Niitsu climate — normals and trends

Q: What is the climate of Niitsu?

Niitsu has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 13.6 °C and it receives 1,733 mm of precipitation per year.

Q: What is the hottest day ever recorded in Niitsu?

The hottest day measured in Niitsu between 1940 and 2025 was 23 August 2018, reaching 38.4 °C.

Q: What is the coldest day in Niitsu?

The coldest day measured in Niitsu between 1940 and 2025 was 1 February 1948, at -9.7 °C.

Q: Does it snow in Niitsu?

Yes. Niitsu gets on average 157.1 cm of snow per year and has around 41 frost days.

Q: Has the climate of Niitsu warmed?

Yes: Niitsu warmed by +2.6 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in Niitsu?

The wettest day measured in Niitsu between 1940 and 2025 was 6 August 1976, with 144 mm of rain in 24 hours.

Q: What was the windiest day in Niitsu?

The windiest day measured in Niitsu between 1940 and 2025 was 16 September 1961, with winds reaching 63.4 km/h.

Q: What is the warmest month in Niitsu?

The warmest month in Niitsu is August (26.2 °C on average); the coldest is January (2.4 °C).

Q: How much does it rain in Niitsu?

Niitsu receives on average 1,733 mm of precipitation per year, spread over about 210 rainy days.

Q: Is it sunny in Niitsu?

Niitsu gets on average 8.4 hours of sunshine per day, roughly 3,066 hours per year over 1940-2025.

Niitsu (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 13.6 °C and it receives 1,733 mm of precipitation per year.

These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.

The warmest month is August (26.2 °C on average) and the coldest is January (2.4 °C). Rainfall peaks in July.

Niitsu averages 41 frost days, 27 hot days (≥ 30 °C) and 210 rainy days per year.

Niitsu has warmed by +2.6 °C between 1940 and 2025, or +0.31 °C per decade. This trend is statistically significant.

The number of frost days there went from about 69 to 13 per year over the period.

The hottest day of the period reached 38.4 °C (on 23 August 2018) and the coldest -9.7 °C (on 1 February 1948).

Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.

Climate normals · ERA5

NiitsuNiigata

coords: 37.80°, 139.12°
period: 1940–2025 · 86 yrs

CfaHumid subtropicalWarmest monthAugustColdest monthJanuaryWettest monthJulyDriest monthApril

Mean daily temperature

13.6°C

Average daily high

17.0°C

Average daily low

10.2°C

Annual rainfall

1,733mm

Sunshine / day

8.4h

Mean relative humidity

76%

Average peak wind

16.2km/h

Seasonal range

23.8°C

Frost days (< 0 °C)

41 d/yr

Hot days (≥ 30 °C)

27 d/yr

Rainy days (≥ 1 mm)

210 d/yr

Annual snowfall

157.1 cm

Average feels-like high

16.7 °C

Average feels-like low

8.9 °C

Average peak gust

36.3 km/h

Tropical nights (≥ 20 °C)

68 d/yr

Solar radiation

13.8 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+2.6 °C

since 1940

+0.3 °C per decade · r² = 0.67 · p = < 0.001

19402025

Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).

A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.

