Impacts of potential climate change on damaging frost during growing season of vegetable crops in Elbe River Lowland (Polabí)

The Elbe River Lowland has experienced a decrease in the number of frost days, while the length of the frost-free period between the last spring frost and the first fall frost has increased. A longer frost-free period can be particularly beneficial for thermophile vegetables (e.g., tomato, eggplant, pepper and melon) in lowlands. The daily minimum air temperature from 116 grid points throughout the studied area for the current (1961-2000) and two future climates under A1B SRES scenario (2021-2050 and 2071-2100) was used. As a result, for the current climate (1961-2000), the dates of the last spring frost have advanced by 2-day per decade on average. The respective fall dates are delayed up to 1.8 days per 10 years, whereas the frost-free period is lengthening by up to 3.7 days per 10 years on average. The average and earliest the first mild fall frosts in 1961−2000 were October 19 and September 26, respectively. The last mild spring frost occurred most frequently between April 23 and May 13 in the current climate. The average the length of frost-free period was 178 days. Under projected future climates, for the entire study region dominant dates of the last spring frost significantly advanced (i.e., occurred earlier) compared to the current climate. The first fall frost will be significantly delayed (i.e., occurred later) under the climate change scenario compared to the current climate (1961-2000).