The Infectious risk has stayed within a narrow range over the past 12 weeks, with the most recent week close to the 12-week average..
Allergy risk activity has been easing over the past 12 weeks in Harford, Maryland.
Pollution risk activity has been climbing over the past 12 weeks in Harford, Maryland.
Weather risk activity has been increasing over the past 12 weeks in Harford, Maryland.
Last updated: July 13, 2026
Data refreshed weekly