The Infectious risk has shown a gradual increase over the last 12 weeks, ending the period at its highest level..
Allergy risk activity has been trending upward over the past 12 weeks in Chester, Pennsylvania.
No Pollution activity has been reported over the past 12 weeks in Chester, Pennsylvania.
Weather risk activity has been trending upward over the past 12 weeks in Chester, Pennsylvania.
Last updated: August 31, 2026
Data refreshed weekly