Sarnia-Lambton has advanced to Stage 3 as of 12:01 a.m. Friday.
Restaurants, bars and gyms across the county have been given the green light to reopen.
Lambton County Warden Bill Weber said as businesses open their doors to patrons, it's important residents remember that it's not exactly back to normal yet.
"Things are opened up and COVID has still not gone away and social distancing is still important," said Weber. "When you can not social distance we strongly recommend and encourage that you wear a mask to protect yourself and others. We have to still remain vigilant against the virus."
Lambton Medical Officer of Health Dr. Sudit Ranade said as we move into Stage 3, it's expected we will see an uptick in cases of COVID-19.
"A lot of different provinces are finding that as they open up they have been seeing clusters related to increased socializing behaviour," he said. "So people say 'it's Stage 3, I can do so many things, why can't I have this party or go out and see different friends every night' and all that stuff. It's really that type of behaviour, the close socializing, that really drives the movement of this infection."
As part of Stage 3, gathering limits have increased to a maximum of 50 people indoors and a maximum of 100 people outdoors, with physical distancing in place.
Gathering limits do not apply to settings such as beaches, parks, restaurants and bars, but measures to enable physical distancing may limit capacity at any given time.
