Officials with the World Health Organization said they're seeing a 131% increase in new cases, in the last seven days.
California's own case rates have led the state health department to update guidelines on mask-wearing indoors.
Health officials, now aligning with guidance from the Centers for Disease Control and Prevention, recommended everyone needs to wear a mask indoors, even if they're vaccinated.
#BREAKING Following CDC guidance, the California Dept. Of Public Health has updated its Guidance for Face Coverings, recommending mask use for indoor public settings, regardless of vaccination status. @ABC30— Jessica Harrington (@JessicaABC30) July 28, 2021
"The city is not mandating mask wearing for everyone. We are, though, monitoring daily what our positivity rate is," said Fresno Mayor Jerry Dyer.
His remarks come the same day the California Department of Public Health announced it is recommending mask use for indoor public places, regardless of vaccination status.
RELATED: California health officials recommend wearing face mask indoors even if you're vaccinated
State health officials said the recommendation is to slow the spread of the Delta variant.
Fresno and Kings County health departments recently made the same recommendation.
"We felt it was important for the vaccinated people to understand that if they happen to be one of those breakthrough infections, which was more likely in areas with a huge amount of transmission and disease, that those people could potentially pass it on to somebody, a loved one immunosuppressed," said CDC Director Dr. Rochelle Walensky.
Under the CDC's new guidance, 90% of California's population is currently in areas where the transmission rate is substantial or high.
In the Central Valley, Fresno, Madera and Tulare counties have a substantial transmission rate.
Under the CDC’s new guidance, more than 90% of California’s population is in areas designated as substantial or high transmission. Fresno, Tulare & Madera county are in substantial transmission rates. @ABC30— Jessica Harrington (@JessicaABC30) July 29, 2021
Link to website: https://t.co/RlKY4omFkH pic.twitter.com/fTRcdAHneO
Merced, Mariposa and Kings County have a high transmission rate.
However, Dyer said there need to be incentives for people to get vaccinated and one incentive is not having to wear a mask.
"I believe if we put in a city-wide mandate for people to wear masks, the question is going to be, 'Then why did I get vaccinated?'" Dyer said.
. @MayorJerryDyer says based on Fresno County’s current positivity rate he will not require vaccinated city employees to wear masks at work. He also doesn’t believe the city needs a mask mandate at this time. @ABC30 pic.twitter.com/dcyc2rXy3e— Jessica Harrington (@JessicaABC30) July 29, 2021
Currently, City of Fresno employees have to wear a mask at work, unless they can prove they are vaccinated.
However, Dyer said they are discussing making weekly COVID-19 testing mandatory for unvaccinated employees.
Dyer said based on Fresno County's positivity rate and vaccination rate, he doesn't see the need for a current mask mandate.
"I think we're in a good place," Dyer said. "That's not to say, in a week or two, that we may see some type of outbreak or spread that we need to be flexible."
Wednesday evening, the Fresno County Department of Public Health released preliminary COVID-19 trends for youth.
Fresno Health Department officials said they are seeing the number of emergency room visits for COVID-19 symptoms in people 18 and under exceed the number of visits by people 65 and older.
They're also seeing a rise in positive Covid cases in people ages 10 to 30 years old.
As students go back to school, the Fresno County Health Department is anticipating another rise in COVID cases in young people.