Results from mosquito traps show a significant increase compared to the same time last year, a consulting firm hired by the city to monitor and control mosquito populations reported.
A long, cool and wet spring allowed early mosquito varieties to thrive and they've stayed around, GDG Environment project manager Mark Ardis said.
"Compared to years past, especially the past three years, mosquito populations are much higher than what we've observed in the past," Ardis told the Canadian Broadcasting Corp.
"We've got spring mosquitoes and we've got these early summer mosquitoes, and now we're going to see what we call cat-tail marsh mosquitoes emerging as well," he said. "So we're going to see I guess a triple whammy of mosquitoes emerging within the next few days."
Of the 20 or so mosquito species that breed in Ottawa, only one carries West Nile virus, authorities said, and with species only starting to emerge the virus hasn't yet been detected in the region.