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Tsukuba weather by month: averages, rainfall & climate trends

Tsukuba swings through a wide annual range, with 23.1°C between the monthly means of its warmest and coldest months. Rainfall leans toward the stretch from May to October. Tsukuba weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+4.4°Chigh well above average

24° / 15°Today
20° / 12°Average
see today in detail →

How it's changed

+2.5°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4936frost days a year now (2016–2025) · 73 in the 1940sfrost days a year · 73 in the 1940s59days above 30°C a year now (2016–2025) · 26 in the 1940sdays above 30°C · 26 in the 1940s+2.5°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 51 mmhigh 8°low 0°February, rain 59 mmhigh 9°low 0°March, rain 99 mmhigh 13°low 4°April, rain 108 mmhigh 18°low 10°May, rain 131 mmhigh 22°low 15°June, rain 163 mmhigh 25°low 19°July, rain 153 mmhigh 29°low 22°August, rain 136 mmhigh 30°low 24°September, rain 173 mmhigh 26°low 20°October, rain 164 mmhigh 21°low 14°November, rain 85 mmhigh 16°low 8°December, rain 51 mmhigh 11°low 2°wettest month September, 173 mm · 1,373 mm a yearsee month by month →

Right now

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

Right now

19.5°

18°feels like
56%humidity
11°dew point
15 km/hfrom NE
UV index0.5
sunrise05:52sunset16:55day length11h 03m
ThuOvercast24°15°
FriOvercast20°13°
SatLight rain18°16°
SunOvercast20°17°
MonOvercast20°16°
TuePartly cloudy26°18°
WedClear17°12°

On this date: October 21

Today (forecast)
24° / 15°
Average for October 21
20° / 12°

High well above average · +4.4°C

  • Highest since 1940: 25.4° · 1976
  • Lowest since 1940: 7.7° · 1992
  • One year ago: 16° / 12°

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 Tsukuba is sampled from the ECMWF ERA5 reanalysis at 36.08°N, 140.12°E, with daily records since 1940.

Coordinates
36.08°N, 140.12°E
Time zone
Asia/Tokyo
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: +1.7°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

August brings the year's peak warmth, with afternoons typically reaching 30.5°C and nights around 23.7°C. Roughly 60 days a year now top 30°C. In January, the coolest month, afternoons reach about 8.3°C and nights dip to −0.4°C.

The yearly total for Tsukuba comes to about 1,373 mm; monthly amounts range from 51 mm in December up to 173 mm in September.

Comparing the record's first decade with its most recent one, Tsukuba now averages 2.5°C warmer than it did in the 1940s. Frost days have thinned out, from around 75 a year in the first decade to about 35 now.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 23°C. Wettest month: September (~173 mm). Whole year averages ~1,373 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 113 rainy days a year: most in June (~13), fewest in January (~5).

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.

Tsukuba 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°−0.4°51 mm59.8 h20.9° (1969)−11.0° (1954)
February9.0°0.3°59 mm610.7 h24.9° (1962)−15.1° (1967)
March12.6°3.9°99 mm1011.7 h26.4° (2024)−6.9° (1970)
April18.0°9.7°108 mm1012.9 h28.5° (2025)−2.2° (1941)
May22.4°14.5°131 mm1113.9 h32.9° (2019)3.7° (1953)
June25.2°18.6°163 mm1314.4 h37.3° (2022)9.7° (1952)
July29.0°22.5°153 mm1314.2 h38.0° (1990)12.2° (1976)
August30.5°23.7°136 mm1213.4 h40.0° (1994)16.6° (2018)
September26.5°20.1°173 mm1312.2 h37.2° (1984)10.5° (1960)
October20.9°13.8°164 mm1111.1 h32.3° (2018)4.0° (1942)
November15.8°7.7°85 mm710.0 h26.0° (2023)−5.4° (2016)
December10.8°2.0°51 mm59.6 h25.2° (2004)−5.7° (1981)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +2.5°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: +0.28°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: +0.32°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: 25.5 early in the record → 59.1 recently. Frost days: 73 → 36.

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 1994, coldest in 1967: 40.0°C / −15.1°C.

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

Annual rainfall

~1,373 mm/year on average. Last decade: +2% vs that average. Long-term trend: +30 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 Tsukuba

Which is the warmest month in Tsukuba?
On long-term average, the warmest month in Tsukuba is August (mean daily temperature of about 26.6°C) and the coolest is January (about 3.5°C).
How does today's temperature in Tsukuba compare to the historical average?
On October 21, 2026, Tsukuba is forecast to reach a high of 24.1°C and a low of 15.4°C. The long-term average for this date (the full record since 1940) is a high of 19.7°C and a low of 12.5°C, so today's high is 4.4°C warmer than that average.
How much has Tsukuba warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Tsukuba is about 2.5°C warmer.
How much does it rain in Tsukuba?
Tsukuba receives about 1,373 mm of precipitation per year on long-term average, with September typically the wettest month.
What is the average temperature in Tsukuba?
Over the full record (since 1940), the annual mean temperature in Tsukuba is about 14.9°C. The warmest month is August and the coolest is January.
What are the average temperatures in Tsukuba by month?
Average daily highs and lows for each month in Tsukuba (°C, full record since 1940): January 8°/0°, February 9°/0°, March 13°/4°, April 18°/10°, May 22°/15°, June 25°/19°, July 29°/22°, August 30°/24°, September 26°/20°, October 21°/14°, November 16°/8°, December 11°/2°.
What is the weather like in Tsukuba in summer?
In summer, June through August, Tsukuba is wet and warm. It warms from 25°C by day and 19°C at night in June to 30°C and 24°C in August. Rain falls on about 12 days a month, adding up to around 151 mm.
What is the weather like in Tsukuba in winter?
In winter, December through February, Tsukuba is on the cool side. Afternoons run 8–11°C and nights 0–2°C; January is the coldest month. Rain is steady at around 54 mm a month, spread over roughly 5 days. No season is drier.
What is the weather like in Tsukuba in spring?
March to May is spring in Tsukuba, and it is wet and fairly mild. March starts at 13°C by day and 4°C at night; by May it is 22°C and 15°C. Rain falls on about 10 days a month, adding up to around 113 mm.
What is the weather like in Tsukuba in autumn?
In autumn, September through November, Tsukuba is wet and mild. September is still 26°C by day and 20°C at night; by November it is down to 16°C and 8°C. Rain eases through the season: 13 rainy days and 173 mm in September, 7 days and 85 mm in November.
How many days a year does it rain in Tsukuba?
On long-term average, Tsukuba has about 113 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,373 mm.

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