Markham, ON F1 Tornado of August 8, 1992

York - Durham

This tornado was witnessed as it touched down in Markham at about 4:30 pm. Its track was four kilometres long and 300 metres wide, along which there was extensive tree damage. In addition, a tractor trailer was flipped over and the roof was torn off of a barn. This was one of two tornadoes to touch down in Southern Ontario on August 8th.

Figure 1 depicts the surface chart at 2:00 pm EDT, which shows a warm front moving east across southern Ontario. This front was the focus for intense thunderstorms throughout the day. This warm front was responsible for a long-track tornado in Chatham-Kent, ON earlier in the day.

Figure 1. Surface analysis at 18Z on August 8, 1992 showing mean sea-level pressure (MSLP) contours, surface observations, fronts and pressure centres (WPC, 2017).

According to Environment and Climate Change Canada (2018), an F1 tornado touched down at 4:30 pm EDT in Markham, ON. The tornado travelled for 4 km and had a maximum width of 300 metres. The tornado caused no fatalities, injuries or property damage.


NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 18Z Sat Aug 8 1992. Retrieved from:

Environment and Climate Change Canada Data. (2018). Canadian National Tornado Database: Verified Events (1980-2009) – Public. Retrieved from: