Yalta is sheltered from the cold winds by a semicircle of mountains: from the east by a spur of Mt. Avinda ( 1473 m. ), from the west - by the cone-shaped Mt. Mogabi ( 804 m. ). Dominating inside this hollow hemmed in by the mountains and exposed to the sea are local winds - breezes that ventilate the air basin over Yalta. The change of breezes occurs usually at about 7 a.m. and 9 p.m. The sea breezes bring to the town the air charged with the sea water salts, those blowing from the mountains carry along phylon-cides of the pine forests. The breezes gain utmost force in August.
The sea plays an essential part in forming the South Coast's climate. Its water which accumulates warmth during summer is slow to deliver it in the first half of winter and off Yalta where the zone of great depths is quite close to the shore the sea retains its warmth longer than in shallow areas. That is why there is no change of seasons usual in the Central Belt of the Ukraine. In fact the year on the Southern Coast of the Crimea divides into two well-defined periods - the warm (from May till October) and the cold one (from November till April). The well- known physician and climatolegist Vladimir Dmitriyev wrote about winter in Yalta: "To be more precise and rank with the winter days all those when average daily temperature drops below freezing point it should be said that winter by northern standards lasts on the South Coast only 10 days".
The temperature of the sea water begins to rise in April and reaches towards the beginning of June +18 °C when actually the bathing season starts. Its average duration is 126 days.
|Mean day's temperature in Yalta ( °С )
The mean annual temperature of the air in Yalta according to the long-term observations is +13.1°C (by way of comparison - in Simferopol +9.8°C, in Moscow +3.6°C). The average temperature of the air in July +24°C (approximately the same as on the French and Italian Riviera: +22 - +24°C), in January +3.8°C (on the Riviera around +7°C).
As far as the number of hours of sunshine is concerned Yalta is also on a par with the celebrated resorts of the Mediterranean - Nice, Antibes, Bordighera, Rapallo, Cannes, Menton, San Remo, Portofino. On average Yalta has a share of 2,250 hours of sunshine a year.
The relative humidity of the air on the South Coast of the Crimea is less than anywhere else on the territory of the Ukraine. The precipitation on the average is about 700 mm a year (on the Riviera from 500 to 750mm).
Such a rare combination of natural factors - the warm sea, the pine-clad mountains, the abundance of sunshine, the dryness of the air and the luxuriant southern vegetation make the climate of the South Coast's central part and first and foremost that of Yalta the only one of its kind.