Kawaguchi climate

Name: Kawaguchi
Address: JP

Kawaguchi is warmest in August, with average highs of 30 °C, and coldest in January, when nights average -1.0 °C. October is the wettest month (208 mm) and December the driest (59 mm). Figures are 1991–2020 climate normals.

Across a full year Kawaguchi averages 1,458 mm of rain, 100 days above 25 °C and 49 days below freezing.

Japan · population 607,373 · 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 -1.0 °C
Driest month December 59 mm
Wettest month October 208 mm
Least cloud January 40 % cloud
Hottest on record July 40 °C
Coldest on record February -14 °C
Warmest sea August 26 °C

What to expectKawaguchi through the year

Kawaguchi has a clear annual cycle: average daily highs run from 8.2 °C in January to 30 °C in August, a swing of 23 °C in mean temperature across the year.

Counted across a normal year, 100 days a year reach 25 °C, 34 of them reach 30 °C, 49 nights drop below freezing. The warmest reading in the 1991–2020 record is 40 °C, in July.

Rain is strongly seasonal. October averages 208 mm against 59 mm in December — 3.5 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Kawaguchi is warmest in August at 26 °C and coldest in February at 13 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	8.2 °C	68 mm	40 %
February	9.2 °C	65 mm	49 %
March	12.6 °C	111 mm	58 %
April	17.7 °C	113 mm	61 %
May	22.3 °C	131 mm	69 %
June	25.1 °C	165 mm	81 %
July	28.8 °C	149 mm	75 %
August	30.3 °C	114 mm	65 %
September	26.4 °C	188 mm	68 %
October	20.9 °C	208 mm	62 %
November	15.7 °C	88 mm	53 %
December	10.6 °C	59 mm	42 %

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	8.2 °C	-1.0 °C	3.2 °C	17.7 °C	-12.3 °C	0	0	20
February	9.2 °C	-0.1 °C	4.2 °C	21.0 °C	-13.9 °C	0	0	15
March	12.6 °C	3.6 °C	7.8 °C	24.3 °C	-4.6 °C	0	0	5
April	17.7 °C	8.9 °C	13.1 °C	27.5 °C	-1.1 °C	0	0	0
May	22.3 °C	14.1 °C	18.0 °C	30.7 °C	4.3 °C	6	0	0
June	25.1 °C	18.3 °C	21.4 °C	32.9 °C	10.7 °C	16	1	0
July	28.8 °C	22.2 °C	25.2 °C	39.5 °C	15.1 °C	27	12	0
August	30.3 °C	23.5 °C	26.4 °C	37.3 °C	15.9 °C	29	17	0
September	26.4 °C	19.9 °C	22.8 °C	36.4 °C	10.0 °C	20	4	0
October	20.9 °C	13.9 °C	17.1 °C	30.4 °C	4.6 °C	3	0	0
November	15.7 °C	7.6 °C	11.3 °C	23.9 °C	-3.5 °C	0	0	0
December	10.6 °C	1.8 °C	5.9 °C	23.2 °C	-7.4 °C	0	0	9

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	68 mm	6	10 h/day	40 %	69 %	21 km/h	13.6 °C
February	65 mm	8	11 h/day	49 %	69 %	22 km/h	12.5 °C
March	111 mm	11	12 h/day	58 %	71 %	24 km/h	13.2 °C
April	113 mm	11	13 h/day	61 %	73 %	25 km/h	15.0 °C
May	131 mm	11	14 h/day	69 %	76 %	23 km/h	17.9 °C
June	165 mm	14	15 h/day	81 %	81 %	20 km/h	20.9 °C
July	149 mm	13	14 h/day	75 %	82 %	20 km/h	23.4 °C
August	114 mm	11	14 h/day	65 %	80 %	20 km/h	25.9 °C
September	188 mm	13	12 h/day	68 %	80 %	20 km/h	24.7 °C
October	208 mm	12	11 h/day	62 %	79 %	19 km/h	21.6 °C
November	88 mm	9	10 h/day	53 %	77 %	18 km/h	18.9 °C
December	59 mm	7	9.8 h/day	42 %	72 %	20 km/h	16.0 °C

How Kawaguchi 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
Kawaguchi	30 °C	-1.0 °C	1,458 mm	100
Saitama · Japan	30 °C	-1.4 °C	1,396 mm	100
Tokyo · Japan	30 °C	-0.3 °C	1,465 mm	93
Niiza · Japan	30 °C	-1.3 °C	1,599 mm	97
Matsudo · Japan	30 °C	-0.2 °C	1,478 mm	99

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

QuestionsCommon questions about Kawaguchi’s climate

When is the best time to visit Kawaguchi?

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

How hot does Kawaguchi get?

In August, the warmest month, daily highs average 30 °C. About 34 days a year pass 30 °C. The highest value in the 1991–2020 record is 40 °C.

How cold does it get in winter?

Nights average -1.0 °C in January, the coldest month. A normal year has 49 nights below freezing.

Which month is wettest in Kawaguchi?

October, averaging 208 mm over 12 days with rain. The driest month is December with 59 mm. The year as a whole averages 1,458 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 Kawaguchi 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
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.