(10.Mai 2000) A correlation between a global average of low cloud cover and the flux of cosmic rays incident in the atmosphere has been observed during the last solar cycle. The ionising potential of Earth bound cosmic rays are modulated by the state of the heliosphere, while clouds play an important role in the Earth’s radiation budget through trapping outgoing- and reflecting incoming radiation. If a physical link between these two features can be established, it would provide a mechanism linking solar activity and Earth’s climate.