Winnipeg's mosquito fogging trucks are set to hit the road tonight for the first time this season, with central, western and northwestern neighbourhoods due to be sprayed.

Weather permitting, fogging will run from 9:30 p.m. Thursday to 6:30 a.m. Friday in insect management areas 35 to 39 and 42 to 51.

Combined, the fogging area covers much of central, western and northwestern Winnipeg west of the Red River and north of the Assiniboine River, with the exception of the downtown and Sturgeon Creek areas, where fogging ends at Portage Avenue.

It includes neighbourhoods around Winnipeg James Armstrong Richardson International Airport, the St. James industrial area and Kildonan Park.

Check the City of Winnipeg's nuisance mosquito fogging schedule to see if your block is scheduled to be fogged.

Weather permitting, City of Winnipeg mosquito fogging trucks will run from 9:30 p.m. Friday to 6:30 a.m. Saturday in the areas shaded in blue. (City of Winnipeg)

The city said crews will respect buffer zones and won't spray within 90 metres on each side of a registered property on the front street, side street, and rear lane.

The weather forecast may not work in favour of fogging crews — Environment Canada is calling for a 60 per cent chance of showers overnight, with a risk of a thunderstorm.

Level set to high

The Insect Control Branch has been battling the bugs through a combination of larviciding and residual treatments, but it's no longer enough, officials said Wednesday.

The scale to decide whether to spray for mosquitoes moved from medium to high on Wednesday after traps in a few areas of the city swelled to more than 200. The city-wide average trap count was 37 on Monday and has increased to 140.

While the city is planning to move away from using the insecticide malathion in the future, crews will be using it again this year, as they have 4,550 litres remaining — enough to fog the city 2½ times, said Ken Nawolsky, Winnipeg's superintendent of insect control.

An alternative will not be available this summer, he said, adding he's confident the current malathion supply will last the season.

Nawolsky said if the weather is on their side, the mosquito count can be significantly reduced in about a week.