Low Covid-19 risk in Merrimack, New Hampshire.
Moderate Flu activity in Merrimack, New Hampshire.
Low Rsv risk in Merrimack, New Hampshire.
Low Infectious risk in Merrimack, New Hampshire.
Very high Allergy risk in Merrimack, New Hampshire.
Low Pollution risk in Merrimack, New Hampshire.
Low Weather risk in Merrimack, New Hampshire.
Last updated: April 20, 2026
Data refreshed weekly