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Hangzhou weather by month: averages, rainfall & climate trends

Hangzhou grew up around West Lake at the Grand Canal's southern end, and its year still moves with the water: June's plum rains, humid monsoon summers and the surge of the Qiantang tidal bore. Hangzhou weather by month: average temperatures, rainfall, records and how the climate has changed since 1940.

Today vs average

+8.3°Chigh well above average

31° / 22°Today
23° / 15°Average
see today in detail →

How it's changed

+1.7°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4914frost days a year now (2016–2025) · 33 in the 1940sfrost days a year · 33 in the 1940s100days above 30°C a year now (2016–2025) · 78 in the 1940sdays above 30°C · 78 in the 1940s+1.7°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 66 mmhigh 8°low 1°February, rain 81 mmhigh 10°low 3°March, rain 119 mmhigh 15°low 7°April, rain 142 mmhigh 21°low 13°May, rain 196 mmhigh 26°low 18°June, rain 314 mmhigh 29°low 22°July, rain 162 mmhigh 34°low 26°August, rain 132 mmhigh 33°low 26°September, rain 131 mmhigh 28°low 22°October, rain 72 mmhigh 23°low 15°November, rain 60 mmhigh 17°low 9°December, rain 49 mmhigh 11°low 3°wettest month June, 314 mm · 1,524 mm a yearsee month by month →

Right now

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

Right now

29.7°

33°feels like
60%humidity
21°dew point
5 km/hfrom SW
UV index3.1
sunrise06:03sunset17:25day length11h 23m
TodayPartly cloudy31°22°
MonOvercast25°20°
TueClear33°20°
WedPartly cloudy21°16°
ThuPartly cloudy20°14°
FriPartly cloudy23°15°
SatLight rain21°18°

On this date: October 18

Today (forecast)
31° / 22°
Average for October 18
23° / 15°

High well above average · +8.3°C

  • Record high: 31.9° · 2024
  • Record low: 7.5° · 1963
  • One year ago: 23° / 19°

Every October 18 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 18 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 Hangzhou is sampled from the ECMWF ERA5 reanalysis at 30.29°N, 120.16°E, with daily records since 1940.

Coordinates
30.29°N, 120.16°E
Time zone
Asia/Shanghai
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: +2.4°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

Hangzhou sits in northwestern Zhejiang province, in the Yangtze River Delta at the southern terminus of the Grand Canal, its centre wrapped around West Lake, with the Qiantang River passing just to the south. The climate is humid subtropical (Köppen Cfa), swinging through four well-marked seasons: summers are drawn-out, sweltering and sticky, while winters turn chilly and grey with less rain and the occasional snowfall. The Asian monsoon sets the rhythm, delivering the plum rains in June.

Late summer carries typhoon risk: storms in August and September usually make landfall on Zhejiang's southern coast rather than striking the city head-on, while the Qiantang River's towering tidal bore remains a spectacle in its own right. Heat is the sharper modern concern: August 2024 brought exceptionally intense heat, and China's summer-2022 heatwave dragged on for more than nine weeks. The country has warmed faster than the global average since the 1950s.

The year peaks in July, at around 33.5°C by mid-afternoon, with nights around 26.2°C. In a typical recent year, around 100 days reach 30°C or more. At the other extreme, January brings afternoon highs of about 8.5°C and typical overnight lows of 1.1°C.

Hangzhou picks up roughly 1,524 mm a year, with a peak of 314 mm in June and as little as 49 mm in December.

Over the full record (since 1940), the annual mean temperature in Hangzhou has risen by 1.7°C between its first decade and its last. Where the first decade averaged 35 frost days a year, the recent one saw about 14.

Sources:en.wikipedia.orgen.wikipedia.orgcma.gov.cn

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 25°C. Wettest month: June (~314 mm). Whole year averages ~1,524 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 119 rainy days a year: most in June (~14), fewest in December (~6).

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.

