After days of heavy rains, floods and floods in Istanbul, all eyes are now on the winter season. Rainfall reaching record levels in the city caused the question "What kind of weather awaits Istanbul this winter?" It also brought up the question. So, do the showers in autumn give a sign of snowfall in winter? How effective will the snowfall be in Istanbul this year? Will the white cover cover the city? CNN Türk Meteorology Advisor Prof. Dr. Orhan Şen's prediction for the winter of 2026-2027, made to Milliyet.com.tr, sheds light on frequently asked questions.
IS A SNOW SURPRISE COMING TO ISTANBUL?
Heavy rains and floods in Istanbul in recent days have increased curiosity about how the winter season will pass. After the rainy weather in the city, this time the expectation of snow started to be discussed. CNN TÜRK Meteorology Advisor Prof. Dr. In his evaluation of the 2026-2027 winter, Orhan Şen drew attention to the seasonal snow forecasts prepared for Europe.
ARE THE LATEST RAINS A HERALD OF WINTER?
One of the most curious topics after the heavy rains that continued for days in Istanbul was whether these rains gave any signs of how the next winter would be. Prof. Dr. Orhan Şen stated that the recent rains can be considered as the first signs of the predictions for the winter of 2026-2027. According to Şen, the fact that the predictions that the rains will be more intense and abundant in the region are starting to come true also brings the expectations regarding the winter to the agenda.
According to Şen's assessment, while snowfall in the west of Türkiye is expected to remain below the seasonal average, the increasingly evident heat island effect of the city in Istanbul is among the factors that further reduce the possibility of snow. Şen stated that another scenario predicted for this winter is a milder season and, accordingly, less snowfall.
However, there is no direct and definitive connection between the amount of precipitation in autumn and snowfall in winter. Heavy rains alone do not indicate that the winter will be colder or snowier. The main factors that determine the type of precipitation and whether snow will occur include air temperature, atmospheric circulation and whether cold air systems reach the region.
WHY IS THE POSSIBILITY OF SNOW DECREASING IN ISTANBUL?
As important as the occurrence of snowfall in Istanbul, how effective the rain will be and whether it will hold on the ground is also important. Prof. Dr. One of the prominent elements in Orhan Şen's assessment was the heat island effect, which is becoming increasingly effective in the city.
Dense construction, asphalt and concrete surfaces, and heat resulting from human activities can cause urban centers to remain warmer than their surroundings. This can make it difficult to keep snow on the ground, especially in systems where temperatures hover around zero degrees.
Şen pointed out that the heat island effect in Istanbul is becoming more evident every year and stated that the possibility of snowfall this winter has decreased.
However, the presence of a heat island effect in the city does not mean that there will be no snow in Istanbul. Snow can be seen in Istanbul when sufficiently cold weather and appropriate humidity and precipitation conditions occur at the same time. Whether the snow is effective throughout the city and stays on the ground varies depending on the duration, intensity of the precipitation and the condition of the ground, as well as the temperature.
WHAT DOES THE SNOW MAP OF EUROPE SAY?
Seasonal snowfall forecasts prepared for Europe also stand out in evaluations of the 2026-2027 winter. Prof. Dr. According to the forecast map cited by Orhan Şen, snowfall expectations across Europe do not seem strong. Although the outlook has improved somewhat with the September update, snowfall is expected to remain below normal in the extreme north, northwest and south-southwest parts of Europe. Snowfall above the seasonal average is predicted in the central parts of the continent.
When evaluated from the perspective of Türkiye, the estimates given by Şen indicate that snowfall in the western regions may decrease by 10 to 20 percent compared to the average.
Snowfall is expected to be higher in the Eastern Black Sea and northern Eastern Anatolia, especially at altitudes of 2 thousand to 3 thousand meters, due to low temperatures. It is predicted that the snow cover thickness may be 10-15 centimeters lower in other parts of Anatolia.
"THIS WINTER SNOW EXPECTATION FOR THE MARMARA REGION HAS WEAKENED"
Reminding that snowfall has decreased in the western regions in recent years, Şen evaluated that the snow expectation for the Marmara Region this winter has weakened.
