The salmon run in Ontario generally starts in late summer and peaks through the fall, with the best viewing and fishing usually in September and October.

Quick Scoop

  • Salmon can begin entering some Ontario rivers as early as late July or August if water levels and temperatures are right, but these early runs are smaller and sporadic.
  • The peak salmon run on most popular rivers is from mid‑September to mid‑October, often lining up with the period just before and around Thanksgiving.
  • Runs are strongly triggered by cool water temperatures and higher flows after heavy rain; many anglers plan outings 1–3 days after a good rainfall.
  • On some systems, salmon may still be running into early November, though this is more the tail end of the season rather than the main spectacle.

How It Varies Across Ontario

  • Great Lakes tributaries (Lake Ontario, Huron, Georgian Bay) tend to see major Chinook and coho runs from early/mid‑September through October, with exact timing shifting year to year based on weather.
  • In the Greater Toronto Area (Credit River, Humber, Duffins, etc.), the most reliable viewing window is mid‑September to Thanksgiving weekend, depending on rainfall and warm falls.
  • Tourist information for places like Port Hope (Ganaraska River) similarly highlights September and early October as prime time to see dense runs at fish ladders and dams.

Practical Tips if You Want to Go

  • Aim for:
    • Time of year: mid‑September to mid‑October.
    • Time of day: early morning or evening when it’s cooler and fish move more actively.
* Weather: a day or two after substantial rain, when rivers rise and turn on the migration.
  • Check local river or municipality pages before you go; some stretches close to protect spawning fish, and Ontario regulations vary by zone and river section.

If you want the classic “river full of salmon leaping at falls or fish ladders” experience in Ontario, plan around a cool, rainy stretch sometime between mid‑September and Thanksgiving, then watch water levels and head out right after a rise.

Information gathered from public forums or data available on the internet and portrayed here.