Salmon and Sea Trout Runs: When They Happen in the UK

By Alex Clayton · Updated 23 October 2026

Most anglers picture the salmon run as an autumn event. Salmon actually enter UK rivers through much of the year in separate waves: big multi-sea-winter fish early in the year, grilse mainly from June to August, and more fish moving upstream once autumn rain arrives. Autumn salmon fishing is the best-known part of a much longer calendar, and timing on one river can differ sharply from the next.

Below: the run calendar, grilse versus spring fish, why the back end depends on rain, the sea trout run, and season dates and release rules for England, Wales and Scotland. Northern Ireland has its own rules, so check with DAERA if you fish there. For the wider season, see our autumn fishing guide.

When Do Salmon Run in the UK? The Year at a Glance

One table tells you what is most likely to be entering rivers in any given month.

In England and Wales, salmon enter rivers throughout the year. Three-sea-winter fish mostly arrive early in the year, grilse mainly from June to August, and two-sea-winter fish can arrive in any month, with spring, summer or later peaks depending on the river. That pattern comes from section 7.3 of the Environment Agency and Cefas 2024 salmon stocks background report, and it is the most dependable answer to when the salmon run UK anglers talk about actually happens.

Period	Fish most likely entering	Notes
Early year to May	Spring fish: three-sea-winter and early two-sea-winter salmon	Few three-sea-winter fish enter after May. In England, every salmon caught before 16 June must be released (see the release rules below).
June to August	Grilse (one-sea-winter fish), the main summer run	Two-sea-winter fish also arrive on some rivers.
September to season end	Later two-sea-winter fish, plus fish that ran earlier and held in pools or tidal reaches	Autumn rain moves both groups upstream.
Sea trout	Varies by river	Check with the local fishery or rivers trust.

Read the table as a pattern, not a timetable. The report’s figures cover England and Wales only. Scottish rivers are outside that dataset, and every river has its own character: some are known for spring fish, others fish best late.

For a specific river, the only reliable guide is its own catch records, kept by the fishery or the local district salmon fishery board. Before you book a trip, ask for catch returns by month and compare them with the dates you have in mind. For how sea age fits into the wider Atlantic salmon life cycle, see our species guide.

Spring Fish, Grilse and Multi-Sea-Winter Salmon Explained

The summer grilse river many anglers remember is less common than it was. According to the 2024 salmon stocks summary report, multi-sea-winter fish have made up more than half of the adjusted rod catch in England and Wales on average over the past 14 years, against about a quarter before that, as grilse numbers have fallen.

Three terms cover most of what you will hear on the bank:

Grilse: a salmon that has spent one winter at sea (1SW) before returning to its river.
Multi-sea-winter (MSW) salmon: a fish that has spent two or more winters at sea (2SW or 3SW). It is larger, having fed longer at sea.
Spring fish: the early-running MSW salmon that enter rivers in the first months of the year.

Sea age drives the calendar. The fish that have spent longest at sea return earliest, with three-sea-winter fish mostly in the river before June. The grilse run falls in summer because those fish come back after a single winter, and two-sea-winter fish sit between the two, turning up in any month.

Early MSW fish get special protection. The National Spring Salmon measures, in place since 1999, require every salmon caught in England before 16 June to be released, so these early fish can reach the spawning beds.

The practical difference: grilse arrive mainly in summer and may be kept on some rivers where the rules allow, while spring fish arrive early and are protected by law.

Autumn Salmon Fishing: Why Rain Starts the Back End

A week booked for late September can turn into a week of low, clear water and stale fish if the rain does not come. Autumn salmon fishing runs on the weather, not the calendar.

Anglers call the final weeks of the season “the back end”, and it starts when meaningful rain falls and temperatures drop, not on a fixed date. Writing in The Field, Mungo Ingleby put that turning point at around 10 September in 2022 and about 25 September in 2021 on Scottish rivers. He also noted that much autumn sport is for fish that ran earlier or waited in tidal reaches, and that big fresh autumn runs have been largely absent on many Scottish rivers since 2014. That is one writer’s observation, not data.

On a spate river, the best chance usually comes as the water drops and starts to clear after a rise. Before you travel, check river levels on the official services: the Environment Agency’s river and sea levels service in England, Natural Resources Wales’ river levels, rainfall and sea data and SEPA water levels in Scotland.

Most Welsh rivers close on 17 October and several south west England rivers on 1 October or earlier, so back end salmon fishing there is short, while some Scottish districts have run into November (see the season table below).

Back end fishing suits anglers who can go at short notice. On spate rivers, avoid fixed-date bookings unless the fishery confirms there is water. For how to fish it, see our salmon fishing techniques guide.

Sea Trout Runs and Finnock: What to Expect

Ask when the sea trout run starts and you will get a different answer on every river.

There is no single official UK calendar for it. Ask the fishery, angling association or rivers trust for catch records by week or month.

You will also hear about finnock. The Environment Agency’s Celtic Sea Trout Project describes these as sea trout that return to the river in the same year they went to sea.

