Climate and weather
The climate in Białystok is characterized by a fairly cold winter, a cool spring with little precipitation, a moderately
warm summer and a long and rainy autumn. However, some summers have weeks at a stretch of
temperatures around +30°C, and a warm, sunny summer can keep autumn at bay until mid-October.
Poland's long-term and short-term weather patterns are made transitional and variable by the collision of diverse air masses above the country's surface. Maritime air moves across Western Europe, Arctic air sweeps down from the North Atlantic, and subtropical air arrives from the South Atlantic. Although the Arctic air dominates for much of the year, its conjunction with warmer currents generally moderates temperatures and generates considerable precipitation, clouds, and fog. Winter temperatures
may drop to -35°C.
Spring arrives slowly in
April, bringing mainly sunny days after a period of alternating wintry and springlike conditions. Summer, which extends from June to August, is generally less humid than winter. Showers alternate with dry sunny weather that is generated when southern winds prevail. Early autumn is generally sunny and warm before a period of rainy, colder weather in November begins the transition into winter. Winter, which may last one to three months, brings frequent snowstorms but relatively low total precipitation.
The range of mean temperatures is 6°C in the northeast, but individual readings in Poland's regions vary widely by season. Average annual precipitation for the whole country is 600 millimeters.