Maribor/Slovenska Bistrica has a humid continental climate (Köppen climate classification: Dfb), bordering on oceanic climate (Köppen: Cfb). Average temperatures hover around zero degrees Celsius during the winter. Summers are generally warm. Average temperatures during the city’s warmest month (July) exceed 20 degrees Celsius, which is one of the main reasons for the Maribor/Slovenska Bistrica wine tradition. The city sees on average roughly 900 mm (35.4 in) of precipitation annually and it’s one of the sunniest Slovene cities, with an average of 266 sunny days throughout the course of the year. The most recent temperature heatwave record for August is 40.6 °C, measured at the Maribor–Tabor weather station by the Slovenian Environment Agency (ARSO) on 8 August 2013.