The web site New York Metro has published a list of the nice outdoors places where to have a a dinner.
Trestle on Tenth (242 Tenth Ave., at 24th St.), The Farm on Adderley (1108 Cortelyou Rd., nr. Coney Island Ave., Ditmas Park, Brooklyn) and Enoteca Barbone (186 Ave. B, nr. 11th St.), The Good Fork (391 Van Brunt St., nr. Coffey St., Red Hook, Brooklyn), Pies-N-Thighs (351 Kent Ave., at S. 5th St., Williamsburg, Brooklyn) are mentioned as a good choices.
It is time to get out of Manhattan, at least for a few hours. Threee of those restaurants are in Brooklyn.