Yachi climate — normals and trends
Yachi (Japan) has a hot-summer humid continental climate (Dfa) under the Köppen-Geiger classification. Its mean annual temperature is 10.0 °C and it receives 1,506 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 (23.1 °C on average) and the coldest is January (-1.9 °C). Rainfall peaks in July.
Yachi averages 118 frost days, 10 hot days (≥ 30 °C) and 205 rainy days per year.
Yachi has warmed by +2.7 °C between 1940 and 2025, or +0.32 °C per decade. This trend is statistically significant.
The number of frost days there went from about 138 to 98 per year over the period.
The hottest day of the period reached 36.4 °C (on 23 August 2018) and the coldest -19.6 °C (on 4 December 1950).
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
YachiYamagata
- coords
- 38.42°, 140.31°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.0°C
Average daily high
13.9°C
Average daily low
6.3°C
Annual rainfall
1,506mm
Sunshine / day
8.0h
Mean relative humidity
80%
Average peak wind
13.1km/h
Seasonal range
25.0°C
Frost days (< 0 °C)
118 d/yr
Hot days (≥ 30 °C)
10 d/yr
Rainy days (≥ 1 mm)
205 d/yr
Annual snowfall
264.0 cm
Average feels-like high
12.8 °C
Average feels-like low
4.7 °C
Average peak gust
39.1 km/h
Tropical nights (≥ 20 °C)
29 d/yr
Solar radiation
13.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.7 °C
since 1940
+0.3 °C per decade · r² = 0.67 · p = < 0.001
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
36.4 °C
23 August 2018
Coldest day
-19.6 °C
4 December 1950
Wettest day
136 mm
18 August 2004
Windiest day
44.7 km/h
14 December 2025
Strongest gust
138.6 km/h
27 September 1959
Hottest feels-like
40.5 °C
14 August 2007
Coldest feels-like
-24.1 °C
4 December 1950
Snowiest day
39.8 cm
24 December 1980
Sunniest day
14.4 h
18 June 1987
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?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 2.0 °C | +1.0 °C | 149 mm | +18 mm |
| Feb | 1.7 °C | 0.0 °C | 119 mm | +14 mm |
| Mar | 7.9 °C | +2.5 °C | 90 mm | -22 mm |
| Apr | 13.8 °C | +1.4 °C | 129 mm | +33 mm |
| May | 19.3 °C | +0.8 °C | 149 mm | +53 mm |
| Jun | 25.7 °C | +3.8 °C | 94 mm | -31 mm |
| Jul | 30.9 °C | +5.5 °C | 56 mm | -129 mm |
| Aug | 29.7 °C | +2.6 °C | 259 mm | +113 mm |
| Sep | 25.4 °C | +2.8 °C | 142 mm | -1 mm |
| Oct | 17.4 °C | +0.8 °C | 163 mm | +47 mm |
| Nov | 11.4 °C | +1.1 °C | 120 mm | +8 mm |
| Dec | 5.4 °C | +1.6 °C | 165 mm | +25 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Yachi?
Yachi has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 10.0 °C and it receives 1,506 mm of precipitation per year.
What is the hottest day ever recorded in Yachi?
The hottest day measured in Yachi between 1940 and 2025 was 23 August 2018, reaching 36.4 °C.
What is the coldest day in Yachi?
The coldest day measured in Yachi between 1940 and 2025 was 4 December 1950, at -19.6 °C.
Does it snow in Yachi?
Yes. Yachi gets on average 264.0 cm of snow per year and has around 118 frost days.
Has the climate of Yachi warmed?
Yes: Yachi warmed by +2.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Yachi?
The wettest day measured in Yachi between 1940 and 2025 was 18 August 2004, with 136 mm of rain in 24 hours.
What was the windiest day in Yachi?
The windiest day measured in Yachi between 1940 and 2025 was 14 December 2025, with winds reaching 44.7 km/h.
What is the warmest month in Yachi?
The warmest month in Yachi is August (23.1 °C on average); the coldest is January (-1.9 °C).
How much does it rain in Yachi?
Yachi receives on average 1,506 mm of precipitation per year, spread over about 205 rainy days.
Is it sunny in Yachi?
Yachi gets on average 8.0 hours of sunshine per day, roughly 2,920 hours per year over 1940-2025.
What is the biggest single-day snowfall in Yachi?
The heaviest 24-hour snowfall measured in Yachi between 1940 and 2025 was 24 December 1980, with 39.8 cm.
Are there tropical nights in Yachi?
Yes: Yachi has on average 29 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Yachi?
In Yachi, between 1940 and 2025, the highest apparent temperature reached 40.5 °C on 14 August 2007, and the lowest was -24.1 °C on 4 December 1950.
Compare Yachi with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Yachi