Climate averages 1991–2020

Kisarazu weather
by month.

See how the year changes. August has the highest average daily maximum; December has the lowest average monthly rainfall.

Long-term climate patterns, not a forecast for a particular trip.

Warmest month 29.0°C August, average high
Coolest month 3.1°C January, average low
Wettest month 251 mm October, monthly total
Driest month 80 mm December, monthly total
The year at a glance · average highYear overview

Across the year Kisarazu averages a daytime high of 18.8°C and a nighttime low of 13.2°C, with about 1,731 mm of rain on roughly 143 days. August is the warmest month (average high 29.0°C) and January the coolest (9.1°C). October is the wettest month with 251 mm; December is the driest with 80 mm.

The annual picture

A year in Kisarazu

30-year average
Average highAverage low°C
Average daily high and low temperatures by month The same values are available in the monthly table below. Lines show mean daily maxima and minima, not a forecast interval. 05101520253035 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly rainfall

Average total · mm
Average monthly rainfall totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 3000

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Kisarazu climate table

1991–2020
Monthly climate averages for Kisarazu, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 9.1°C3.1°C3.1°C867.810.110 h
February 9.8°C3.2°C3.2°C838.810.911 h
March 12.8°C6.0°C6.0°C14913.011.912 h
April 17.2°C10.5°C10.5°C13812.913.113 h
May 21.2°C15.2°C15.2°C14912.114.014 h
June 24.0°C18.8°C18.8°C18914.314.515 h
July 27.5°C22.6°C22.6°C15512.914.314 h
August 29.0°C24.1°C24.1°C11811.513.513 h
September 26.0°C21.3°C21.3°C20714.712.412 h
October 21.1°C16.2°C16.2°C25114.411.311 h
November 16.2°C11.0°C11.0°C12611.810.310 h
December 11.5°C5.9°C5.9°C808.79.810 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

Nearby cities

Distance from Kisarazu

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits
What do the high and low temperatures mean?

We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.

How is a rain day counted?

A local calendar day (standard time, UTC+9, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.

Where do the numbers come from?

ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 35.40°, 139.90° (4 km from the city centre), adjusted down by 0.1°C for the difference between the city's elevation (5 m) and the cell's (-6 m). Rain comes from the 0.25° cell at 35.50°, 140.00°. Chiba and Ichihara lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells. These are model estimates, not weather-station readings; coast, hills and city streets can differ.

Does this page show sunshine, humidity or sea temperature?

No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.