Records for the period

Hottest day

38.4 °C

23 August 2018

Coldest day

-9.7 °C

1 February 1948

Wettest day

144 mm

6 August 1976

Windiest day

63.4 km/h

16 September 1961

Strongest gust

135.4 km/h

16 September 1961

Hottest feels-like

45.1 °C

23 August 2023

Coldest feels-like

-14.7 °C

12 February 1942

Snowiest day

21.9 cm

15 February 2014

Sunniest day

14.1 h

11 June 1940

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days	Frost days
2025	35.0 °C4 August 2025	-2.7 °C21 February 2025	14.7 °C	1,926 mm	61	23
2024	35.8 °C23 August 2024	-3.2 °C11 January 2024	15.4 °C	1,978 mm	51	13
2023	38.0 °C23 August 2023	-4.1 °C25 January 2023	15.8 °C	1,744 mm	67	25
2022	36.2 °C6 September 2022	-2.0 °C19 January 2022	14.9 °C	1,855 mm	51	15
2021	36.4 °C3 August 2021	-4.5 °C21 January 2021	14.9 °C	1,790 mm	36	30
2020	37.5 °C3 September 2020	-4.2 °C12 February 2020	15.1 °C	2,040 mm	35	7
2019	37.3 °C15 August 2019	-4.0 °C15 February 2019	14.9 °C	1,706 mm	37	15
2018	38.4 °C23 August 2018	-6.6 °C15 January 2018	14.8 °C	1,647 mm	48	41
2017	36.8 °C7 August 2017	-2.3 °C15 January 2017	14.1 °C	1,991 mm	28	15
2016	34.9 °C7 August 2016	-5.4 °C15 January 2016	14.9 °C	1,515 mm	31	18
2015	36.3 °C13 July 2015	-2.5 °C21 January 2015	14.8 °C	1,342 mm	29	12
2014	34.9 °C26 July 2014	-5.0 °C15 January 2014	14.1 °C	1,577 mm	24	33
2013	34.5 °C31 August 2013	-4.3 °C26 February 2013	14.1 °C	1,964 mm	28	42
2012	37.5 °C17 September 2012	-4.5 °C25 December 2012	14.1 °C	1,503 mm	47	42
2011	35.2 °C20 July 2011	-5.1 °C3 February 2011	14.0 °C	1,671 mm	45	44
2010	34.6 °C5 August 2010	-5.3 °C22 February 2010	14.5 °C	1,750 mm	53	29
2009	33.5 °C15 July 2009	-3.8 °C28 January 2009	14.2 °C	1,567 mm	11	24
2008	34.5 °C3 August 2008	-4.7 °C19 January 2008	14.4 °C	1,422 mm	23	25
2007	36.2 °C3 August 2007	-3.5 °C5 February 2007	14.6 °C	1,605 mm	28	13
2006	36.8 °C17 August 2006	-6.0 °C10 January 2006	14.1 °C	1,652 mm	28	35
2005	34.0 °C7 September 2005	-4.3 °C8 February 2005	14.1 °C	1,702 mm	32	37
2004	37.0 °C5 July 2004	-6.4 °C11 February 2004	14.8 °C	1,829 mm	36	20
2003	34.8 °C13 September 2003	-4.8 °C5 February 2003	14.0 °C	1,442 mm	11	29
2002	35.0 °C1 September 2002	-4.4 °C31 December 2002	14.2 °C	1,986 mm	31	18
2001	33.3 °C9 September 2001	-4.9 °C12 March 2001	14.0 °C	1,701 mm	29	36
2000	36.0 °C31 August 2000	-6.0 °C27 January 2000	14.3 °C	1,671 mm	47	27
1999	35.8 °C6 August 1999	-4.6 °C5 February 1999	14.5 °C	1,857 mm	35	26
1998	34.5 °C26 July 1998	-4.6 °C19 February 1998	14.8 °C	1,909 mm	19	19
1997	35.1 °C9 August 1997	-3.2 °C22 January 1997	14.0 °C	1,811 mm	20	19
1996	33.9 °C14 August 1996	-6.1 °C25 February 1996	13.2 °C	1,689 mm	25	40
1995	34.1 °C24 July 1995	-5.1 °C17 January 1995	13.6 °C	1,830 mm	23	32
1994	36.2 °C11 August 1994	-2.1 °C17 December 1994	14.7 °C	1,259 mm	48	21
1993	33.1 °C4 September 1993	-3.2 °C23 January 1993	13.5 °C	1,845 mm	7	10
1992	34.0 °C25 August 1992	-5.5 °C12 February 1992	14.0 °C	1,500 mm	26	18
1991	34.0 °C26 July 1991	-4.5 °C14 February 1991	14.2 °C	1,903 mm	15	21
1990	36.7 °C22 August 1990	-4.9 °C21 January 1990	15.0 °C	1,440 mm	35	25
1989	34.9 °C26 July 1989	-1.7 °C16 January 1989	14.4 °C	1,592 mm	26	11
1988	33.1 °C10 August 1988	-4.9 °C7 January 1988	13.2 °C	1,767 mm	22	34
1987	35.7 °C31 August 1987	-5.2 °C22 February 1987	14.1 °C	1,371 mm	21	32
1986	35.3 °C29 August 1986	-4.2 °C20 January 1986	13.0 °C	1,560 mm	23	47
