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Description of climate in a specific location requires describing its main components. The most important components of any climate are average air temperature and total precipitation volume. Of lesser importance are winds, cloudiness, atmospheric pressure, air humidity, occurrence of storms, mists or other weather phenomena. How to characterise the Polish climate, taking all these factors into account?

Average air temperatures in Poland

Average air temperatures are primarily affected by latitude – it affects falling angle of sun rays reaching the Earth’s surface, and therefore general amount of heat. Distance from the sea or the ocean is also very important. Humid marine air accumulates heat slower in comparison to dry inland air. Their temperature is also affected by the surface. Water heats up slower than land, and also loses heat slower. Therefore, at the sea, it is cooler in summer and warmer in winter, in comparison to inland area. Another factor affecting air temperature is absolute altitude. Temperature drops, on average, by 0.6° per 100 m – this is the reason it is usually colder in the mountains than in the lowlands.

On a map, air temperatures are presented by isothermsisothermisotherms. They are lines connecting points with identical temperature values. Additionally, for better comprehension, area between isotherms are filled with colours – “warmer” or “colder”.

The following infographic contains information about the vegetative season of plants in Poland.

Total annual precipitation

Humid masses of marine polar air from above the Atlantic Ocean, oncoming from the west, bear essential influence on the amount and intensity of precipitation. They bring significant amounts of steam which condenses or freezes and falls to Earth in the form of rain or snow. In area of Poland, one can notice a dependency of amount of precipitation on local land morphology. The largest volumes of precipitation are recorded over higher terrains – in the mountains, on highlands and the lakelands. Over such areas, air motion may be prevented by hills, being natural obstacles. The lowest volumes, however, occur on flat lands in central Poland, particularly in Kuyavia and Greater Poland. These regions lie in so‑called “precipitation shadow” of the lakelands.

Both the map and the climatic charts display clearly increased precipitation over mountain areas. High terrain obstacles, such as the mountains, not only prevent humid air masses from the movement, but also favour emergence of convection currents. Within this currents, air which heated up at the ground level rises high and suddenly cools down which leads to condensation of steam.

Looking at climatic charts, one also needs to pay attention to annual precipitation distribution in Poland. It is more or less the same all over the country, i.e. summer precipitation is prevalent.

Winds in Poland

Air temperature difference triggers pressure difference which, in turn, causes air motion – wind.

Apart from winds originating from major barycentres, local winds appear in Poland as well. One of them is , locally called “halny”. It is formed as a result of pressure difference between two sides of a mountain ridge. Mostly, it occurs in the high mountains – the Tatra Mountains or Karkonosze. From the side where the pressure is higher, the air climbs on the slopes (lifts). Next, this air mass rises up and cools down, forming dense cumulus clouds out of condensed steam. Rain falls down, drying up air. Such dry air flows over the mountain chain to the other side where it “slips down” and warms up. Usually, the pressure difference is high which means that warm and dry halny may reach huge speed (often > 100 km/h) and therefore is able to inflict serious damage.

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Schemat ilustruje powstawanie wiatru halnego, halny wind. Po lewej stronie szczytu górskiego, strzałką skierowaną do góry oznaczono wysoką temperaturę powietrza, a po prawej stronie szczytu strzałka skierowaną w dół oznaczono niską temperaturę.Kolejną strzałką oznaczono kierunek wznoszenia się powierza od podnóża szczytu po lewej stronie, w górę szczytu i w dół szczytu po jego prawej stronie. Powietrze po lewej stronie szczytu unosi się do góry i ochładza o minus 0,6 stopni C na każde 100 m wysokości szczytu. U podnóża szczytu na wysokości 800 m jest temp. 4 stopnie C, na wysokości 2500 m, jest temperatura minus 6,2 stopni C. Powietrze ochładzając się powoduje kondensacje pary wodnej i powstawanie chmur, z których pada deszcz niżej lub śnieg wyżej szczytu. Po prawej stronie szczytu powietrze oznaczone fioletową strzałką opad w dół, jako ciepły, suchy i silny wiatr halny. Pogoda jest słoneczna.

Another local wind is breezebreezebreeze, occurring at the sea. Breezes are formed as a result of the difference of air pressure between land area and water area. Humid air over water changes its temperature more slowly than dry air over land. Therefore, during daylight hours it is warmer over land, and warmed up air rises up, leaving lower pressure below which attracts air from above water. This is a sea breeze (onshore breeze). At night, conditions reverse – it is warmer over water because air above this area cools down more slowly; lower air pressure is formed, attracting air from above land. This is a land breeze (offshore breeze).

Exercise 2

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Przypomnij sobie tytuł abstraktu, wysłuchaj nagrania i spróbuj zaproponować własny temat dla dzisiejszej lekcji.

Przypomnij sobie tytuł abstraktu, wysłuchaj nagrania i spróbuj zaproponować własny temat dla dzisiejszej lekcji.

What kind of wind is specific for the area visible in the picture?

• Land breeze (offshore breeze)
• Sea breeze (onshore breeze)
• Halny
• Bora

Exercise 3

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Omów, jak powstaje bryza dzienna.

Omów, jak powstaje bryza dzienna.

Choose the correct type of wind occurring in a specific region of Poland.

• Sea breeze (onshore breeze)
• Land breeze (offshore breeze)
• Foehn
• Sirocco

Keywords

isotherms, wind, climate

Glossary