Synopsis A number of cases has been observed in which the presence of high energy electrons of 109 eV is directly recorded during thunderstorms. In one instance on the 3rd of May 1952, a 4 to 6% increase above the mean value of the ionisation was found in 6 different recording instruments. In one vessel shielded by 110 cm Fe no increase was found. Three cases were noticed in 1951, and since the 3rd of May 1952 three more have been detected. No influence was discovered in vessels with 110 cm iron shelding. The energies lie below 1010 eV. An increased ionisation was also found during heavy rainfall.