Portsmouth, NH to Portland Harbor, ME map preview
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Portsmouth, NH to Portland Harbor, ME Marine Weather Route Forecast

Popular leg for cruisers heading into the Gulf of Maine.

Latest Automated Forecast

Optimized for marine passage planning, vessel routing, and coastal or offshore weather tracking. This automated marine weather routing tool updates daily using premium data models. Below is the weather, wave, and ocean current layout for a standard vessel transit from Portsmouth, NH to Portland Harbor, ME.

Generated: 2026-07-28T11:15:42.029791+00:00 • Distance: 54.2 NM • Departure: 2026-07-28T08:00:00-04:00 • Speed: 6 knots
Time Wind Waves Ocean Current Air/Water
2026-07-28T12:00:00+00:00 3.0777549000000004 kts 0.58 m 0.2 kts E E 19.1 / 17.0 °C
2026-07-28T16:00:00+00:00 6.965445300000001 kts 0.78 m 0.4 kts N N 18.3 / 18.4 °C
Locked forecast rows are available to signed-in users.

Route Passage Summary & Sea State

Expect mixed conditions with no major headwinds. Winds range from 2 to 11 kts with waves 1.9 to 2.8 ft with period of 6 to 7 seconds. Overall, wind and waves mostly aligned or partially aligned. Wind angles: 50% following, 50% reaching. Sea state: 75% aligned, 25% cross-seas.

Historical Forecasts Download GPX File

Related Routes

Portland Harbor, ME to Portsmouth, NH
53.8 NM 14 waypoints
Boothbay Harbor, ME to Portland Harbor, ME
33.9 NM 10 waypoints
Provincetown Harbor, MA to Portland Harbor, ME
105.8 NM 10 waypoints
Gloucester, MA to Portsmouth Harbor Inlet, NH
35.9 NM 8 waypoints

Navigation Responsibility

This forecast is for informational purposes only. You are responsible for your own navigation and safety at sea. Always verify weather conditions with official sources, maintain a proper watch, and exercise prudent seamanship. Do not rely solely on this forecast for critical navigation decisions. See our Terms of Service for full details.