Climate averages 1991–2020

Iwakuni weather
in January.

A cool, moderately wet month: the coolest and the driest of the year.

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

Average high 8.5°C Daytime mean, January
Average low 2.8°C Night-time mean, January
Rainfall 50 mm 6 days with ≥1 mm
Daylight 10 h Sunrise to sunset, per day
Every month in Iwakuni · average highYear overview

January is a cool month in Iwakuni: daytime highs average 8.5°C and nights cool to about 2.8°C. By daytime temperature it is the coolest month of the year.

Expect about 50 mm of rain on roughly 6 days, which makes January a moderately wet month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 10 h 09 min on an average January day.

The nearest other city in this atlas is Hatsukaichi (23 km away). In January its highs average 8.2°C, about as warm as Iwakuni, with 50 mm of rain.

Among the 303 cities listed in Japan, Iwakuni ranks joint 82nd of 303 for the warmest January highs and joint 16th of 303 for the driest January (rainfall, lowest first). The mean January high of those 303 cities is 7.0°C; Iwakuni is 1.5°C warmer than that mean.

From January to February, average highs rise by 1.1°C to 9.6°C, and monthly rainfall rises from 50 mm to 69 mm.

The annual picture

January 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. 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

Iwakuni climate table

1991–2020
Monthly climate averages for Iwakuni, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January, selected 8.5°C2.8°C2.8°C506.210.210 h
February 9.6°C2.8°C2.8°C698.010.911 h
March 13.0°C5.3°C5.3°C11610.111.912 h
April 17.8°C9.9°C9.9°C1389.713.013 h
May 22.2°C14.8°C14.8°C15810.313.914 h
June 25.1°C19.1°C19.1°C23413.914.414 h
July 28.7°C23.4°C23.4°C25515.214.214 h
August 29.8°C24.4°C24.4°C16914.413.413 h
September 26.5°C20.9°C20.9°C18511.712.412 h
October 21.5°C15.5°C15.5°C1168.011.411 h
November 16.1°C10.1°C10.1°C727.110.410 h
December 10.8°C5.1°C5.1°C606.79.910 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

January in nearby cities

Distance from Iwakuni

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 Iwakuni) is explained once on the Iwakuni year overview and on the Sources, method and limits page.

Hatsukaichi lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.