The New Hampshire Department of Safety’s Division of Homeland Security and Emergency Management (HSEM) urges residents and visitors to use caution during the dangerous extreme heat expected across most parts of the state through Thursday.

The National Weather Service (NWS) in Gray, Maine, has issued an Excessive Heat Warning for Cheshire, Hillsborough, Merrimack, and Sullivan counties for Monday and Tuesday. Belknap, Carroll, Grafton, Strafford counties, southern Coös County, and interior Rockingham County are under a Heat Advisory for Monday. The NWS expects to issue additional Heat Warnings or Advisories for Tuesday.

Much of New Hampshire is forecast to experience temperatures in the high 90s, with some areas in the southern part of the state potentially exceeding 100 degrees. According to the NWS, extreme heat caused 199 deaths in the United States in 2024.

“It is important to take the proper steps to keep yourself and loved ones safe during extreme heat,” said HSEM Director Robert Buxton. “Stay hydrated and avoid the outdoors if possible. If you must work outside, take frequent breaks. Check in on friends and neighbors, and pay close attention to those who may be more sensitive to the heat, such as the elderly and young children.”

Director Buxton offers these heat safety tips:

• Stay indoors as much as possible and avoid direct sun exposure.
• Never leave children or pets alone in vehicles.
• If air conditioning is not available, stay on the lowest floor—heat rises.
• Know the signs of heat exhaustion and heat stroke.
• Call 211 to find the nearest cooling center in your area.

Visit ReadyNH.gov to learn more about preparing for extreme heat.