The road skirts the south side of Portsmouth International Airport at Pease.

The route travels northeast, passing by Stratham Hill Park and curving to the east before crossing into the town of Greenland.

[citation needed] NH 33, which is initially Greenland Road upon entering Portsmouth, passes the southern entrance to Pease International Tradeport then interchanges with Interstate 95 at a partial cloverleaf interchange (exit 3) and continues to the east, becoming Middle Road.

[citation needed] The last eastbound and first westbound markers for NH 33 are at its intersection with Islington Street approximately 1 mile (1.6 km) west of US 1.

NH 33 is unsigned from both Middle Street and Lafayette Road, and no other guide signs are present in the downtown area.