The Infectious risk has trended steadily upward over the past 12 weeks, reaching a notably higher level in the most recent week compared to prior weeks..
Allergy risk activity has been trending upward over the past 12 weeks in Merrimack, New Hampshire.
No Pollution activity has been reported over the past 12 weeks in Merrimack, New Hampshire.
Weather risk activity has been easing over the past 12 weeks in Merrimack, New Hampshire.
Last updated: August 24, 2026
Data refreshed weekly