Nassau County grounded a plan to spray pesticides over much of the county Thursday evening due to the wind.
The aerial assault was to be an effort to stop the spread of the West Nile virus.
The spraying was supposed to start around 6 p.m., or dusk, in the area bordered by the LIE and Southern State Parkway, and the Seaford-Oyster Bay Expressway to the Queens line to the east and west.
Health officials made the decision to spray after 49 pools of mosquitoes tested positive for the virus.
Health officials say they will try to carry out the plan next week.
One death in Nassau has been blamed on West Nile virus this year.