Hangzhou 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
January8.5°1.1°66 mm810.2 h25.4° (1949)−14.5° (1940)
February10.1°2.8°81 mm910.9 h30.0° (2009)−15.7° (1969)
March14.8°7.2°119 mm1211.8 h35.4° (2025)−3.7° (1956)
April20.9°12.9°142 mm1212.7 h34.8° (2023)2.2° (1957)
May25.5°17.9°196 mm1313.5 h39.6° (2011)7.9° (1965)
June28.7°22.2°314 mm1413.9 h40.4° (2009)13.4° (1987)
July33.5°26.2°162 mm1113.8 h43.0° (2009)18.2° (2015)
August33.1°25.7°132 mm1213.1 h43.9° (2024)18.2° (1998)
September28.3°21.5°131 mm1012.2 h41.5° (1946)11.6° (2012)
October23.0°15.4°72 mm611.2 h38.9° (2022)2.8° (1978)
November17.3°9.5°60 mm610.4 h32.2° (2023)−4.5° (1979)
December11.1°3.2°49 mm610.1 h25.2° (1968)−14.1° (1985)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.7°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: +0.22°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: +0.30°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: 78.1 early in the record → 100.0 recently. Frost days: 33 → 14.

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 2024, all-time low in 1969: 43.9°C / −15.7°C.

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

Annual rainfall

~1,524 mm/year on average. Last decade: −1% vs that average. Long-term trend: +2 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 Hangzhou

Which is the warmest month in Hangzhou?
On long-term average, the warmest month in Hangzhou is July (mean daily temperature of about 29.5°C) and the coolest is January (about 4.7°C).
How does today's temperature in Hangzhou compare to the historical average?
On October 18, 2026, Hangzhou is forecast to reach a high of 30.9°C and a low of 21.6°C. The long-term average for this date (the full record since 1940) is a high of 22.6°C and a low of 14.7°C, so today's high is 8.3°C warmer than that average.
How much has Hangzhou warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Hangzhou is about 1.7°C warmer.
How much does it rain in Hangzhou?
Hangzhou receives about 1,524 mm of precipitation per year on long-term average, with June typically the wettest month.
What is the average temperature in Hangzhou?
Over the full record (since 1940), the annual mean temperature in Hangzhou is about 17.3°C. The warmest month is July and the coolest is January.
What are the average temperatures in Hangzhou by month?
Average daily highs and lows for each month in Hangzhou (°C, full record since 1940): January 8°/1°, February 10°/3°, March 15°/7°, April 21°/13°, May 26°/18°, June 29°/22°, July 34°/26°, August 33°/26°, September 28°/22°, October 23°/15°, November 17°/9°, December 11°/3°.
What is the weather like in Hangzhou in summer?
Summer in Hangzhou (June to August) is wet and hot. It warms from 29°C by day and 22°C at night in June to 33°C and 26°C in August. Rain eases through the season: 14 rainy days and 314 mm in June, 12 days and 132 mm in August. No season is wetter.
What is the weather like in Hangzhou in winter?
In winter, December through February, Hangzhou is on the cool side. Daytime highs sit at 8–11°C and nights at 1–3°C; January is the coldest month. Rain picks up through the season: 6 rainy days and 49 mm in December, 9 days and 81 mm in February. It is the driest season of the year.
What is the weather like in Hangzhou in spring?
March to May is spring in Hangzhou, and it is wet and mild. March is still 15°C in the afternoon and 7°C at night, May already 26°C and 18°C. Rain rises from 119 mm on 12 days in March to 196 mm on 13 days in May.
What is the weather like in Hangzhou in autumn?
September to November is autumn in Hangzhou, and it is pleasantly warm. September is still 28°C by day and 22°C at night; by November it is down to 17°C and 9°C. Rain falls off from 131 mm on 10 days in September to 60 mm on 6 days in November.
How many days a year does it rain in Hangzhou?
On long-term average, Hangzhou has about 119 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,524 mm.

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