Cloud Cover & The Swing Myth

'Overhead conditions' help swing — but not because of humid air. Cloud keeps the pitch and ball cooler and damper, preserving the seam and the shine.

Swing bowling grew with the introduction of the seamed leather ball in the 19th century; the saliva ban (ICC, 2020, permanent 2022) forced a shift to sweat-only shine and wobble-seam variations.

Air viscosity barely changes with humidity (<1%); ball-surface temperature and moisture drive the boundary-layer behaviour.

Bowl first when overhead; bat first when sunny and dry.