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Bishan weather by month: averages, rainfall & climate trends

Seasons run to extremes in Bishan: monthly means span 20.4°C between the coldest month and the warmest. Rainfall leans toward the stretch from April to September. Bishan weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−0.3°Chigh near average

21° / 17°Today
21° / 16°Average
see today in detail →

How it's changed

+1.1°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–491frost days a year now (2016–2025) · 3 in the 1940sfrost days a year · 3 in the 1940s93days above 30°C a year now (2016–2025) · 75 in the 1940sdays above 30°C · 75 in the 1940s+1.1°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 36 mmhigh 11°low 6°February, rain 36 mmhigh 13°low 7°March, rain 69 mmhigh 18°low 11°April, rain 112 mmhigh 23°low 16°May, rain 152 mmhigh 26°low 19°June, rain 161 mmhigh 29°low 22°July, rain 180 mmhigh 32°low 25°August, rain 161 mmhigh 33°low 25°September, rain 126 mmhigh 28°low 21°October, rain 101 mmhigh 22°low 17°November, rain 68 mmhigh 17°low 12°December, rain 43 mmhigh 12°low 7°wettest month July, 180 mm · 1,245 mm a yearsee month by month →

Right now

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

Right now

17.8°

18°feels like
70%humidity
12°dew point
5 km/hfrom E
UV index0.0
sunrise07:01sunset18:17day length11h 17m
ThuOvercast21°17°
FriOvercast21°17°
SatOvercast21°16°
SunOvercast21°18°
MonOvercast20°17°
TueOvercast17°16°
WedOvercast17°15°

On this date: October 21

Today (forecast)
21° / 17°
Average for October 21
21° / 16°

High near average · −0.3°C

  • Highest since 1940: 30.1° · 2015
  • Lowest since 1940: 7.6° · 1972
  • One year ago: 18° / 16°

Every October 21 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 21 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 Bishan is sampled from the ECMWF ERA5 reanalysis at 29.59°N, 106.22°E, with daily records since 1940.

Coordinates
29.59°N, 106.22°E
Time zone
Asia/Shanghai
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

26 of the last 31 days were warmer than the historical average for that date. Average difference: +1.8°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 32.9°C and nights around 25.2°C. Roughly 95 days a year now top 30°C. In January, the coolest month, afternoons reach about 10.7°C and nights dip to 5.7°C.

Bishan picks up roughly 1,245 mm a year, with a peak of 180 mm in July and as little as 36 mm in February. A typical year brings rain or snow on around 130 days.

Over the full record (since 1940), the annual mean temperature in Bishan has risen by 1.1°C between its first decade and its last. No period since 1940 has been warmer than the most recent decade.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 20°C. Wettest month: July (~180 mm). Whole year averages ~1,245 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 130 rainy days a year: most in May (~14), fewest in February (~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.

Bishan 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
January10.7°5.7°36 mm610.3 h19.2° (1969)−3.0° (1951)
February12.9°7.2°36 mm611.0 h27.5° (2021)−3.3° (1945)
March17.9°11.1°69 mm1011.8 h33.8° (2025)0.6° (1986)
April22.9°15.5°112 mm1212.7 h36.8° (2019)3.3° (1969)
May26.3°19.4°152 mm1413.5 h39.8° (2011)10.1° (1991)
June28.9°22.5°161 mm1313.9 h39.8° (2025)14.1° (1940)
July32.5°25.4°180 mm1413.7 h42.8° (2013)18.7° (1973)
August32.9°25.2°161 mm1313.1 h44.0° (2011)19.2° (2005)
September28.0°21.5°126 mm1212.2 h43.3° (2024)13.9° (1949)
October21.8°16.5°101 mm1311.3 h36.5° (2021)7.0° (1957)
November17.0°11.8°68 mm1010.5 h28.8° (2003)−0.1° (1979)
December12.0°7.3°43 mm710.1 h21.3° (1968)−2.9° (1944)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.1°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: +0.13°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

Jun–Aug is warming fastest: +0.16°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: 75.4 early in the record → 93.2 recently. Frost days: 3 → 1.

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 2011, coldest in 1945: 44.0°C / −3.3°C.

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

Annual rainfall

~1,245 mm/year on average. Last decade: −6% vs that average. Long-term trend: −19 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 Bishan

Which is the warmest month in Bishan?
On long-term average, the warmest month in Bishan is August (mean daily temperature of about 28.8°C) and the coolest is January (about 8.4°C).
How does today's temperature in Bishan compare to the historical average?
On October 21, 2026, Bishan is forecast to reach a high of 20.8°C and a low of 17.4°C. The long-term average for this date (the full record since 1940) is a high of 21.1°C and a low of 15.9°C, so today's high is about equal to that average.
How much has Bishan warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Bishan is about 1.1°C warmer.
How much does it rain in Bishan?
Bishan receives about 1,245 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Bishan?
Over the full record (since 1940), the annual mean temperature in Bishan is about 18.9°C. The warmest month is August and the coolest is January.
What are the average temperatures in Bishan by month?
Average daily highs and lows for each month in Bishan (°C, full record since 1940): January 11°/6°, February 13°/7°, March 18°/11°, April 23°/16°, May 26°/19°, June 29°/22°, July 32°/25°, August 33°/25°, September 28°/21°, October 22°/17°, November 17°/12°, December 12°/7°.
What is the weather like in Bishan in summer?
In summer, June through August, Bishan is wet and hot. It warms from 29°C by day and 22°C at night in June to 33°C and 25°C in August. Rain is steady at around 167 mm a month, spread over roughly 13 days. No season is wetter.
What is the weather like in Bishan in winter?
Winter in Bishan (December to February) is cool. Afternoons run 11–13°C and nights 6–7°C; January is the coldest month. Rain falls on about 6 days a month, adding up to around 38 mm. No season is drier.
What is the weather like in Bishan in spring?
Spring in Bishan (March to May) is wet and pleasantly warm. It warms from 18°C by day and 11°C at night in March to 26°C and 19°C in May. Rain picks up through the season: 10 rainy days and 69 mm in March, 14 days and 152 mm in May.
What is the weather like in Bishan in autumn?
In autumn, September through November, Bishan is pleasantly warm. September is still 28°C by day and 21°C at night; by November it is down to 17°C and 12°C. Rain eases through the season: 12 rainy days and 126 mm in September, 10 days and 68 mm in November.
How many days a year does it rain in Bishan?
On long-term average, Bishan has about 130 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,245 mm.

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