Iki climate — normals and trends
Iki (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 17.0 °C and it receives 1,647 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 (26.8 °C on average) and the coldest is January (8.2 °C). Rainfall peaks in June.
Iki averages 0 frost days, 1 hot days (≥ 30 °C) and 137 rainy days per year.
Iki has warmed by +1.1 °C between 1940 and 2025, or +0.13 °C per decade. This trend is statistically significant.
The hottest day of the period reached 31.6 °C (on 10 August 1994) and the coldest -2.2 °C (on 26 February 1981).
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
IkiNagasaki
- coords
- 33.78°, 129.72°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
17.0°C
Average daily high
18.1°C
Average daily low
16.1°C
Annual rainfall
1,647mm
Sunshine / day
8.4h
Mean relative humidity
74%
Average peak wind
32.0km/h
Seasonal range
18.6°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
137 d/yr
Annual snowfall
4.0 cm
Average feels-like high
17.1 °C
Average feels-like low
13.2 °C
Average peak gust
45.0 km/h
Tropical nights (≥ 20 °C)
124 d/yr
Solar radiation
14.6 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.1 °C
since 1940
+0.1 °C per decade · r² = 0.34 · 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
31.6 °C
10 August 1994
Coldest day
-2.2 °C
26 February 1981
Wettest day
242 mm
17 August 1949
Windiest day
101.9 km/h
31 August 1987
Strongest gust
190.8 km/h
31 August 1987
Hottest feels-like
39.8 °C
5 August 2010
Coldest feels-like
-13.8 °C
26 February 1981
Snowiest day
7.4 cm
24 January 2016
Sunniest day
13.8 h
20 June 1948
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 | 10.0 °C | +0.2 °C | 37 mm | -41 mm |
| Feb | 8.6 °C | -1.4 °C | 64 mm | -21 mm |
| Mar | 12.5 °C | +0.2 °C | 146 mm | +31 mm |
| Apr | 15.8 °C | +0.2 °C | 68 mm | -74 mm |
| May | 18.6 °C | -0.1 °C | 181 mm | +31 mm |
| Jun | 22.7 °C | +1.1 °C | 277 mm | +29 mm |
| Jul | 27.5 °C | +1.9 °C | 86 mm | -146 mm |
| Aug | 29.1 °C | +1.6 °C | 263 mm | +110 mm |
| Sep | 27.9 °C | +2.8 °C | 201 mm | +21 mm |
| Oct | 23.5 °C | +2.4 °C | 65 mm | -33 mm |
| Nov | 18.2 °C | +1.2 °C | 44 mm | -50 mm |
| Dec | 14.5 °C | +2.2 °C | 78 mm | +4 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 Iki?
Iki has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 17.0 °C and it receives 1,647 mm of precipitation per year.
What is the hottest day ever recorded in Iki?
The hottest day measured in Iki between 1940 and 2025 was 10 August 1994, reaching 31.6 °C.
What is the coldest day in Iki?
The coldest day measured in Iki between 1940 and 2025 was 26 February 1981, at -2.2 °C.
Does it snow in Iki?
Yes. Iki gets on average 4.0 cm of snow per year and has around 0 frost days.
Has the climate of Iki warmed?
Yes: Iki warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Iki?
The wettest day measured in Iki between 1940 and 2025 was 17 August 1949, with 242 mm of rain in 24 hours.
What was the windiest day in Iki?
The windiest day measured in Iki between 1940 and 2025 was 31 August 1987, with winds reaching 101.9 km/h.
What is the warmest month in Iki?
The warmest month in Iki is August (26.8 °C on average); the coldest is January (8.2 °C).
How much does it rain in Iki?
Iki receives on average 1,647 mm of precipitation per year, spread over about 137 rainy days.
Is it sunny in Iki?
Iki 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 Iki?
The heaviest 24-hour snowfall measured in Iki between 1940 and 2025 was 24 January 2016, with 7.4 cm.
Are there tropical nights in Iki?
Yes: Iki has on average 124 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Iki?
In Iki, between 1940 and 2025, the highest apparent temperature reached 39.8 °C on 5 August 2010, and the lowest was -13.8 °C on 26 February 1981.
Compare Iki with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Iki