N.Y.C. Admin. Code § 24-242: § 24-242 Lawn care devices.

(a) No person shall operate or use or cause to be operated or used any lawn care device:

(1) On weekdays before eight a.m. and after seven p.m. or sunset, whichever occurs later; or

(2) On weekends and New York state and federal holidays before nine a.m. and after six p.m.; or

(3) At any time in such a way as to create an unreasonable noise. For the purposes of this section unreasonable noise shall include but shall not be limited to an aggregate sound level of 75 dB(A) or more, attributable to the source or sources, as measured at any point within a receiving property. The provisions of paragraph (1) of this subdivision shall not apply to an employee of the department of parks and recreation or an agent or contractor of the department of parks and recreation who operates or uses or causes to be operated or used any lawn care device between the hours of seven a.m. and eight a.m. in any location more than three hundred feet from any building that is lawfully occupied for residential use. The distance of three hundred feet shall be measured in a straight line from the point on the exterior wall of such building nearest to any point in the location at which such lawn care device is operated or used or caused to be operated or used.

(b) No person shall operate or use or cause to be operated or used any leaf blower not equipped with a functioning muffler.