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Daejeon weather by month: averages, rainfall & climate trends

Daejeon swings through a wide annual range, with 27.5°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. Daejeon weather by month: average temperatures, rainfall, records and how the climate has changed since 1940.

Today vs average

+7.7°Chigh well above average

29° / 19°Today
21° / 11°Average
see today in detail →

How it's changed

+2.3°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4980frost days a year now (2016–2025) · 100 in the 1940sfrost days a year · 100 in the 1940s61days above 30°C a year now (2016–2025) · 32 in the 1940sdays above 30°C · 32 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 31 mmhigh 3°low −5°February, rain 36 mmhigh 6°low −3°March, rain 58 mmhigh 12°low 2°April, rain 83 mmhigh 19°low 8°May, rain 91 mmhigh 24°low 14°June, rain 142 mmhigh 28°low 19°July, rain 244 mmhigh 30°low 23°August, rain 183 mmhigh 31°low 23°September, rain 136 mmhigh 26°low 17°October, rain 54 mmhigh 21°low 10°November, rain 46 mmhigh 13°low 4°December, rain 31 mmhigh 6°low −2°wettest month July, 244 mm · 1,136 mm a yearsee month by month →

Right now

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

Right now

21.0°

24°feels like
90%humidity
19°dew point
4 km/hfrom W
UV index0.0
sunrise06:34sunset17:59day length11h 25m
TodayPartly cloudy29°19°
TuePartly cloudy20°16°
WedClear18°9°
ThuClear21°6°
FriOvercast22°8°
SatOvercast26°14°
SunOvercast24°18°

On this date: October 12

Today (forecast)
29° / 19°
Average for October 12
21° / 11°

High well above average · +7.7°C

  • Record high: 28.0° · 1951
  • Record low: 2.3° · 1971
  • One year ago: 24° / 19°

Every October 12 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 12 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 Daejeon is sampled from the ECMWF ERA5 reanalysis at 36.35°N, 127.38°E, with daily records since 1940.

Coordinates
36.35°N, 127.38°E
Time zone
Asia/Seoul
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

24 of the last 31 days were warmer than the historical average for that date. Average difference: +2.0°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 30.6°C and nights around 23.0°C. Around 85 nights a year stay above 20°C. The coolest month is January, when afternoons reach about 3.3°C and overnight lows sit around −5.3°C. Frost shows up on around 80 mornings a year.

In total, Daejeon averages about 1,136 mm of precipitation a year; July is usually the wettest month (244 mm) and December the driest (31 mm).

Over the full record (since 1940), the annual mean temperature in Daejeon has risen by 2.3°C between its first decade and its last. The count of days past 30°C has risen from roughly 30 a year to 60 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 (~244 mm). Whole year averages ~1,136 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 82 rainy days a year: most in July (~14), fewest in January (~4).

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.

Daejeon 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. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightRecord highRecord low
January3.3°−5.3°31 mm49.8 h17.0° (1979)−21.7° (1967)
February5.9°−3.0°36 mm410.7 h22.4° (2021)−21.4° (1969)
March11.9°2.0°58 mm611.7 h29.8° (2025)−11.2° (2004)
April19.0°8.2°83 mm712.9 h32.3° (2005)−2.0° (1972)
May24.1°13.6°91 mm713.9 h35.4° (1962)4.7° (2019)
June27.6°18.6°142 mm914.5 h36.6° (1958)10.7° (1992)
July29.7°22.9°244 mm1414.2 h38.5° (2018)14.5° (1966)
August30.6°23.0°183 mm1213.4 h39.8° (2018)14.3° (1972)
September26.2°17.4°136 mm812.2 h36.2° (2024)6.2° (1957)
October20.5°10.2°54 mm411.0 h32.0° (2021)−0.8° (1986)
November13.1°3.6°46 mm510.0 h27.0° (2023)−9.3° (1987)
December5.8°−2.5°31 mm49.5 h19.9° (2023)−15.1° (1967)

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: +0.25°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

Dec–Feb is warming fastest: +0.30°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: 31.6 early in the record → 61.2 recently. Frost days: 100 → 80.

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

All-time high in 2018, all-time low in 1967: 39.8°C / −21.7°C.

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

Annual rainfall

~1,136 mm/year on average. Last decade: +2% vs that average. Long-term trend: +16 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 Daejeon

Which is the warmest month in Daejeon?
On long-term average, the warmest month in Daejeon is August (mean daily temperature of about 26.5°C) and the coolest is January (about −1.0°C).
How does today's temperature in Daejeon compare to the historical average?
On October 12, 2026, Daejeon is forecast to reach a high of 28.9°C and a low of 19.3°C. The long-term average for this date (the full record since 1940) is a high of 21.2°C and a low of 11.1°C, so today's high is 7.7°C warmer than that average.
How much has Daejeon warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Daejeon is about 2.3°C warmer.
How much does it rain in Daejeon?
Daejeon receives about 1,136 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Daejeon?
Over the full record (since 1940), the annual mean temperature in Daejeon is about 13.4°C. The warmest month is August and the coolest is January.
What are the average temperatures in Daejeon by month?
Average daily highs and lows for each month in Daejeon (°C, full record since 1940): January 3°/−5°, February 6°/−3°, March 12°/2°, April 19°/8°, May 24°/14°, June 28°/19°, July 30°/23°, August 31°/23°, September 26°/17°, October 21°/10°, November 13°/4°, December 6°/−2°.
What is the weather like in Daejeon in summer?
In summer, June through August, Daejeon is wet and warm. Afternoons run 28–31°C and nights 19–23°C; August is the warmest month. Rain is steady at around 190 mm a month, spread over roughly 12 days. No season is wetter.
What is the weather like in Daejeon in winter?
In winter, December through February, Daejeon is cold. Expect 3–6°C by day and −5 to −2°C at night, with January the coldest month. Rain and snow are steady at around 33 mm a month, spread over roughly 4 days. It is the driest season of the year.
What is the weather like in Daejeon in spring?
March to May is spring in Daejeon, and it is mild. March starts at 12°C by day and 2°C at night; by May it is 24°C and 14°C. Rain picks up through the season: 6 rainy days and 58 mm in March, 7 days and 91 mm in May.
What is the weather like in Daejeon in autumn?
In autumn, September through November, Daejeon is mild. It cools from 26°C by day and 17°C at night in September to 13°C and 4°C in November. Rain falls off from 136 mm on 8 days in September to 46 mm on 5 days in November.
How many days a year does it rain in Daejeon?
On long-term average, Daejeon has about 82 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,136 mm.

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