City by Month

Istanbul in January

In January, Istanbul has 86.3 mm (3.40 in) of rain, a daily high of 9.3 °C (48.7 °F) and a daily low of 3.9 °C (39.0 °F), as 1991-2020 model estimates; figures in brackets are converted. The daily high is a model estimate, adjusted against station records.

Last updated : back, with ERA5-Land model estimates.

Best time to visit Istanbul: January misses our rule: days are 6.7 °C under our 16 °C and nights are 4.1 °C under our 8 °C (model estimates). Expect 10.9 rain days (model estimate) and days that grow by 47 min.

What January is like in Istanbul

How we choose these portraits

Key figures

Weather in January, 1991-2020 model estimates

Daily high
9.3 °C (48.7 °F)
Daily low
3.9 °C (39.0 °F)
Rain
86.3 mm (3.40 in) in the month
Sunshine
no data

Model estimate 1991-2020, not a weather station: ERA5-Land model estimates (Copernicus), computed by City by Month for the grid cell nearest the city. Daily high and Days with rain: model estimate, adjusted against station records. Licence: CC BY 4.0. Checked . How we make and test model estimates

Model estimate for the ERA5-Land grid cell at 41.0° N, 29.0° E, 4 km from the city centre point.

How we define and convert these figures

Notes. Sunshine: Not in our ERA5-Land estimates.

Daylight on 15 January 2026

Sunrise
08:27 local time
Sunset
18:00 local time
Day length
9 h 33 min

Day length 1-31 January: 9 h 17 min to 10 h 04 min, +47 min.

How we compute daylight

Source: NOAA Solar Calculator equations, checked .

Month by month

Each month: daily high in °C, then rain in mm, 1991-2020 model estimates.

ERA5-Land model estimates 1991-2020, as above, checked .

This month against the year

Istanbul: January ranked against the 12 months
MeasureJanuaryRank
Daily high9.3 °Ccoldest
Daily low3.9 °C2nd coldest
Rain86.3 mm2nd wettest
Sunshineno datano data
Day length9 h 33 min2nd shortest

Equal values share a rank. How we rank months

Istanbul in January, on average: 10.9 rain days (1 mm or more). Model estimate, adjusted against station records.

ERA5-Land model estimates 1991-2020, as above, checked .

Day length: NOAA solar equations, checked .

Public holidays this month

Istanbul: public holidays in January 2026
DateHoliday
ThursdayNew Year's Day
Istanbul: public holidays in January 2027
DateHoliday
FridayNew Year's Day

Typed from the official lists for 2026 and 2027 and re-checked, .

English names are from the holidays library where the official list gives none. How we check holidays

Source: Official public holiday list (vakithesaplama.diyanet.gov.tr) for 2026 and 2027, checked ; holidays Python library, checked . Library: holidays 0.105.

Same month in 8 model-estimate cities

Istanbul is the coolest of our 8 model-estimate cities in January by mean daily high. How we rank cities

Closest high and low in January: Porto (3.7 °C apart), Lisbon (5.6), Delhi (7.8).

January in 8 model-estimate cities: daily high and low, monthly rain, 1991-2020 model estimates. Bars: high and low share one scale, coldest to warmest city; rain starts at zero.
CityGap from Istanbul, °CHigh, °CLow, °CRain, mmSunshine, hours
Istanbul (this page)—9.33.986.3no data
Porto (closest)3.714.16.4133.3no data
Lisbon (closest)5.614.99.566.5no data
Delhi (closest)7.821.07.8no datano data
Melbourne14.126.614.852.5no data
Sydney16.927.119.976.1no data
Mumbai18.130.419.0no datano data
Bangkok20.431.922.1no datano data

Sources (1991-2020): ERA5-Land model estimates, checked . Each city's page names its grid cell. All sources in full on Methodology.

All cities in January

Sources

Official sources

Cite this page: City by Month. "Istanbul in January: weather, daylight, holidays". https://citybymonth.com/cities/turkey/istanbul/january/. Last updated 8 November 2026.