Public Health Ontario is reporting that as of Tuesday, there have been 82 confirmed or probable West Nile infections in the province this year.
Ontario is far and away the hardest hit province so far this year.
Quebec, Alberta, Manitoba and Saskatchewan have also reported human cases, but their numbers are far lower so far.
To date there have been no fatal cases this year in Canada.
The public health agency says so far Ontario's West Nile activity has been reported only in the southern part of the province.
Ontario's record year was 2002, when the province had 394 cases and 19 deaths.
On Wednesday, the United States also reported a lot of West Nile activity this year, with 1,590 human cases reported so far, including 66 deaths.
The U.S. total — based on figures calculated as of Aug. 28 — is the highest figure to the end of August since West Nile was first emerged there in 1999.
Over 70 per cent of cases in the U.S. so far this year have been reported from six states —Texas, South Dakota, Mississippi, Oklahoma, Louisiana and Michigan, according to information released by the U.S. Centers for Disease Control.
In fact, over 45 per cent of all cases have been reported from Texas.