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Heshan weather by month: averages, rainfall & climate trends

Heshan swings through a wide annual range, with 24.1°C between the monthly means of its warmest and coldest months. The heavier rain months run from March to August. Heshan weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−1.8°Chigh below average

21° / 16°Today
22° / 15°Average
see today in detail →

How it's changed

+0.7°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4910frost days a year now (2016–2025) · 19 in the 1940sfrost days a year · 19 in the 1940s98days above 30°C a year now (2016–2025) · 88 in the 1940sdays above 30°C · 88 in the 1940s+0.7°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 76 mmhigh 8°low 2°February, rain 103 mmhigh 10°low 4°March, rain 168 mmhigh 15°low 8°April, rain 221 mmhigh 21°low 14°May, rain 264 mmhigh 26°low 19°June, rain 301 mmhigh 29°low 23°July, rain 187 mmhigh 33°low 26°August, rain 156 mmhigh 32°low 25°September, rain 97 mmhigh 28°low 21°October, rain 98 mmhigh 23°low 15°November, rain 81 mmhigh 17°low 10°December, rain 57 mmhigh 11°low 4°wettest month June, 301 mm · 1,810 mm a yearsee month by month →

Right now

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

Right now

17.6°

18°feels like
87%humidity
15°dew point
8 km/hfrom N
UV index0.0
sunrise06:33sunset17:57day length11h 24m
TodayOvercast21°16°
TueOvercast19°16°
WedLight rain16°14°
ThuOvercast16°13°
FriPartly cloudy18°13°
SatPartly cloudy21°14°
SunOvercast20°16°

On this date: October 19

Today (forecast)
21° / 16°
Average for October 19
22° / 15°

High below average · −1.8°C

  • Highest since 1940: 31.3° · 2014
  • Lowest since 1940: 8.3° · 1963
  • One year ago: 15° / 12°

Every October 19 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 19 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 Heshan is sampled from the ECMWF ERA5 reanalysis at 28.57°N, 112.35°E, with daily records since 1940.

Coordinates
28.57°N, 112.35°E
Time zone
Asia/Shanghai
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

22 of the last 31 days were warmer than the historical average for that date. Average difference: +1.0°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

July brings the year's peak warmth, with afternoons typically reaching 33.0°C and nights around 26.2°C. Roughly 100 days a year now top 30°C. At the other extreme, January brings afternoon highs of about 8.3°C and typical overnight lows of 1.9°C.

Heshan picks up roughly 1,810 mm a year, with a peak of 301 mm in June and as little as 57 mm in December. A typical year brings rain or snow on around 142 days.

Comparing the record's first decade with its most recent one, Heshan now averages 0.7°C warmer than it did in the 1940s. Recent years have brought less rain as well. The last decade sits roughly 12% under the long-term average.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 24°C. Wettest month: June (~301 mm). Whole year averages ~1,810 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 142 rainy days a year: most in April (~16), fewest in December (~7).

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.

Heshan 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
January8.3°1.9°76 mm910.4 h25.1° (1949)−17.9° (1955)
February10.1°3.7°103 mm1211.0 h29.4° (2010)−11.6° (1957)
March15.2°8.5°168 mm1511.8 h33.5° (2025)−5.0° (1954)
April21.4°14.4°221 mm1612.7 h35.6° (2005)2.4° (1972)
May25.9°19.1°264 mm1613.4 h36.3° (2011)9.2° (1960)
June29.4°23.1°301 mm1513.8 h38.8° (1946)14.6° (1987)
July33.0°26.2°187 mm1313.7 h42.1° (1961)19.2° (2011)
August32.5°25.5°156 mm1313.0 h42.2° (1953)17.0° (2005)
September28.2°21.2°97 mm912.2 h40.8° (1946)12.3° (1967)
October22.6°15.4°98 mm911.3 h39.3° (2022)4.0° (1978)
November16.8°9.6°81 mm810.5 h32.4° (2022)−3.4° (1979)
December11.0°4.0°57 mm710.2 h24.7° (1989)−10.2° (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 +0.7°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: +0.12°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: +0.20°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: 88.0 early in the record → 98.2 recently. Frost days: 19 → 10.

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 1953, coldest in 1955: 42.2°C / −17.9°C.

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

Annual rainfall

~1,810 mm/year on average. Last decade: −12% vs that average. Long-term trend: −43 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 Heshan

Which is the warmest month in Heshan?
On long-term average, the warmest month in Heshan is July (mean daily temperature of about 29.4°C) and the coolest is January (about 5.3°C).
How does today's temperature in Heshan compare to the historical average?
On October 19, 2026, Heshan is forecast to reach a high of 20.6°C and a low of 16.3°C. The long-term average for this date (the full record since 1940) is a high of 22.4°C and a low of 15.0°C, so today's high is 1.8°C cooler than that average.
How much has Heshan warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Heshan is about 0.7°C warmer.
How much does it rain in Heshan?
Heshan receives about 1,810 mm of precipitation per year on long-term average, with June typically the wettest month.
What is the average temperature in Heshan?
Over the full record (since 1940), the annual mean temperature in Heshan is about 17.7°C. The warmest month is July and the coolest is January.
What are the average temperatures in Heshan by month?
Average daily highs and lows for each month in Heshan (°C, full record since 1940): January 8°/2°, February 10°/4°, March 15°/8°, April 21°/14°, May 26°/19°, June 29°/23°, July 33°/26°, August 32°/25°, September 28°/21°, October 23°/15°, November 17°/10°, December 11°/4°.
What is the weather like in Heshan in summer?
June to August is summer in Heshan, and it is wet and hot. Expect 29–33°C by day and 23–26°C at night, with July the warmest month. Rain falls off from 301 mm on 15 days in June to 156 mm on 13 days in August.
What is the weather like in Heshan in winter?
Winter in Heshan (December to February) is on the cool side. Daytime highs sit at 8–11°C and nights at 2–4°C; January is the coldest month. Rain rises from 57 mm on 7 days in December to 103 mm on 12 days in February.
What is the weather like in Heshan in spring?
Spring in Heshan (March to May) is wet and mild. March starts at 15°C by day and 8°C at night; by May it is 26°C and 19°C. Rain picks up through the season: 15 rainy days and 168 mm in March, 16 days and 264 mm in May.
What is the weather like in Heshan in autumn?
In autumn, September through November, Heshan is pleasantly warm. September is still 28°C by day and 21°C at night; by November it is down to 17°C and 10°C. Rain is steady at around 92 mm a month, spread over roughly 8 days.
How many days a year does it rain in Heshan?
On long-term average, Heshan has about 142 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,810 mm.

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