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Hyesan weather by month: averages, rainfall & climate trends

Hyesan swings through a wide annual range, with 35.8°C between the monthly means of its warmest and coldest months. Most of the year's rain is packed into the months from May to August. Hyesan weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+0.5°Chigh near average

10° / 3°Today
10° / 0°Average
see today in detail →

How it's changed

+2.6°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49155frost days a year now (2016–2025) · 174 in the 1940sfrost days a year · 174 in the 1940s12days above 30°C a year now (2016–2025) · 1 in the 1940sdays above 30°C · 1 in the 1940s+2.6°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 20 mmhigh −8°low −22°February, rain 24 mmhigh −4°low −18°March, rain 42 mmhigh 3°low −9°April, rain 65 mmhigh 12°low 1°May, rain 94 mmhigh 19°low 7°June, rain 115 mmhigh 23°low 13°July, rain 179 mmhigh 26°low 17°August, rain 157 mmhigh 26°low 17°September, rain 72 mmhigh 21°low 9°October, rain 48 mmhigh 13°low 2°November, rain 44 mmhigh 3°low −8°December, rain 26 mmhigh −6°low −19°wettest month July, 179 mm · 886 mm a yearsee month by month →

Right now

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

Right now

6.0°

2°feels like
46%humidity
−5°dew point
11 km/hfrom NW
UV index0.0
sunrise06:51sunset17:31day length10h 40m
TodayOvercast10°3°
TueClear3°−5°
WedClear6°−7°
ThuOvercast12°−8°
FriMostly clear13°−3°
SatClear1°−6°
SunPartly cloudy2°−7°

On this date: October 26

Today (forecast)
10° / 3°
Average for October 26
10° / 0°

High near average · +0.5°C

  • Highest since 1940: 19.6° · 2024
  • Lowest since 1940: −11.4° · 1958
  • One year ago: 10° / −4°

Every October 26 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 26 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 Hyesan is sampled from the ECMWF ERA5 reanalysis at 41.40°N, 128.18°E, with daily records since 1940.

Coordinates
41.40°N, 128.18°E
Time zone
Asia/Pyongyang
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

17 of the last 31 days were warmer than the historical average for that date. Average difference: +0.7°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 warmest month is July, with typical afternoon highs of 25.9°C and nights around 17.3°C. The coolest month is January, when afternoons reach about −7.9°C and overnight lows sit around −21.7°C. Frost shows up on around 155 mornings a year.

In total, Hyesan averages about 886 mm of precipitation a year; July is usually the wettest month (179 mm) and January the driest (20 mm).

Comparing the record's first decade with its most recent one, Hyesan now averages 2.6°C warmer than it did in the 1940s. That last decade has also been the warmest in the record.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 36°C. Wettest month: July (~179 mm). Whole year averages ~886 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 100 rainy days a year: most in July (~16), 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.

Hyesan 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
January−7.9°−21.7°20 mm39.3 h7.6° (2023)−36.3° (1985)
February−4.3°−17.8°24 mm310.4 h14.4° (2010)−34.5° (1940)
March2.7°−8.6°42 mm611.7 h21.1° (2018)−28.7° (1951)
April11.5°0.7°65 mm913.1 h29.0° (2018)−16.4° (1941)
May18.6°7.3°94 mm1214.3 h32.1° (2017)−5.5° (1979)
June22.7°12.9°115 mm1415.0 h32.7° (1962)2.9° (1940)
July25.9°17.3°179 mm1614.7 h35.0° (2018)7.4° (2015)
August25.8°16.6°157 mm1313.7 h35.5° (2018)3.9° (2009)
September20.6°9.5°72 mm712.3 h29.9° (1999)−2.6° (1981)
October13.1°1.9°48 mm710.9 h27.0° (2019)−15.6° (1955)
November3.0°−8.3°44 mm69.6 h18.7° (2023)−32.2° (1947)
December−5.8°−19.3°26 mm49.0 h9.7° (1989)−36.1° (1947)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +2.6°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: +0.31°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: +0.45°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: 1.2 early in the record → 12.4 recently. Frost days: 174 → 155.

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 1985: 35.5°C / −36.3°C.

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

Annual rainfall

~886 mm/year on average. Last decade: +4% vs that average. Long-term trend: +3 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 Hyesan

Which is the warmest month in Hyesan?
On long-term average, the warmest month in Hyesan is July (mean daily temperature of about 21.4°C) and the coolest is January (about −14.4°C).
How does today's temperature in Hyesan compare to the historical average?
On October 26, 2026, Hyesan is forecast to reach a high of 10.2°C and a low of 2.5°C. The long-term average for this date (the full record since 1940) is a high of 9.7°C and a low of −0.3°C, so today's high is 0.5°C warmer than that average.
How much has Hyesan warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Hyesan is about 2.6°C warmer.
How much does it rain in Hyesan?
Hyesan receives about 886 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Hyesan?
Over the full record (since 1940), the annual mean temperature in Hyesan is about 4.9°C. The warmest month is July and the coolest is January.
What are the average temperatures in Hyesan by month?
Average daily highs and lows for each month in Hyesan (°C, full record since 1940): January −8°/−22°, February −4°/−18°, March 3°/−9°, April 12°/1°, May 19°/7°, June 23°/13°, July 26°/17°, August 26°/17°, September 21°/9°, October 13°/2°, November 3°/−8°, December −6°/−19°.
What is the weather like in Hyesan in summer?
June to August is summer in Hyesan, and it is wet and pleasantly warm. Daytime highs sit at 23–26°C and nights at 13–17°C; July is the warmest month. Rain is steady at around 150 mm a month, spread over roughly 14 days. It is the wettest season of the year.
What is the weather like in Hyesan in winter?
In winter, December through February, Hyesan is freezing. Afternoons run −8 to −4°C and nights −22 to −18°C; January is the coldest month. Snow falls on about 3 days a month, adding up to around 23 mm of precipitation. No season is drier.
What is the weather like in Hyesan in spring?
March to May is spring in Hyesan, and it is on the cool side. March starts at 3°C by day and −9°C at night; by May it is 19°C and 7°C. Rain and snow rise from 42 mm on 6 days in March to 94 mm on 12 days in May.
What is the weather like in Hyesan in autumn?
September to November is autumn in Hyesan, and it is cool. September is still 21°C by day and 9°C at night; by November it is down to 3°C and −8°C. Rain and snow fall off from 72 mm on 7 days in September to 44 mm on 6 days in November.
How many days a year does it rain in Hyesan?
On long-term average, Hyesan has about 100 days a year with at least 2 mm of rain or snow. The annual total is roughly 886 mm.

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