Area Code 603-583 located in WINDHAM, ROCKINGHAM, NH, more detail is as below. Place NPA (Numbering Plan Area) : 603 NXX (Local Number Prefix) : 583 City : WINDHAM County : ROCKINGHAM State : NH (New Hampshire) NXX Use Type : Landline NXX Intro Version : 1998-05-18 FIPS (Federal Information Processing Standards) : 33015 LATA (Local Access Transport Area) : 122 Rate Center : EXETER ZIP Code Count : 1 ZIP Code Frequency : 100 ZIP Code : 03087 Other Information NPANXX : 603583 County Population : 0 Switch CLLI (Common Language Location Identifier) : MNCHNHNIDS0 MSA CBSA (Core Based Statistical Area) : Boston-Cambridge-Quincy, MA-NH MSA CBSA Code (Core Based Statistical Area) : 14460 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : LEVEL 3 COMMUNICATIONS - NH OCN (Operating Company Number) : 4017 Coverage Area Name : EXETER Latitude : 42.9797 Longitude : -70.9519 ‹ previous : 603-582 next › : 603-584 Telephone Number List 603-583-0000 ~ 603-583-9999