N.H. Code Admin. R. Env-A 1102.02
(a) Unless exempted by Env-A 1102.03, the owner or operator of a motor vehicle shall comply with the idling limitations specified in Table 1100-1, below, subject to the note in (b), below:
Table 1100-1: Idling Limitations for Motor Vehicles
Temperature
in degrees Celsius (degrees Fahrenheit)
Maximum Idling Time
Above 0° C (32° F)
No more than 5 consecutive minutes in any 60-minute period
At or between -23°C (-10°F) and 0°C (32°F)
No more than 15 consecutive minutes in any 60-minute period
Below -23° C (-10° F)
No limit A
Source. #10345, eff 5-22-13; ss by #13680, eff 7-1-23