Infectious risk activity has been decreasing over the past 12 weeks in Merrimack, New Hampshire.
The allergens risk has shown a notable increase over the last 12 weeks, with levels rising steadily and remaining elevated in the most recent week compared to earlier weeks..
The pollution risk has consistently remained very low and stable with no significant changes observed over the last 12 weeks..
The Severe Weather risk index has fluctuated over the past 12 weeks but exhibits an overall increasing trend, with the current week showing a higher risk relative to several prior weeks..
Last updated: May 24, 2026
Data refreshed weekly