in March, 6 days and 87 mm in May.
What is the weather like in Gunpo in autumn?
September to November is autumn in Gunpo, and it is mild. September still brings 25°C afternoons and 17°C nights, November only 12°C and 3°C. Rain eases through the season: 7 rainy days and 140 mm in September, 6 days and 49 mm in November.
How many days a year does it rain in Gunpo?
On long-term average, Gunpo has about 78 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,171 mm.

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