The climate of the Korosten district is moderately continental. The main factors affecting the formation of the climate of this territory are solar radiation, circulation of air masses, partial forest cover and wetlands.
Korostenshchyna lies in the temperate light zone of the northern hemisphere. Therefore, the angle of incidence of the sun’s rays on the days of the spring and autumn equinoxes is approximately 34°, the maximum on June 22 is 57°, and the minimum on December 22 is about 11°. Total solar radiation is close to 95 kcal per 1 square meter.
The average annual air temperature is approximately +6°.
Average temperatures by month: January -6°, February -5°, March 0°, April +7°, May +13°, June +16°, July +19°, August +17°, September +12°, October +6°, November +1°, December –3°.
The frost-free period lasts about 170 days a year, with a temperature above 0° – about 245 days, with a temperature above +10° – about 105 days. The maximum temperature over the last century was +37°, and the minimum was -34°. Spring frosts are sometimes observed even at the end of May – beginning of June, and autumn frosts can already occur from mid-September.
The average annual amount of precipitation is 500-600 mm, the most falls in the summer months – about 240 mm, the least in the winter – about 80 mm. A stable snow cover is formed no earlier than mid-December, and melts in mid-March. The height of the snow cover in recent years rarely exceeds 25 cm.
Northwest, west, and north winds prevail in the region. Wind speed rarely exceeds 15-20 m/s. The number of days with atmospheric drought and dry spells varies from year to year, from 3 to 40 days per year.
The relative humidity of the air during the year fluctuates no more than 70-95%, and the average annual humidity is about 85%. The number of cloudless days during the year is about 80-85, the most in July-August, the least in November-December.
The transition from one season to another happens gradually. The beginning of winter falls on the second half of November. Winter is mild, with frequent thaws, ascent and re-formation of snow cover. Only some winters are quite severe. For example, during the last twenty years, such were the winters of 1980, 1987, 1996, 2006. In those years, the air temperature dropped below -30°. The main causes of unstable weather in winter are the alternating influence of Atlantic cyclones and Arctic air masses, and sometimes continental Asian cyclones.
Spring comes at the end of March, when the temperature begins to rise very intensively, twice as much as in winter, and the amount of precipitation increases. But the air temperature until the end of May is very unstable, there are often frosts both on the surface of the soil and in the air.
Summer begins at the end of May, when the average daily temperature stabilizes at no more than +15° and then increases slowly, and gradually begins to decrease in August. During this period, there are frequent thunderstorms with showers, and sometimes hail. Some years are characterized by summer droughts. So, for example, from July 10 to the end of August 1992, only about 25 mm of rain fell, the daytime temperature remained stable at +30 °, and on some days it rose to +35 °. The same was true in the summer of 2007. In contrast, the summer months are sometimes too wet. So, in June 1980 and in July 1993, six months’ worth of precipitation fell.
Autumn comes in September, the first half is still quite warm, but there is a constant decrease in temperature. At the beginning of autumn, the amount of precipitation is insignificant, and in the second half there is a gloomy period with frequent prolonged rains due to the strengthening of cyclonic activity. From the middle of November, precipitation begins to fall in the form of wet snow.