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Kisarazu weather by month: averages, rainfall & climate trends

Seasons run to extremes in Kisarazu: monthly means span 20.1°C between the coldest month and the warmest. The heaviest rain tends to come in September and October. Kisarazu weather by month: average temperatures, rainfall, records and how the climate has changed since 1940.

Today vs average

+3.5°Chigh well above average

24° / 18°Today
21° / 17°Average
see today in detail →

How it's changed

+1.6°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–491frost days a year now (2016–2025) · 5 in the 1940sfrost days a year · 5 in the 1940s30days above 30°C a year now (2016–2025) · 5 in the 1940sdays above 30°C · 5 in the 1940s+1.6°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 75 mmhigh 8°low 4°February, rain 87 mmhigh 9°low 4°March, rain 138 mmhigh 12°low 6°April, rain 141 mmhigh 16°low 12°May, rain 156 mmhigh 20°low 16°June, rain 192 mmhigh 23°low 19°July, rain 145 mmhigh 27°low 23°August, rain 131 mmhigh 28°low 24°September, rain 207 mmhigh 25°low 22°October, rain 229 mmhigh 20°low 16°November, rain 128 mmhigh 16°low 11°December, rain 73 mmhigh 11°low 6°wettest month October, 229 mm · 1,702 mm a yearsee month by month →

Right now

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

Right now

19.6°

22°feels like
94%humidity
19°dew point
3 km/hfrom NE
UV index0.0
sunrise05:47sunset17:04day length11h 18m
TodayOvercast24°18°
SatMostly clear23°16°
SunPartly cloudy23°15°
MonOvercast25°15°
TueOvercast27°22°
WedPartly cloudy27°21°
ThuOvercast24°19°

On this date: October 16

Today (forecast)
24° / 18°
Average for October 16
21° / 17°

High well above average · +3.5°C

  • Record high: 24.9° · 2024
  • Record low: 12.7° · 1982
  • One year ago: 22° / 19°

Every October 16 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 16 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 Kisarazu is sampled from the ECMWF ERA5 reanalysis at 35.38°N, 139.93°E, with daily records since 1940.

Coordinates
35.38°N, 139.93°E
Time zone
Asia/Tokyo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

20 of the last 31 days were warmer than the historical average for that date. Average difference: +0.8°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

The warmest month is August, with typical afternoon highs of 28.5°C and nights around 24.5°C. On about 115 nights a year, the temperature never drops below 20°C. At the other extreme, January brings afternoon highs of about 8.4°C and typical overnight lows of 3.5°C.

Kisarazu picks up roughly 1,702 mm a year, with a peak of 229 mm in October and as little as 73 mm in December. A typical year brings rain or snow on around 124 days.

Over the full record (since 1940), the annual mean temperature in Kisarazu has risen by 1.6°C between its first decade and its last. Days above 30°C have grown noticeably more frequent, from around 5 a year in the first decade to about 30 in the last.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 20°C. Wettest month: October (~229 mm). Whole year averages ~1,702 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 124 rainy days a year: most in September (~14), fewest in January (~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.

Kisarazu 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
January8.4°3.5°75 mm69.9 h18.0° (1969)−2.0° (1954)
February8.8°3.6°87 mm710.7 h19.4° (2009)−3.0° (1952)
March11.7°6.5°138 mm1111.7 h21.7° (2025)−0.7° (1971)
April16.3°11.5°141 mm1112.9 h25.1° (1998)3.7° (2015)
May20.3°15.9°156 mm1113.9 h29.5° (2023)7.8° (1953)
June23.3°19.4°192 mm1314.4 h32.1° (1991)13.2° (1958)
July26.9°22.9°145 mm1114.2 h36.5° (2018)15.1° (1976)
August28.5°24.5°131 mm1113.3 h35.5° (2013)19.2° (2003)
September25.5°21.7°207 mm1412.2 h32.1° (2010)14.6° (2001)
October20.4°16.3°229 mm1311.1 h28.4° (2019)9.2° (1983)
November15.7°11.1°128 mm1010.1 h23.5° (2023)3.2° (2016)
December11.0°6.2°73 mm79.6 h22.0° (2004)−0.2° (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 +1.6°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: +0.17°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: +0.20°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: 5.2 early in the record → 29.8 recently. Frost days: 5 → 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

All-time high in 2018, all-time low in 1952: 36.5°C / −3.0°C.

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

Annual rainfall

~1,702 mm/year on average. Last decade: +5% vs that average. Long-term trend: +45 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 Kisarazu

Which is the warmest month in Kisarazu?
On long-term average, the warmest month in Kisarazu is August (mean daily temperature of about 26.1°C) and the coolest is January (about 6.0°C).
How does today's temperature in Kisarazu compare to the historical average?
On October 16, 2026, Kisarazu is forecast to reach a high of 24.3°C and a low of 18.3°C. The long-term average for this date (the full record since 1940) is a high of 20.8°C and a low of 16.5°C, so today's high is 3.5°C warmer than that average.
How much has Kisarazu warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Kisarazu is about 1.6°C warmer.
How much does it rain in Kisarazu?
Kisarazu receives about 1,702 mm of precipitation per year on long-term average, with October typically the wettest month.
What is the average temperature in Kisarazu?
Over the full record (since 1940), the annual mean temperature in Kisarazu is about 15.8°C. The warmest month is August and the coolest is January.
What are the average temperatures in Kisarazu by month?
Average daily highs and lows for each month in Kisarazu (°C, full record since 1940): January 8°/4°, February 9°/4°, March 12°/6°, April 16°/12°, May 20°/16°, June 23°/19°, July 27°/23°, August 28°/24°, September 25°/22°, October 20°/16°, November 16°/11°, December 11°/6°.
What is the weather like in Kisarazu in summer?
June to August is summer in Kisarazu, and it is wet and warm. June starts at 23°C by day and 19°C at night; by August it is 28°C and 24°C. Rain is steady at around 156 mm a month, spread over roughly 11 days.
What is the weather like in Kisarazu in winter?
December to February is winter in Kisarazu, and it is on the cool side. Afternoons run 8–11°C and nights 4–6°C; January is the coldest month. Rain falls on about 7 days a month, adding up to around 78 mm. No season is drier.
What is the weather like in Kisarazu in spring?
March to May is spring in Kisarazu, and it is wet and fairly mild. It warms from 12°C by day and 6°C at night in March to 20°C and 16°C in May. Rain is steady at around 145 mm a month, spread over roughly 11 days.
What is the weather like in Kisarazu in autumn?
In autumn, September through November, Kisarazu is wet and mild. It cools from 25°C by day and 22°C at night in September to 16°C and 11°C in November. Rain eases through the season: 14 rainy days and 207 mm in September, 10 days and 128 mm in November. No season is wetter.
How many days a year does it rain in Kisarazu?
On long-term average, Kisarazu has about 124 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,702 mm.

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