The highest day temperature in December 2025 was 65°F. The lowest night temperature was 30°F. The average values for day and night temperatures during December were 51.5°F и 42.8°F respectivly.

The average sea surface temperature in December 2025 for Izmit was 56.8°F. The maximum and minimum values were 54.0°F and 59.8°F respectively.

You can expect various weather conditions during December. Be ready for sunny, cloudy or even gloomy days.

Precipitation total in December for Izmit is 3.3 in. It makes december the most rainy month of the year.

The average wind speed in December is 5.3 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Izmit in December is 4.8 hours.