İzmit climate — normals and trends
İzmit (Republic of Türkiye) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 12.4 °C and it receives 954 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 (21.7 °C on average) and the coldest is January (2.9 °C). Rainfall peaks in December.
İzmit averages 45 frost days, 10 hot days (≥ 30 °C) and 137 rainy days per year.
İzmit has warmed by +2.5 °C between 1940 and 2025, or +0.29 °C per decade. This trend is statistically significant.
The number of frost days there went from about 62 to 28 per year over the period.
The hottest day of the period reached 40.2 °C (on 13 July 2000) and the coldest -19.1 °C (on 5 January 1942).
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
İzmitKocaeli
- coords
- 40.76°, 29.93°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
12.4°C
Average daily high
16.9°C
Average daily low
8.6°C
Annual rainfall
954mm
Sunshine / day
9.3h
Mean relative humidity
80%
Average peak wind
11.9km/h
Seasonal range
18.8°C
Frost days (< 0 °C)
45 d/yr
Hot days (≥ 30 °C)
10 d/yr
Rainy days (≥ 1 mm)
137 d/yr
Annual snowfall
98.4 cm
Average feels-like high
16.3 °C
Average feels-like low
7.3 °C
Average peak gust
33.2 km/h
Tropical nights (≥ 20 °C)
7 d/yr
Solar radiation
14.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.5 °C
since 1940
+0.3 °C per decade · r² = 0.60 · 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
40.2 °C
13 July 2000
Coldest day
-19.1 °C
5 January 1942
Wettest day
107 mm
10 September 1981
Windiest day
32.7 km/h
9 October 2003
Strongest gust
101.2 km/h
23 February 1999
Hottest feels-like
43.5 °C
26 July 2023
Coldest feels-like
-24.2 °C
5 January 1942
Snowiest day
37.5 cm
29 December 2016
Sunniest day
14.0 h
27 June 2025
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 | 11.3 °C | +4.9 °C | 83 mm | -21 mm |
| Feb | 6.1 °C | -1.7 °C | 102 mm | +9 mm |
| Mar | 16.6 °C | +5.8 °C | 58 mm | -39 mm |
| Apr | 14.5 °C | -1.4 °C | 73 mm | -9 mm |
| May | 21.3 °C | +1.0 °C | 65 mm | -8 mm |
| Jun | 26.2 °C | +2.0 °C | 11 mm | -60 mm |
| Jul | 30.5 °C | +4.3 °C | 4 mm | -42 mm |
| Aug | 28.7 °C | +2.1 °C | 29 mm | -14 mm |
| Sep | 24.6 °C | +1.3 °C | 50 mm | -10 mm |
| Oct | 19.3 °C | +0.7 °C | 153 mm | +69 mm |
| Nov | 18.1 °C | +4.3 °C | 59 mm | -30 mm |
| Dec | 10.0 °C | +1.3 °C | 112 mm | -2 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 İzmit?
İzmit has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 12.4 °C and it receives 954 mm of precipitation per year.
What is the hottest day ever recorded in İzmit?
The hottest day measured in İzmit between 1940 and 2025 was 13 July 2000, reaching 40.2 °C.
What is the coldest day in İzmit?
The coldest day measured in İzmit between 1940 and 2025 was 5 January 1942, at -19.1 °C.
Does it snow in İzmit?
Yes. İzmit gets on average 98.4 cm of snow per year and has around 45 frost days.
Has the climate of İzmit warmed?
Yes: İzmit warmed by +2.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in İzmit?
The wettest day measured in İzmit between 1940 and 2025 was 10 September 1981, with 107 mm of rain in 24 hours.
What was the windiest day in İzmit?
The windiest day measured in İzmit between 1940 and 2025 was 9 October 2003, with winds reaching 32.7 km/h.
What is the warmest month in İzmit?
The warmest month in İzmit is August (21.7 °C on average); the coldest is January (2.9 °C).
How much does it rain in İzmit?
İzmit receives on average 954 mm of precipitation per year, spread over about 137 rainy days.
Is it sunny in İzmit?
İzmit gets on average 9.3 hours of sunshine per day, roughly 3,395 hours per year over 1940-2025.
What is the biggest single-day snowfall in İzmit?
The heaviest 24-hour snowfall measured in İzmit between 1940 and 2025 was 29 December 2016, with 37.5 cm.
Are there tropical nights in İzmit?
Yes: İzmit has on average 7 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in İzmit?
In İzmit, between 1940 and 2025, the highest apparent temperature reached 43.5 °C on 26 July 2023, and the lowest was -24.2 °C on 5 January 1942.
Compare İzmit with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around İzmit