the Köppen climate classification, Wrocław has an oceanic climate (Cfb), bordering on a humid continental climate (Dfb) using the 0 °C (32 °F) isotherm. The position of Wrocław in the Silesian Lowlands, which are themselves located just north of the Sudetes and to the southwest of the Trzebnickie Hills, creates a favourable environment for accumulation of heat in the Oder river valley between Wrocław and Opole. Wrocław is therefore the warmest city in Poland, among those tracked by the Institute of Meteorology and Water Management (IMGW), with the mean annual temperature of . The city experiences relatively mild and dry winters, but with the skies frequently overcast; summers are warm and generally sunny, however, that is the period when most precipitation occurs, which often falls during thunderstorms. The city also sometimes experiences foehn-like conditions, particularly when the wind blows from the south or the south-west. In addition to that, the temperatures in the city centre often tend to be higher than on the outskirts due to the urban heat island effect. Snow may fall in any month from October to May but normally does so in winter; the snow cover of at least stays on the ground for an average of 27.5 days per year – one of the lowest in Poland. The highest temperature in Wrocław recognised by IMGW was noted on 8 August 2015 (), though thermometers at the meteorological station managed by the University of Wrocław indicated on that day. The lowest temperature was recorded on 11 February 1956 (). Government and politics Wrocław is the capital city of Lower Silesian Voivodeship, a province (voivodeship) created in 1999. It was previously the capital of Wrocław Voivodeship. The city is a separate urban gmina and city-county. It is also the seat of Wrocław County, which adjoins but does not include the city. Districts Wrocław was previously subdivided into five boroughs (dzielnica): Fabryczna ("Factory Quarter") Krzyki, (, meaning "Wranglers") Psie Pole (, "Dogs' Field", named after the Battle of Psie Pole) Stare Miasto (Old Town) Śródmieście (Midtown) Since 1990, the city has been divided into 48 district quarters (osiedle) – Bieńkowice, Biskupin-Sępolno-Dąbie-Bartoszowice, Borek, Brochów, Gaj, Gajowice, Gądów-Popowice Płd., Grabiszyn-Grabiszynek, Huby, Jagodno, Jerzmanowo-Jarnołtów-Strachowice-Osiniec, Karłowice-Różanka, Klecina, Kleczków, Kowale, Krzyki-Partynice, Księże, Kuźniki, Leśnica, Lipa Piotrowska, Maślice, Muchobór Mały, Muchobór Wielki, Nadodrze, Nowy Dwór, Ołbin, Ołtaszyn, Oporów, Osobowice-Rędzin, Pawłowice, Pilczyce-Kozanów-Popowice Płn., Plac Grunwaldzki, Polanowice-Poświętne-Ligota, Powstańców Śląskich, Pracze Odrzańskie, Przedmieście Oławskie, Przedmieście Świdnickie, Psie