Source: https://www.michigan.gov/coronavirus/0,9753,7-406-98178_98455-559589–,00.html

On May 13, 2021, the CDC released guidance indicating the fully vaccinated persons need not wear a mask in most settings, regardless of whether indoors or outdoors. CDC indicated that fully vaccinated persons are at low risk of experiencing symptomatic or severe COVID-19 infection, and pose a reduced risk of transmitting COVID-19 to others. Additionally, recent studies, including a study published in The Journal of Infectious Diseases, confirm that transmission of COVID-19 outdoors is exceedingly rare.

Considering the above, and upon the advice of scientific and medical experts, I have concluded pursuant to MCL 333.2253 that the COVID-19 pandemic continues to constitute an epidemic in Michigan. I have also, subject to the grant of authority in 2020 PA 238 (signed into law on October 22, 2020), herein defined the symptoms of COVID-19 based on the latest epidemiological evidence. I further conclude that control of the epidemic is necessary to protect the public health and that it is necessary to restrict gatherings and establish procedures to be followed during the epidemic to ensure the continuation of essential public health services and enforcement of health laws. As provided in MCL 333.2253, these emergency procedures are not limited to the Public Health Code.