Sea of Azov - Climate

Climate

The sea is relatively small and practically completely surrounded by land. Therefore, its climate is continental with cold winters and hot and dry summers. In autumn and winter, the weather is affected by the Siberian Anticyclone which brings cold and dry air from Siberia with winds of 4–7 m/s, sometimes up to 15 m/s. Those winds may lower the winter temperatures from the usual −1 to −5°C to below −30°C. The mean mid-summer temperatures are 23–25°C with a maximum of about 40°C. Winds are weaker in summer, typically 3–5 m/s. Precipitation varies between 312 and 528 mm/year and is 1.5–2 times larger in summer than in winter.

Average water temperatures are 0–1°C in winter (2–3°C in the Kerch Strait) and 24–25°C in summer, with a maximum of about 28°C on the open sea and above 30°C near the shores. During the summer, the sea surface is usually slightly warmer than the air. Because of the shallow character of the sea, the temperature usually lowers by only about 1°C with depth, but in cold winters, the difference can reach 5–7°C.

The winds cause frequent storms, with the waves reaching 6 metres in the Taganrog Bay, 2–4 metres near the southern shores, and 1 metre in the Kerch Strait. In the open sea, their height is usually 1–2 metres, sometimes up to 3 metres. Winds also induce frequent seiches – standing waves with an amplitude of 20–50 cm and lasting from minutes to hours. Another consequence of the winds is water currents. The prevailing current is a counter-clockwise swirl due to the westerly and south-westerly winds. Their speed is typically less than 10 cm/s, but can reach 60–70 cm/s for 15–20 m/s winds. In the bays, the flow is largely controlled by the inflow of the rivers and is directed away from the shore. In the Kerch Strait, the flow is normally toward the Black Sea due to the predominance of northern winds and the water inflow from the rivers; its average speed is 10–20 cm/s, reaching 30–40 cm in the narrowest parts. Tides are variable but can peak at 5.5 metres.

The shallowness and low salinity of the sea make it vulnerable to freezing during the winter. Fast ice bands ranging from 7 km in the north to 1.5 km in the south can occur temporarily at any time from late December to mid-March. Under the present climate the sea no longer freezes over, although during the 18th and 19th centuries, and as recently as in the late 1970s, it was normally frozen over every year by early February. The ice thickness reaches 30–40 cm in most parts of the sea and 60–80 cm in the Taganrog Bay. The ice is often unstable and piles up to the height of several metres. Before the introduction of icebreakers, navigation was halted in the winter.