Great Istanbul is the biggest city in Turkey and most populated European locality. Former capital of four empires lies on both sides of the Bosporus strait. European and Asian parts of the city are situated on hilly coasts of the Sea of Marmara and connected by numerous bridges and tunnels. Istanbul has subtropical climate moderated by cold northern winds.

Seasonal weather transitions are smoothened by the Sea of Marmara and the Black Sea. Summers are usually pretty hot and humid, though actual heat occurs rarely. Winters are cool with plenty of rains and shifty weather conditions. Temperatures below freezing are lasting for 21 day in average. Snow usually falls each year, but there in not much of it.

Seasons

Spring in Istanbul

Comparing to Mediterranean localities spring in Istanbul is cool, but it is very sunny. The city drowns in lush greenery and dotted by flowerbeds with blooming tulips. March is quite cool and rainy. Temperature ranges for first spring month are between 11 °C (52 °F) and 5 °C (41 °F). Also, around 3 days in March are even snowy.

Temperature grows and precipitation reduces with course of the season. Late May is as warm as 20 °C (68 °F) at afternoon and 12 °C (53 °F) at night. Precipitation is less by third comparing to March. Last stage of spring is great time to visit the city for tour around remarkable historic sights of it.

Climate of the Spring Months

March Max average t°: +11 °C (51 °F) Min average t°: +4 °C (39 °F) Water t°: +8 °C (34 °F) Sundial in the day: 7 hours Rainy days: 4 days Precipitation: 46 mm (1.8")

April Max average t°: +16 °C (61 °F) Min average t°: +7.5 °C (46 °F) Water t°: +11 °C (52 °F) Sundial in the day: 9 hours Rainy days: 2 days Precipitation: 33 mm (1.3")

May Max average t°: +21 °C (69 °F) Min average t°: +12 °C (53 °F) Water t°: +16 °C (61 °F) Sundial in the day: 11 hours Rainy days: 2 days Precipitation: 32 mm (1.3")

Spring Holidays

March 18 – Day of the Battle at Çanakkale.
March 21 – Newrouz.

April – Istanbul Film Festival.
April 23 – Children Protection Day.
April 25 – Commemoration of the Anzac Landings.
April-May – Istanbul Tulip Festival.

May 1 – Labor Day.
May 2 – International Istanbul Puppet Festival.
May 19 – Day of youth and sport, Ataturk’s Day.
May 20 – Chill Out Festival.
May 26-31 – Conquest Celebrations.
May-June – International Theatre Festival, Istanbul International Music Festival.

Summer in Istanbul

First days of June bring warm up to 26 °C (79 °F) while daily amount of sunshine hours increases to 10. In July air warms up to 28-30 °C (82-86 °F). Combined with high humidity heat makes air stuffy. In August heat may exceed mentioned marks. Fortunately there are several beaches in Istanbul. They’ll help to wait out the hottest time in the sea with pleasant 19-22 °C (66-71 °F). Hiding in conditioned rooms is equally great idea. At evenings air is more pleasant with temperature of 19-22 °C (66-71 °F).

Despite high relative air humidity rains are actually rare in summer. May is the driest month, so amount of precipitation is gradually growing through a season. Due to seasonal changes of amount of sunlight and partially because of low cloudiness summer is the brightest season in Istanbul.

Climate of the Summer Months

June Max average t°: +25 °C (78 °F) Min average t°: +16 °C (61 °F) Water t°: +21 °C (70 °F) Sundial in the day: 13 hours Rainy days: 2 days Precipitation: 22 mm (0.9")

July Max average t°: +28 °C (82 °F) Min average t°: +19 °C (66 °F) Water t°: +24 °C (75 °F) Sundial in the day: 13.5 hours Rainy days: 1 days Precipitation: 15 mm (0.6")

August Max average t°: +27.5 °C (82 °F) Min average t°: +19 °C (66 °F) Water t°: +24.5 °C (76 °F) Sundial in the day: 12 hours Rainy days: 0~1 days Precipitation: 10 mm (0.4")

Summer Holidays

July – Grease Wrestling.
July 1-16 – Istanbul International Jazz Festival.
July 31 – Istanbul Shopping Festival.

August 30 – Victory Day.

Autumn in Istanbul

In general autumn in Istanbul is warm, though amount and frequency of precipitation grows with progression of the season. September is completely warm with daily range of temperatures between 16 °C (61 °F) and 25 °C (77 °F). Even the sea is warm enough for swimming.

Gradual cooling results drop of daily temperature to range of 12-19 °C (53-66 °F) in October and to 9-14 °C (48-57 °F) in November. The sea cools below comfortable temperature in October and daily amount of sunshine reduces too.

Climate of the Autumn Months

September Max average t°: +24 °C (75 °F) Min average t°: +16 °C (60 °F) Water t°: +23 °C (73 °F) Sundial in the day: 10 hours Rainy days: 3 days Precipitation: 35 mm (1.4")

October Max average t°: +19 °C (67 °F) Min average t°: +12 °C (54 °F) Water t°: +19 °C (66 °F) Sundial in the day: 7 hours Rainy days: 4 days Precipitation: 58 mm (2.3")

November Max average t°: +15 °C (59 °F) Min average t°: +8 °C (47 °F) Water t°: +15 °C (59 °F) Sundial in the day: 6 hours Rainy days: 3 days Precipitation: 54 mm (2.1")

Autumn Holidays

September – Rock ‘n’ Coke Festival.
September-November (odd years) – International Istanbul Biennial.

October – Fotoİstanbul.
October 29 – Day of the Republic.
October-November – Tüyap Book Fair.

November – Efes Pilsen Blues Festival.
November 3-19 – Akbank International Jazz Festival.

Winter in Istanbul

Piercing winds, overcast and rains are main features of winter in Istanbul. On the other hand temperature never drops below freezing. Daytime averages are between 8 °C (46 °F) and 10 °C (50 °F) and at night temperature hovers between 3 °C (37 °F) and 6 °C (43 °F). From time to time air even warm up to 15 °C (59 °F) under rays of bright winter sun.

December is the rainiest month with around 17 days with precipitation. Snow falls occasionally, but accumulates poorly due to winter temperature ranges. There are few tourists, main attractions are open and local culinary is available year round. For quiet and informative tour or gastronomic journey winter is completely suitable.

Climate of the Winter Months

December Max average t°: +11 °C (52 °F) Min average t°: +5 °C (42 °F) Water t°: +11.5 °C (53 °F) Sundial in the day: 5 hours Rainy days: 6 days Precipitation: 80 mm (3.2")

January Max average t°: +8.5 °C (47 °F) Min average t°: +3 °C (37 °F) Water t°: +9 °C (48 °F) Sundial in the day: 4.5 hours Rainy days: 5 days Precipitation: 72 mm (2.95")

February Max average t°: +9 °C (47 °F) Min average t°: +3 °C (37 °F) Water t°: +8 °C (46 °F) Sundial in the day: 5.5 hours Rainy days: 3 days Precipitation: 55 mm (2.2")

Winter Holidays

December – Istanbul Short Film Festival.
December 31 – New Year’s Eve.

January 1 – New Year Celebrations.

Main religious observances and holidays are being held according to Islamic moon calendar, so dates of Ramadan, Kurban Bayrami, Asure Gunu and many other festivities in Gregorian calendar vary from year to year.