The heatwave is now almost all central and east Europe. The Institute of Meteorology and Water Management implemented in all provinces in Poland (the second stage of risk - regarding heat).
Unfortunately, such a high temperature causes local storms, which can be very dangerous. Temperature fluctuations mean that onions often do not know how to "behave", that's why flower balls started to form. Temperature is one of the reasons for their formation.
Below is a comparison of the same period in 2018 and 2019. We see that the lower temperatures reach lower in 2019 than 2018.