1985	34.9 °C11 August 1985	-5.6 °C16 December 1985	13.5 °C	1,874 mm	44	57
1984	35.6 °C22 August 1984	-4.1 °C6 February 1984	12.9 °C	1,549 mm	38	68
1983	34.5 °C14 August 1983	-5.5 °C15 February 1983	13.5 °C	2,097 mm	24	29
1982	35.5 °C28 August 1982	-5.0 °C16 January 1982	13.8 °C	1,552 mm	13	37
1981	34.5 °C30 July 1981	-3.5 °C27 February 1981	12.9 °C	1,803 mm	24	32
1980	34.4 °C11 September 1980	-2.9 °C28 March 1980	12.9 °C	1,919 mm	9	33
1979	34.4 °C27 August 1979	-4.3 °C10 February 1979	14.1 °C	1,800 mm	14	38
1978	34.9 °C3 August 1978	-8.5 °C17 February 1978	13.6 °C	1,833 mm	39	37
1977	33.7 °C4 August 1977	-4.8 °C4 January 1977	13.2 °C	1,614 mm	21	56
1976	32.8 °C25 July 1976	-7.2 °C14 February 1976	12.7 °C	2,247 mm	12	45
1975	35.4 °C18 August 1975	-6.0 °C18 February 1975	13.6 °C	1,726 mm	39	44
1974	33.8 °C2 September 1974	-5.1 °C22 February 1974	12.9 °C	1,796 mm	17	43
1973	35.1 °C18 August 1973	-2.7 °C4 February 1973	13.6 °C	1,634 mm	42	34
1972	34.1 °C25 July 1972	-5.0 °C26 February 1972	13.9 °C	2,073 mm	24	24
1971	36.3 °C6 August 1971	-6.1 °C21 February 1971	12.9 °C	2,064 mm	19	51
1970	34.2 °C22 August 1970	-6.3 °C13 March 1970	12.9 °C	1,751 mm	33	69
1969	32.9 °C4 August 1969	-5.9 °C28 February 1969	12.9 °C	2,074 mm	15	54
1968	34.5 °C30 July 1968	-6.2 °C24 February 1968	13.4 °C	1,713 mm	19	42
1967	32.7 °C22 August 1967	-9.1 °C15 February 1967	13.4 °C	1,795 mm	23	63
1966	33.3 °C23 August 1966	-6.0 °C23 January 1966	12.5 °C	1,900 mm	22	67
1965	34.3 °C6 August 1965	-8.9 °C3 March 1965	12.1 °C	1,815 mm	10	67
1964	33.9 °C16 August 1964	-4.5 °C27 February 1964	13.6 °C	2,060 mm	32	26
1963	34.5 °C10 August 1963	-4.3 °C12 March 1963	13.5 °C	1,858 mm	20	43
1962	35.1 °C3 August 1962	-3.7 °C14 February 1962	13.7 °C	1,563 mm	33	24
1961	35.0 °C4 September 1961	-4.2 °C25 February 1961	14.2 °C	2,110 mm	41	41
1960	35.4 °C29 August 1960	-6.6 °C12 February 1960	13.7 °C	1,862 mm	29	35
1959	33.2 °C8 July 1959	-3.9 °C9 January 1959	14.1 °C	1,955 mm	16	25
1958	32.5 °C18 August 1958	-4.8 °C1 March 1958	13.6 °C	1,989 mm	13	40
1957	35.7 °C21 August 1957	-5.5 °C3 February 1957	13.1 °C	1,678 mm	20	48
1956	34.4 °C10 September 1956	-4.8 °C27 February 1956	13.1 °C	1,988 mm	18	45
1955	34.9 °C16 July 1955	-4.6 °C7 February 1955	13.9 °C	1,874 mm	35	28
1954	34.3 °C14 September 1954	-3.6 °C13 January 1954	13.5 °C	1,482 mm	26	34
1953	32.5 °C30 July 1953	-4.4 °C28 January 1953	13.1 °C	2,122 mm	11	37
1952	31.3 °C19 August 1952	-8.1 °C19 February 1952	11.6 °C	1,764 mm	4	85
1951	34.5 °C19 August 1951	-9.1 °C6 March 1951	12.3 °C	1,375 mm	16	67
1950	35.3 °C20 August 1950	-7.2 °C14 January 1950	13.0 °C	1,404 mm	42	66
1949	33.5 °C29 July 1949	-4.9 °C27 December 1949	12.5 °C	1,552 mm	17	63
1948	32.5 °C9 September 1948	-9.7 °C1 February 1948	12.8 °C	1,336 mm	14	63
1947	31.6 °C19 July 1947	-6.8 °C29 January 1947	11.3 °C	1,666 mm	6	101
1946	32.7 °C29 July 1946	-6.4 °C11 February 1946	12.5 °C	1,490 mm	22	82
1945	32.7 °C26 August 1945	-7.7 °C22 February 1945	11.8 °C	2,192 mm	11	88
1944	31.9 °C22 August 1944	-9.4 °C24 February 1944	12.3 °C	1,541 mm	8	97
1943	32.0 °C28 August 1943	-7.7 °C10 January 1943	12.1 °C	1,327 mm	17	93
1942	32.8 °C31 August 1942	-9.3 °C12 February 1942	12.2 °C	1,318 mm	23	87
1941	33.3 °C23 August 1941	-7.5 °C12 February 1941	11.9 °C	1,433 mm	8	89
1940	31.6 °C25 August 1940	-7.9 °C17 January 1940	11.8 °C	1,542 mm	4	88

