1. World Map/
  2. North America/
  3. US/
  4. Area Codes/
  5. Area Code 603

Where Is Area Code 603?

Area code 603 is found in the US state of New Hampshire. Servicing the entire state, area code 603 includes the city of Manchester (population: 114354), and all 10 counties of New Hampshire.

Located in the Eastern time zone, area code 603 is on the same time as New York, NY.

Area code 603 was brought into effect on January 1, 1947.

Map of  with area code 603 highlighted

Counties in Area Code 603

  • Belknap,
  • Carroll,
  • Cheshire,
  • Coos,
  • Grafton,
  • Hillsborough,
  • Merrimack,
  • Rockingham,
  • Strafford,
  • Sullivan.

Most Populous Cities in Area Code 603

City County City Population Time Zone
Manchester Hillsborough 114,354 EST
Nashua Hillsborough 86,968 EST
Concord Merrimack 48,636 EST
Derry Rockingham 33,561 EST
Dover Strafford 30,277 EST
Rochester Strafford 30,051 EST
Salem Rockingham 29,029 EST
Merrimack Hillsborough 25,616 EST
Keene Cheshire 25,192 EST
Hudson Hillsborough 24,614 EST
Londonderry Rockingham 24,167 EST
Portsmouth Rockingham 21,721 EST
Bedford Hillsborough 21,319 EST
Exeter Rockingham 21,139 EST
Laconia Belknap 16,026 EST
Hampton Rockingham 15,479 EST
Milford Hillsborough 15,168 EST
Durham Strafford 14,754 EST
Claremont Sullivan 13,887 EST
Windham Rockingham 13,711 EST
Goffstown Hillsborough 13,634 EST
Hooksett Merrimack 13,402 EST
Pelham Hillsborough 12,967 EST
Somersworth Strafford 11,917 EST
Suncook Merrimack 11,461 EST

Note: The above list is based off of the top 25 most populous cities in the area code as per 2012 United States Census Bureau estimates.

View all United States Area Codes.

Trending on WorldAtlas

This page was last modified on July 3, 2015.