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Poland Climate
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. When the
moderating
influences are lacking, winter temperatures in mountain
valleys
may drop to -40° 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
to 8° C
in the southwest, but individual readings in Poland's
regions
vary widely by season. On the highest mountain peaks, the
mean
temperature is below 0° C. The Baltic coast, influenced by
moderating west winds, has cooler summers and warmer
winters. The
other temperature extreme is in the southeast along the
border
with Ukraine, where the greatest seasonal differences
occur and
winter temperatures average 4.5° C below those in western
Poland.
The growing season is about forty days longer in the
southwest
than in the northeast, where spring arrives latest.
Average annual precipitation for the whole country is
600
millimeters, but isolated mountain locations receive as
much as
1,300 millimeters per year. The total is slightly higher
in the
southern uplands than in the central plains. A few areas,
notably
along the Vistula between Warsaw and the Baltic and in the
far
northwest, average less than 500 millimeters. In winter
about
half the precipitation in the lowlands and the entire
amount in
the mountains falls as snow. On the average, precipitation
in
summer is twice that in winter, providing a dependable
supply of
water for crops.
Data as of October 1992
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