What to know
- August and September are peak seasons for mosquitoes in Toronto, which can bring itchy bites and West Nile Virus.
- Toronto Public Health have already confirmed the first reported case of West Nile Virus in 2026. In 2025, there were 78 reported cases.
- Health professionals recommend wearing long sleeves, and bug sprays with 30 per cent DEET or 20 per cent Icaridin to keep yourself protected.
As the weather continues to heat up in Toronto, residents are seeing mosquitoes show up in hoards, and officials have confirmed the presence of West Nile Virus in the city. Here’s what you need to know.
One of the city’s least favourite seasonal visitors, mosquitoes, are most prominent in August and September, especially after heavy rainfall. Mosquitoes not only bring uncomfortable bites and itchiness, they can also carry the deadly West Nile Virus.
At the end of July, Toronto Public Health reported its first case of West Nile Virus in 2026. In 2025, the city logged a total of 78 cases.
Symptoms of West Nile Virus can develop anywhere between two and 14 days after being bitten. Symptoms can include a fever, a headache, nausea, vomiting, body aches, rash, swollen lymph glands, and a stiff neck.
To avoid being bitten by mosquitoes, Dr. Isaac Bogoch, an infectious disease specialist at Toronto General Hospital, says it’s helpful to wear a long-sleeve shirt and long pants, which isn’t the most practical in Toronto’s stifling heat.
He also says if wearing protective clothing is off the table, the insect repellent sprays are “very effective in preventing bug bites.”
Bogoch recommends products that contain 30 per cent DEET or 20 per cent Icaridin. For people who wear clothing made of synthetic or plastic material, bug sprays containing icaridin may be more appropriate, as DEET can dissolve plastics.
Toronto Public Health also recommends dumping any stagnant water, as it’s an ideal breeding ground for mosquitoes.
Most individuals infected with West Nile Virus recover on their own, but if symptoms worsen, you are urged to seek medical care.
