Jasik, DominikaSzyga-Pluta, Katarzyna2017-09-252017-09-252015Badania Fizjograficzne, Seria A, Tom 66, 2015, s. 35-452081-6014http://hdl.handle.net/10593/19311This paper presents the daily and annual course of thunderstorms in Kalisz. The research was based on records from the period 1985–2014 from the Institute of Meteorology and Water Management, and more detailed archived meteorological data from the period 2004–2014 from the station in Kalisz. The study identified no clear trend in the number of days with thunderstorms during the study period, except a slight increase of the thunderstorm occurrence frequency. Thunderstorms form during the whole year and all day long. However, the warm part of the year is connected with the highest thunderstorm activity in Kalisz, as well as the warmest part of the day. They appear most frequently between 15.01 and 16.00. The majority of thunderstorms last for only 11–20 minutes. The longest storm was observed on September 17th, 2010 (361 min.). They arrive mainly from the south west.polinfo:eu-repo/semantics/openAccessthunderstormdaily and annual courseKaliszArtykułhttps://doi.org/10.14746/bfg.2015.6.3