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Lightning Maps and Statistics

The table below shows the number of cloud-to-ground lightning flashes recorded in Canada from 1999 to 2008. The numbers range from a maximum of 2.963 million flashes in 2005, to the minimum of 1.984 million flashes in 2008.

Number of cloud-to-ground lightning flashes in Canada, from 1999 to 2008, broken down by year

The table below shows the average number of lightning flashes in Canada, broken down by month. As you can see, July is the month that has the most lightning strikes, followed by August and June. It is interesting to note that lightning is reported in Canada in every month of the year.

Average monthly cloud-to-ground lightning in Canada (1999 to 2008)

The length of the lightning season varies greatly across Canada, but shows one distinct pattern: the season becomes shorter the farther north one goes. In the North, the average season runs from mid-to-late May until late August-mid September. Over southern Ontario, the average lightning season extends from mid-March to early November. Lightning occurs virtually year round in the Pacific coastal region, over southern Nova Scotia, and offshore. 

Average date of beginning of the lightning season for Western and Eastern Canada (1999-2008) 

Average date of the end of the lightning season for Western and Eastern Canada (1999-2008) 

Most of us associate lightning with thunderstorms that form during the day, driven by the heating that comes from the sun. However, in some areas of the country nocturnal lightning (lightning that occurs at night) can account for almost half of all lightning. This is seen over portions of east-central Alberta and the southern halves of Saskatchewan and Manitoba, with an extreme of 65.7 per cent nocturnal lightning near Quill Lake, Saskatchewan. 

Percentage of lightning occurring between 10:30 p.m. and 10:30 a.m. local time for Western and Eastern Canada (1999-2008)

Fast Canadian lightning facts

• The approximate number of cloud to ground lightning flashes detected in Canada since the Canadian Lightning Detection Network (CLDN) began in 1998 is 23.5 million. 
• The average number of lightning flashes per year in Canada is 2.3549 million.
• The minimum number of lightning flashes in Canada in one year was 1.9835 million in 2008.
• The maximum number of lightning flashes in Canada in one year was 2.9631 million in 2005.
• The northern most lightning flash detected in Canada was 70.8811 degrees North, 130.5910 degrees West (over eastern Beaufort Sea north of Tuktoyaktuk)
• The month that is likely to have the most number of lightning flashes in Canada is July.
• The most frequent time of day for lightning is between 1 p.m. and 5 p.m. local time.
• The greatest 10-year average number of days with lightning in Canada is an average of 35.9 a year, near Harrow, Ontario.
• The Canadian region with the greatest annual number of days with lightning is inland of the north shore of Lake Erie near Highgate, Ontario.
• The Canadian city with the greatest number of days with lightning in any one year is Windsor, Ontario, which had 47 days of lightning.