Abstract <p>The Sun's significant effect on climate is its indirect effect on the flux of galactic cosmic rays (CR) into the atmosphere. This study examines the specific changes in the CR intensity (specifically its decrease - Forbush decrease) and solar and geomagnetic parameters during the formation and intensification of hurricanes over the North Atlantic Ocean. Thirteen non-overlapping strong hurricanes (category 4 and 5) during the 24th solar cycle were analyzed. Results indicate that alterations in solar activity and CR intensity tend to precede the appearance and intensification of the most powerful North Atlantic hurricanes. The minimum in CR occurs on average 7 days before the peak intensity of the hurricane. The maximum in sunspot number is observed 17 days prior to the hurricane's peak intensity, i.e., 10 days before the CR minimum. Analysis of vertical temperature profiles in the hurricane propagation region suggests the interrelation between temperature variations at the tropopause level and variations in the level of atmospheric ionization by CR. The reduction of the ionization source associated with fluctuations in cosmic rays is suggested to be correlated with a decrease in latent heat release at the tropopause level, which may contribute to a lowering of air temperature, an increased vertical temperature gradient, and enhanced convection.</p> Research highlights <p><UnorderedList Mark="Bullet"> <ItemContent> <p>Forbush decreases during the evolution of 13 North Atlantic hurricanes were explored</p> </ItemContent> <ItemContent> <p>GCR minimum occurs on average 7 days before the peak intensity of the hurricane</p> </ItemContent> <ItemContent> <p>sunspot number maximum observed 10 days before the GCR minimum</p> </ItemContent> <ItemContent> <p>drop in GCR reduces ionization and the temperature in the ion generation peak area</p> </ItemContent> <ItemContent> <p>lower temperatures elevate the altitude temperature gradient and enhance convection</p> </ItemContent> </UnorderedList></p>