May – Institute of Atmospheric Physics CAS

01/05/1958 The start of regular vertical ionospheric sounding at the Průhonice observatory

08/05/1998 Communication with the MAGION 5 satellite recovered after a break of almost a year and a half

11/05/1878 * Stanislav Hanzlík, author of works on the vertical stucture of pressure systems (+ 8 October 1956)

12/05/2010 Czech Republic became a full member of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT)

18/05/1850 * Oliver Heaviside, who predicted the existence of the ionospheric E layer (+ 3 February 1925)

23/05/1917 * Edward N. Lorenz, author of the theory of deterministic chaos (+ 16 April 2008)

26/05/1826 * Richard C. Carrington, who observed solar differential rotation (+ 27 November 1875)

28/05/1879 * Milutin Milanković, author of the theory of the influence of orbital variations on the Earth's climate (+ 12 December 1958)