Nagano climate

Name: Nagano
Address: JP

Nagano is warmest in August, with average highs of 28 °C, and coldest in January, when nights average -4.4 °C. July is the wettest month (229 mm) and November the driest (111 mm). Figures are 1991–2020 climate normals.

Across a full year Nagano averages 1,778 mm of rain, 77 days above 25 °C and 102 days below freezing.

Japan · population 372,760 · 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 28 °C
Coldest month January -4.4 °C
Driest month November 111 mm
Wettest month July 229 mm
Least cloud April 63 % cloud
Hottest on record August 37 °C
Coldest on record February -16 °C

What to expectNagano through the year

Nagano has a clear annual cycle: average daily highs run from 2.4 °C in January to 28 °C in August, a swing of 25 °C in mean temperature across the year.

Counted across a normal year, 77 days a year reach 25 °C, 16 of them reach 30 °C, 102 nights drop below freezing. The warmest reading in the 1991–2020 record is 37 °C, in August.

Rain is strongly seasonal. July averages 229 mm against 111 mm in November — 2.1 times as much. Planning around the dry months matters more here than planning around temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	2.4 °C	138 mm	70 %
February	3.5 °C	118 mm	69 %
March	7.4 °C	132 mm	66 %
April	14.1 °C	112 mm	63 %
May	20.7 °C	129 mm	68 %
June	23.8 °C	175 mm	79 %
July	27.0 °C	229 mm	78 %
August	28.3 °C	163 mm	69 %
September	24.0 °C	181 mm	73 %
October	18.1 °C	160 mm	66 %
November	12.1 °C	111 mm	63 %
December	5.5 °C	131 mm	67 %

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	2.4 °C	-4.4 °C	-1.5 °C	13.2 °C	-16.0 °C	0	0	28
February	3.5 °C	-3.9 °C	-0.8 °C	16.5 °C	-16.3 °C	0	0	25
March	7.4 °C	-0.9 °C	2.6 °C	21.2 °C	-10.0 °C	0	0	19
April	14.1 °C	3.9 °C	8.5 °C	26.2 °C	-4.8 °C	0	0	4
May	20.7 °C	10.2 °C	15.1 °C	32.2 °C	0.1 °C	4	0	0
June	23.8 °C	15.1 °C	19.1 °C	32.3 °C	6.4 °C	10	0	0
July	27.0 °C	19.2 °C	22.8 °C	34.5 °C	12.5 °C	23	5	0
August	28.3 °C	20.0 °C	23.7 °C	36.7 °C	11.9 °C	27	9	0
September	24.0 °C	16.1 °C	19.5 °C	34.6 °C	4.9 °C	12	1	0
October	18.1 °C	9.8 °C	13.4 °C	29.7 °C	-0.7 °C	1	0	0
November	12.1 °C	3.6 °C	7.2 °C	23.3 °C	-5.5 °C	0	0	4
December	5.5 °C	-2.0 °C	1.2 °C	21.8 °C	-10.9 °C	0	0	22

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	138 mm	21	9.9 h/day	70 %	79 %	10 km/h
February	118 mm	18	11 h/day	69 %	78 %	11 km/h
March	132 mm	17	12 h/day	66 %	77 %	11 km/h
April	112 mm	14	13 h/day	63 %	76 %	11 km/h
May	129 mm	14	14 h/day	68 %	76 %	10 km/h
June	175 mm	18	15 h/day	79 %	82 %	9.1 km/h
July	229 mm	21	14 h/day	78 %	86 %	8.2 km/h
August	163 mm	18	14 h/day	69 %	83 %	8.5 km/h
September	181 mm	17	12 h/day	73 %	85 %	9.4 km/h
October	160 mm	15	11 h/day	66 %	84 %	9.6 km/h
November	111 mm	16	10 h/day	63 %	83 %	9.6 km/h
December	131 mm	20	9.7 h/day	67 %	81 %	9.7 km/h

How Nagano 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
Nagano	28 °C	-4.4 °C	1,778 mm	77
Ueda · Japan	29 °C	-4.5 °C	1,513 mm	81
Matsumoto · Japan	28 °C	-5.9 °C	1,831 mm	80
Jōetsu · Japan	29 °C	-0.6 °C	2,259 mm	86
Takasaki · Japan	28 °C	-2.4 °C	1,936 mm	78
Maebashi · Japan	29 °C	-2.0 °C	1,577 mm	83
Toyama · Japan	29 °C	-2.6 °C	2,254 mm	79

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

QuestionsCommon questions about Nagano’s climate

When is the best time to visit Nagano?

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

How hot does Nagano get?

In August, the warmest month, daily highs average 28 °C. About 16 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 -4.4 °C in January, the coldest month. A normal year has 102 nights below freezing.

Which month is wettest in Nagano?

July, averaging 229 mm over 21 days with rain. The driest month is November with 111 mm. The year as a whole averages 1,778 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 Nagano 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: 36.650°, 138.183° (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.