Normals computed over complete calendar years 1940–2025.

A specific year

Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?

Year

Across the whole year

Average daily high

18.3 °C

+1.3 °C

Hot days (≥ 30 °C)

61 d/yr

+34

Frost days (< 0 °C)

23 d/yr

-18

Annual rainfall

1926 mm

+193 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	5.7 °C	+1.0 °C	211 mm	+44 mm
Feb	4.8 °C	-0.4 °C	158 mm	+34 mm
Mar	10.7 °C	+1.7 °C	108 mm	-10 mm
Apr	15.5 °C	0.0 °C	110 mm	+16 mm
May	20.8 °C	+0.2 °C	146 mm	+48 mm
Jun	26.1 °C	+1.9 °C	107 mm	-17 mm
Jul	31.8 °C	+3.9 °C	12 mm	-200 mm
Aug	30.9 °C	+1.3 °C	247 mm	+92 mm
Sep	28.1 °C	+2.5 °C	243 mm	+85 mm
Oct	20.3 °C	+0.7 °C	200 mm	+58 mm
Nov	14.3 °C	+0.5 °C	184 mm	+31 mm
Dec	9.5 °C	+1.5 °C	203 mm	+14 mm

The year's extremes

Hottest day

35.0 °C

4 Aug 2025

Coldest day

-2.7 °C

21 Feb 2025

Wettest day

61.8 mm

12 Aug 2025

Windiest day

39.5 km/h

16 Apr 2025

Strongest gust

90.0 km/h

14 Dec 2025

Hottest feels-like

41.8 °C

25 Aug 2025

Coldest feels-like

-7.3 °C

8 Feb 2025

Snowiest day

10.9 cm

7 Feb 2025

Sunniest day

14.0 h

5 Jun 2025

What was the weather like that day?

Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.

Date

Frequently asked questions

What is the climate of Niitsu?

Niitsu has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 13.6 °C and it receives 1,733 mm of precipitation per year.

What is the hottest day ever recorded in Niitsu?

The hottest day measured in Niitsu between 1940 and 2025 was 23 August 2018, reaching 38.4 °C.

What is the coldest day in Niitsu?

The coldest day measured in Niitsu between 1940 and 2025 was 1 February 1948, at -9.7 °C.

Does it snow in Niitsu?

Yes. Niitsu gets on average 157.1 cm of snow per year and has around 41 frost days.

Has the climate of Niitsu warmed?

Yes: Niitsu warmed by +2.6 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in Niitsu?

The wettest day measured in Niitsu between 1940 and 2025 was 6 August 1976, with 144 mm of rain in 24 hours.

What was the windiest day in Niitsu?

The windiest day measured in Niitsu between 1940 and 2025 was 16 September 1961, with winds reaching 63.4 km/h.

What is the warmest month in Niitsu?

The warmest month in Niitsu is August (26.2 °C on average); the coldest is January (2.4 °C).

How much does it rain in Niitsu?

Niitsu receives on average 1,733 mm of precipitation per year, spread over about 210 rainy days.

Is it sunny in Niitsu?

Niitsu gets on average 8.4 hours of sunshine per day, roughly 3,066 hours per year over 1940-2025.

What is the biggest single-day snowfall in Niitsu?

The heaviest 24-hour snowfall measured in Niitsu between 1940 and 2025 was 15 February 2014, with 21.9 cm.

Are there tropical nights in Niitsu?

Yes: Niitsu has on average 68 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in Niitsu?

In Niitsu, between 1940 and 2025, the highest apparent temperature reached 45.1 °C on 23 August 2023, and the lowest was -14.7 °C on 12 February 1942.

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