Beginning of winter and the weather

But this is just astronomically. We know very well that the real winter with snow and frost comes at different times. Nature has its own calendar and this calendar "year to year do not have to." It is easy to see that the timing of annual seasons are changing every year. In the same place in the spring starts before then, sometime later. The same can be said about the winter and other seasons. Precipitation, number of clear and cloudy days, the prevalence of high or low temperatures - all in different years is subject to major fluctuations for each season and month. To monitor these variations, to be able to understand them - not an empty fun. It is necessary for the farmer and gardener and hunter. Fishing, hunting fishing, agricultural and forestry works, large and small animal husbandry, poultry farming, pisciculture, sericulture, bee-keeping - all of it largely is dependent on the climate and location, from the constant weather changes. By what signs we can confidently say that there was a real winter? The first frost - it is not winter: they are often long before it started. Frosts are replaced with heat, the snow falls and melts away several times. That's when settles lasting snow cover and freezing water - that's another matter. However, different bodies of water freeze is not in the same time. Pond freezes, rather than a river. Fast flow can not freeze all winter. Large lake freezes slower small. On the surface waves are walking for a long time after the lake shores were white with snow, and the neighboring ponds covered with ice. Freezing water is usually under steady temperature falls below 0 °. At this time the soil surface freezes well, so that stopped her fall treatment. Thus, ice on the ponds, we can take for the beginning of winter. End of winter comes with the advent of thaw holes. Dark spots appear naked before all the land on the slopes facing south. Later, they begin to dapple smooth space open fields. On the northern slopes, near the northern opushek and especially in the forest snow keeps much longer. Almost at the same time, the first migrant birds arrive - rooks (the average term for suburban locations falls on March 19). Not for nothing Kaigorodov would take for the end of winter to the middle band is arriving rooks. This feature is only good for the middle band. North of Leningrad rook little nests. It does not happen in many places in the northern half of the forest zone in the north. And in the warmer parts of the country he did not fly away for the winter. Therefore, a more reliable indication of the end of winter, suitable for large area, we should recognize the emergence of thaw holes.