Hiroshima climate

Name: Hiroshima
Address: JP

Hiroshima is warmest in August, with average highs of 30 °C, and coldest in January, when nights average 1.6 °C. July is the wettest month (250 mm) and January the driest (56 mm). Figures are 1991–2020 climate normals.

Across a full year Hiroshima averages 1,563 mm of rain, 110 days above 25 °C and 14 days below freezing.

Japan · population 1,200,754 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month August 30 °C
Coldest month January 1.6 °C
Driest month January 56 mm
Wettest month July 250 mm
Least cloud October 52 % cloud
Hottest on record August 37 °C
Coldest on record February -4.8 °C

What to expectHiroshima through the year

Hiroshima has a clear annual cycle: average daily highs run from 8.4 °C in January to 30 °C in August, a swing of 22 °C in mean temperature across the year.

Counted across a normal year, 110 days a year reach 25 °C, 33 of them reach 30 °C, 14 nights drop below freezing. The warmest reading in the 1991–2020 record is 37 °C, in August.

Rain is strongly seasonal. July averages 250 mm against 56 mm in January — 4.5 times as much. Planning around the dry months matters more here than planning around temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	8.4 °C	56 mm	60 %
February	9.5 °C	69 mm	61 %
March	13.1 °C	110 mm	60 %
April	18.2 °C	128 mm	60 %
May	22.6 °C	142 mm	64 %
June	25.6 °C	223 mm	78 %
July	29.0 °C	250 mm	73 %
August	30.4 °C	157 mm	62 %
September	27.0 °C	185 mm	63 %
October	21.7 °C	109 mm	52 %
November	16.0 °C	70 mm	52 %
December	10.5 °C	63 mm	56 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C	Days below 0 °C
January	8.4 °C	1.6 °C	4.6 °C	16.7 °C	-4.3 °C	0	0	6
February	9.5 °C	2.0 °C	5.3 °C	19.4 °C	-4.8 °C	0	0	6
March	13.1 °C	4.6 °C	8.5 °C	21.4 °C	-1.5 °C	0	0	1
April	18.2 °C	9.4 °C	13.6 °C	26.8 °C	-0.4 °C	0	0	0
May	22.6 °C	14.2 °C	18.2 °C	29.5 °C	5.2 °C	5	0	0
June	25.6 °C	18.9 °C	22.0 °C	32.0 °C	11.0 °C	18	1	0
July	29.0 °C	23.1 °C	25.7 °C	36.3 °C	17.1 °C	29	11	0
August	30.4 °C	24.0 °C	26.9 °C	36.6 °C	17.2 °C	31	17	0
September	27.0 °C	20.1 °C	23.2 °C	35.5 °C	11.7 °C	23	4	0
October	21.7 °C	14.1 °C	17.5 °C	28.6 °C	5.0 °C	4	0	0
November	16.0 °C	8.7 °C	12.0 °C	23.7 °C	0.5 °C	0	0	0
December	10.5 °C	3.8 °C	6.9 °C	18.4 °C	-2.3 °C	0	0	1

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	56 mm	9	10 h/day	60 %	73 %	15 km/h
February	69 mm	9	11 h/day	61 %	72 %	15 km/h
March	110 mm	12	12 h/day	60 %	72 %	15 km/h
April	128 mm	11	13 h/day	60 %	72 %	14 km/h
May	142 mm	11	14 h/day	64 %	75 %	13 km/h
June	223 mm	15	14 h/day	78 %	81 %	12 km/h
July	250 mm	16	14 h/day	73 %	85 %	13 km/h
August	157 mm	14	13 h/day	62 %	81 %	12 km/h
September	185 mm	13	12 h/day	63 %	79 %	13 km/h
October	109 mm	8	11 h/day	52 %	76 %	13 km/h
November	70 mm	8	10 h/day	52 %	76 %	13 km/h
December	63 mm	9	9.9 h/day	56 %	75 %	15 km/h

How Hiroshima compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Hiroshima	30 °C	1.6 °C	1,563 mm	110
Kure · Japan	29 °C	3.4 °C	1,527 mm	82
Higashihiroshima · Japan	29 °C	0.3 °C	1,413 mm	94
Imabari · Japan	30 °C	4.2 °C	1,653 mm	100
Matsuyama · Japan	31 °C	3.4 °C	1,697 mm	115
Fukuyama · Japan	31 °C	2.1 °C	1,257 mm	114
Yamaguchi · Japan	30 °C	1.6 °C	1,692 mm	106

Planning a trip? See the best time to visit Hiroshima.

QuestionsCommon questions about Hiroshima’s climate

When is the best time to visit Hiroshima?

That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, October sit closest to 20 °C on average, August is the warmest month and January the driest. The month-by-month table above has the full picture.

How hot does Hiroshima get?

In August, the warmest month, daily highs average 30 °C. About 33 days a year pass 30 °C. The highest value in the 1991–2020 record is 37 °C.

How cold does it get in winter?

Nights average 1.6 °C in January, the coldest month. A normal year has 14 nights below freezing.

Which month is wettest in Hiroshima?

July, averaging 250 mm over 16 days with rain. The driest month is January with 56 mm. The year as a whole averages 1,563 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Hiroshima rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: 34.400°, 132.450° (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.