Environment and Climate Change Canada says hail ranging from the size of a pea to a softball fell in central Alberta on Monday.
Sara Hoffman, who is a meteorologist with the agency, says although the storm that passed through the Rocky Mountain House and Red Deer areas wasn't record breaking, the size of the hail was bigger than expected.
Environment Canada issued a tornado watch in the afternoon that warned large hail might fall from the sky later in the evening.
Videos on social media were posted after the storm of drivers on Queen Elizabeth II Highway pulled over and covering their heads as hail smashed through their windows.
Hoffman says hail the size of baseballs, golf balls, hen eggs, nickels and dimes also fell in Innisfil, Pine Lake, Condor, Rimbey and Ferrier.
She adds the biggest piece of hail fell in 1987 in Alberta and was 17 centimetres in diameter.