Maricopa County officials said the West Nile virus season is all but done in the Valley.
David Guerrieri with Maricopa County Vector Control said it has been almost three weeks since any samples tested positive. Still, crews will be going out after midnight to spray for mosquitoes in the East Valley -- Chandler, Gilbert and Mesa -- if weather permits.
"If it's windy the mosquitoes will not fly through the fog and it's a waste of money," he said.
He added the number of West Nile cases this year have been on par with average seasons in Maricopa County.
The drop in temperatures will help push the mosquitoes into their winter stage.