The weekly report from the federal Centers for Disease Control and Prevention shows ten of Arizona's 15 counties are now classified as having high community transmission rates of COVID-19.
Pima, Cochise, Santa Cruz, Graham, and Greenlee counties are rated as having medium transmission rates. Most of those counties had low rates the week before.
Yuma County saw the largest change, according to the CDC, the western county saw a 280% change in its seven-day average of COVID cases.
Health officials recommend wearing a mask indoors if you live in, or visit, a county with a high transmission rate.