There is an important detail here: Seasonal forecasts show the general trend of a certain period. It does not reveal exactly which day it will snow in Istanbul, how many centimeters of snow it will be, or which districts it will hold on the ground, months in advance.
HOW CAN SUPER EL NINO AFFECT PERSON?
One of the prominent headlines in global meteorological evaluations for the coming winter is El Nino. This climate event, which is associated with above-normal sea surface temperatures in the tropical parts of the Pacific Ocean, can affect atmospheric circulation and jet streams.
Prof. Dr. According to Orhan Şen's assessment, the developing strong El Niño event is expected to change the Pacific jet stream and the routes followed by winter storms. In Europe, the effect of temperate western air currents coming from the Atlantic and high pressure systems extending from the south can create a picture that reduces snowfall in some regions.
However, the effects of El Nino are not seen in the same way in every region of the world. Winter conditions in Europe and Türkiye cannot be explained solely by sea surface temperatures in the Pacific. The pressure pattern in the North Atlantic, polar air movements and regional atmospheric systems are also decisive.
The US National Oceanic and Atmospheric Administration's (NOAA) assessment dated October 8, 2026 also reports that strong to very strong El Nino conditions are expected to last until the first months of 2027. The institution also emphasizes that a strong El Niño does not guarantee the expected regional effects. For this reason, the global development in question cannot be considered as a definitive prediction for Istanbul's winter on its own.
WILL IT KEEP IT ON THE GROUND IF IT SNOWS IN ISTANBUL?
When discussing snow expectations in Istanbul, two different situations need to be distinguished: The occurrence of snowfall and the retention of snow on the ground. Even if the air temperature is close to zero degrees, snowfall can occur under some conditions. However, in order for precipitation to accumulate on the ground, the surface temperature, intensity and duration of precipitation must be appropriate. The heat island effect in urban centers can make accumulation difficult, especially during short-term snowfalls.
On the other hand, the meeting of a strong cold wave coming from the north or northeast with the humid air carried over the Black Sea can create suitable conditions for more effective snowfall in Istanbul. In such systems, if the air temperature drops sufficiently and the precipitation continues for a while, the possibility of snow retention on the ground may increase.
Therefore, the fact that snow expectations are low in seasonal forecasts does not mean that there will be no effective snowfall during the winter. A short-term but strong cold wave in Istanbul can create a picture different from the general trend of the season.
RISK WARNING FOR DAMS ALSO
The decrease in snowfall in winter is important not only in terms of transportation and daily life, but also in terms of water resources. Prof. Dr. Orhan Şen drew attention to the risk of decreasing water levels in the next spring and summer in dams and lakes, especially in Central Anatolia, which are fed by snowmelt. According to Şen's assessment, the Marmara Region is among the regions where this risk should be monitored.
Snow cover can ensure that water accumulated, especially in higher elevations, is stored for a longer period of time and melts in the spring to reach streams and dams. Decreasing snowfall can reduce this contribution. However, not only snowfall determines the future occupancy rates of dams; Total precipitation, evaporation, basin conditions and water consumption are also decisive.
For this reason, in terms of water resources in Istanbul and Marmara, both the amount of rain and snow and the water inflows in the dam basins need to be monitored together during the winter.
WILL ISTANBUL BE CLOTHED IN WHITE THIS WINTER?
Prof. Dr. Orhan Şen's evaluations indicate that snowfall in western Türkiye and the Marmara Region may remain below the seasonal average in the winter of 2026-2027. The urban heat island effect in Istanbul stands out as one of the factors that can make it difficult for snow to stay on the ground. However, Istanbul's winter chart is not finalized yet. Heavy rains in autumn do not necessarily indicate that the winter will be colder or snowier, and the low probability of snow in seasonal forecasts does not mean that Istanbul will not see snow.
The main developments that will determine when and to what extent snow will be effective in Istanbul will be the atmospheric systems that will occur during the winter months and especially the timing of cold waves.
Figure 1. Shows the difference of the snowfall forecast from the average in the months of 2026/2027 Winter December, January and February.
