The Infectious risk has fallen noticeably over the past 12 weeks, ending the period well below its earlier peak..
Allergy risk activity has been increasing over the past 12 weeks in Mason, Illinois.
No Pollution activity has been reported over the past 12 weeks in Mason, Illinois.
Weather risk activity has been trending downward over the past 12 weeks in Mason, Illinois.
Last updated: August 31, 2026
Data refreshed weekly