Climate

The Climate annually in Poland. during the winter season, temperatures would fall below zero degrees during the evening. In the summer, temperatures can reach up to mid 70s to low 80s in Fahrenheit.
There is mostly rain during the months of July to August. it can go up to more than  four inches in a month.
 

Poland's weather can vary during the months. It's temperate climates can be seen as cold winters and warm summers, and part of it is because of the oceanic air currents coming from the west, cold polar air from Scandinavia and Russia, as well as warmer, sub-tropical air from the south.

During the winter, temperatures can fall below zero, with some heavy snowfall. During the late summer and early autumn season, the areas has warm weather because of the influence of dry, sub-tropical, continental air mass.  The average air temperatures amount to 6 - 8.5°C (approx. 43-47°F) for a year, the annual rainfall is 500 - 700 mm (Approx. 20-28 in.), of which snow constitutes only 5 - 20%.

Soldiers return to duty at the tomb of unknown soldier during heavy snow falls in Warsaw, Poland, on Wednesday, Jan. 6, 2010. Poland has recently seen a bout of winter weather with temperatures as low as minus 15 degrees Celius (5 Fahrenheit) . (AP Photo/Czarek Sokolowski)

The Most amount of sunshine during the summer is in the Baltic Coast, while in the winter, Carpathian Mountains.

Required clothing:Lightweights in summer months, with a sweater for walking and the cooler evenings. Medium- to heavyweights are advised in winter. Waterproofing is neccesary throughout the year.

Reference:
http://www.weatheronline.co.uk/reports/climate/Poland.htmhttp://newshopper.sulekha.com/poland-weather_photo_1112188.htm