Climate averages 1991–2020

Yokosuka weather
in September.

A warm, very wet month: the 3rd warmest and the 11th driest of the year.

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

Average high 25.1°C Daytime mean, September
Average low 21.7°C Night-time mean, September
Rainfall 185 mm 13 days with ≥1 mm
Daylight 12 h Sunrise to sunset, per day
Every month in Yokosuka · average highYear overview

September is a warm month in Yokosuka: daytime highs average 25.1°C and nights cool to about 21.7°C. By daytime temperature it is the 3rd warmest of the 12 months.

Expect about 185 mm of rain on roughly 13 days, which makes September a very wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 26 min on an average September day.

The nearest other city in this atlas is Yokohama (17 km away). In September its highs average 25.0°C, about as warm as Yokosuka, with 175 mm of rain.

Among the 303 cities listed in Japan, Yokosuka ranks joint 216th of 303 for the warmest September highs and joint 135th of 303 for the driest September (rainfall, lowest first). The mean September high of those 303 cities is 25.7°C; Yokosuka is 0.6°C cooler than that mean.

From September to October, average highs fall by 4.5°C to 20.6°C, and monthly rainfall rises from 185 mm to 222 mm.

The annual picture

September in context

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. 051015202530 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 2500

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

Every month, side by side

Yokosuka climate table

1991–2020
Monthly climate averages for Yokosuka, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 9.2°C4.3°C4.3°C817.410.110 h
February 9.6°C4.3°C4.3°C848.610.911 h
March 12.3°C6.9°C6.9°C14413.011.912 h
April 16.1°C11.3°C11.3°C12611.613.113 h
May 19.8°C15.7°C15.7°C13810.914.014 h
June 22.6°C19.2°C19.2°C18212.914.514 h
July 25.8°C22.8°C22.8°C14711.514.314 h
August 27.4°C24.3°C24.3°C1079.813.513 h
September, selected 25.1°C21.7°C21.7°C18513.212.412 h
October 20.6°C16.8°C16.8°C22212.711.311 h
November 16.2°C11.8°C11.8°C11510.710.310 h
December 11.7°C7.0°C7.0°C738.59.810 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

September in nearby cities

Distance from Yokosuka

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

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Yokosuka) is explained once on the Yokosuka year overview and on the Sources, method and limits page.