Millgrove, ON EF1 Tornado of August 2, 2015

City of Hamilton

This EF1 tornado struck the community of Millgrove in northwest Hamilton, damaging trees and houses. It touched down at about 10:00 pm, with a path that was 1.7 km long and 200m wide.

Many trees were snapped and uprooted, and others left standing had large branches torn off and thrown. Several houses suffered minor damage but, at one property, a section of the home’s roof was removed. In addition, a fabric gazebo was torn apart, its metal frame twisted and destroyed, and a municipal salt dome was demolished.

This was one of four tornadoes that touched down on August 2, 2015. The others:

  • Teviotdale (EF2)
  • Lebanon (EF2)
  • Marsville (EF1)
Figure 1. Surface analysis at 03Z on August 3, 2015 showing mean sea-level pressure (MSLP) contours, surface observations, fronts and pressure centres (WPC, 2017)

Figure 1 depicts the surface observations at 11:00 pm EDT, which shows a squall line (line of thunderstorms) moving across southern Ontario and Lake Ontario. This line of storms was responsible for several strong tornadoes across southern Ontario in the late-evening hours of August 2nd.

Figure 2. Doppler radar reflectivity at 10:43 pm EDT (source:

Figure 2 shows the squall line moving across the GTA in southern Ontario.


NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 03Z Mon Aug 3 2015. Retrieved from: