The answer is as varied and nuanced as the species, which has an extensive natural range extending from the central California coast up through the PNW, BC, Alaska, and over to Kamchatka. In many of the larger systems, pre-European settlement, there was a near continuum of returning fish, and these days the run timing is narrower and more defined. To overgeneralize, we refer to winter steelhead, and summer steelhead runs, though many summer fish return in the fall and many winter fish return in the spring. Summer fish tend to travel a reasonable distance inland and spend roughly six months in freshwater, while winter fish tend to travel less than 150 miles inland and often spend less than six weeks in freshwater. All and all, there are many months each year in which steelhead can be targeted, with some windows being more productive and pleasant than others.
To break it down, I will lump the discussion into regions and give a quick overview of the timing and opportunities in each area.
California, Oregon, and Washington:
This region we often call the Pacific Northwest has both summer and winter steelhead. The majority of the larger systems that originate from interior snow-fed mountains (Sacramento, Klamath, Rogue, Umpqua, Columbia, and Willamette) have summer fish enter into their lower reaches as early as June and July though in many cases, they are best targeted later in the season once they arrive in the smaller, cooler, more fishable upper reaches of their home systems. Broadly speaking, July is often the early end of the quality fishing on the lower Klamath, the Rogue, Umpqua, and lower Columbia tributaries. With that said, these same rivers are often at their prime in the September through November window. These same summer fish can be targeted well into February and early March, as many will only spawn in March and April.
Winter returns in the PNW can begin as early as late November, typically after the first big pushes of winter rain. Prime time is often January through March. Fisheries like the North Umpqua, the northern Oregon coast, and the Olympic Peninsula can fish well into mid-April.
British Columbia:
There is much to discuss in BC, but for practical purposes, we will limit the summer steelhead talk to the Dean and Skeena systems. The Dean fires off first, with the first steelhead tickling into the lower river in late June. In July, the migration into the Dean beneath the falls peaks, and the number of new fish dwindle as August progresses. Above the falls, the fishing improves throughout July and is at its best in August and September. The river closes on October 1st. The Dean is not a winter fishery.
Further north on the lower Skeena, summer fish begin migrating inland in July. Typically, the heaviest in-migration occurs in the first two weeks of August. For anglers wanting to fish in July and August, be sure to focus on the greater Terrace region, as the fish need some additional time to make it to the upper tributaries. The Babine, Bulkley, Morice, Kispiox, and Sustut start fishing at the end of August and are at their best in September and October. Most of the lodges close in late October or early November, not because of a lack of fish but because it tends to get too cold to make fishing pleasant and practical. With that said, on mild years, I know folks who have a tradition of going out and swinging up a steelhead on Christmas morning! These fish will typically spawn in May.
Winter fishing on the Skeena is another nuanced deal. All winter fishing is limited to the lower Skeena and its tributaries in the greater Terrace region. If there is a mild winter and the lower reaches of the Skeena don't freeze over, you can catch nice fish in January, February, and March. Most of the outfitters don't take guests until the last week of March, and they continue to fish through the end of April. These are definitely the peak weeks.
