Severe hail frequency over Ontario, Canada: Recent trend and variability

Over the last two decades, there is an ever-increasing frequency of severe hail events occurred in Ontario, Canada. This upward trend is robust as verified through the MK test with consideration of removing a lag one autoregressive process. It is shown through the composite analysis that the severe hail frequency is closely linked with the atmospheric convective instability and precipitable water. It is also demonstrated that the high-hail-event years are associated with warmer air temperature than the low-hail-event years, indicating that the severe hail events occur more frequently in the warming climate.