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.
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.
This page was last updated on July 3, 2015.