Infectious risk activity has been stable over the past 12 weeks in Loudoun, Virginia.
Allergy risk activity has been increasing over the past 12 weeks in Loudoun, Virginia.
No Pollution activity has been reported over the past 12 weeks in Loudoun, Virginia.
Weather risk activity has been increasing over the past 12 weeks in Loudoun, Virginia.
Last updated: May 25, 2026
Data refreshed weekly