Sea trout seasons are set separately from salmon:

Wales: most rivers are open 20 March to 17 October, and Anglesey 1 May to 17 November (NRW sea trout seasons). Sea trout over 60cm must be released.
North West England: the migratory trout close season runs 1 October to 31 March.
North East England: the sea trout close season runs 1 November to 2 April in both the Northumbria and Yorkshire areas (GOV.UK North East byelaws).
Scotland: sea trout are classed as salmon in law, so the district rules set for salmon apply to them too (Fisheries Management Scotland).

Much summer sea trout fishing is done at night. For method, see our sea trout fishing guide, and for the fish itself, our sea trout species guide.

To target the sea trout run, ask which weeks produce fish, then check that river’s close season.

When the Salmon Season Ends: England, Wales and Scotland Compared

On the Dorset Frome the salmon close season starts on 1 September. Under Scotland’s 2014 order, the Nith allowed rod fishing until 30 November, three months later.

In England, close seasons vary by region and river, so the local byelaw decides (GOV.UK national rod fishing byelaws).

Nation / area	Salmon close season or season end	Source to check
England, North West	Close season 1 November to 31 January (River Eden 15 October to 14 January)	GOV.UK North West byelaws
England, North East	Northumbria area 1 November to 31 January; Yorkshire area 1 November to 5 April	GOV.UK North East byelaws
England, South West	Varies by river: Exe, Teign, Dart, Taw and Torridge close from 1 October; Tamar, Tavy and Lynher from 15 October; Frome, Piddle and other Wessex rivers from 1 September; Devon Avon 1 December to 14 April; Camel, Fowey, Looe and Plym 16 December to 31 March	GOV.UK South West byelaws
Wales	Most rivers open 20 March to 17 October; Wye, Usk and Dee open from 3 March; Teifi, Tywi, Aeron and Cleddau from 1 April; Severn in Wales 1 February to 7 October; Anglesey 1 May to 17 November; lower Conwy, lower Dyfi and Dwyryd to 31 October	NRW salmon open seasons
Scotland	Set by salmon fishery district. Under the 2014 order, rod fishing ended on dates including 30 September (Spey, Findhorn), 15 October (Beauly, Ness), 31 October (Ayr, Bladenoch), 15 November (Annan) and 30 November (Nith)	SSI 2014/327, the Scottish Government and the district board
Northern Ireland	Not covered here	DAERA

The Scottish dates come from the 2014 order as made and may have been amended since, so confirm them with the Scottish Government and the fishery. English rules may also change: the Environment Agency is considering a new national salmon byelaw.

In the North East, no salmon or migratory trout fishing is allowed from the first hour after sunset to the first hour before sunrise, unless you use a fly with hooks that pass through a 10mm tube.

Southern England and Wales close earliest, so plan late-season trips further north. For other species, see UK fishing close seasons, and check with the fishery before you travel.

Can You Keep a Salmon? Release Rules by Nation

Landing your first salmon is a bad moment to start reading byelaws.

England: all salmon caught before 16 June must be released, and before that date only artificial fly or lure may be used. Many rivers are all-release for the whole season, including the Eden, Border Esk and Lune in the North West, the Aln, Wansbeck and Yorkshire Ouse in the North East, and the Camel and Severn. Rod-caught salmon and sea trout can never be sold, and licence holders must send an annual catch return even if they did not fish.
Wales: all salmon must be returned, on every river, including the Wye and Usk (NRW). Sea trout over 60cm must also go back, and the minimum size is 23cm (21cm in Gwynedd) (NRW size limits).
Scotland: catch and release is mandatory across Scotland until 31 March, and on rivers graded as poor conservation status (grade 3) by Scottish Ministers (Fisheries Management Scotland). Grades are reviewed, so check your river’s current grade with the Scottish Government.

Fishery rules can be stricter than the law, so read the permit as well.

Keep a released fish in the water and return it with as little injury and delay as possible. Radio-tracking on the River Eden found over 85% of released spring salmon could reasonably be expected to survive to spawn.

If you are unsure, put it back.

What the Latest Stock Figures Say About UK Salmon Runs

In 2024, anglers in England and Wales released 96% of the salmon they caught, the joint highest rate on record.

The same summary report puts the provisional 2024 rod catch at 5,930 salmon, the third lowest since 1988. Of those, 5,678 were released and 252 retained.

In Wales, NRW’s published stock assessment (2019) rated all salmon stocks At Risk or Probably at Risk, along with 29 of 33 principal sea trout rivers. In Scotland, Fisheries Management Scotland reports that over 95% of rod-caught salmon are now returned.

Smaller runs make the calendar less predictable. A river that once produced fish most weeks may now go quiet for long spells, so check its recent catch returns rather than relying on its reputation, and expect to release most of what you catch.

Frequently asked questions

When do salmon run in the UK?

Through much of the year. Multi-sea-winter spring fish arrive early, grilse mainly from June to August, and more fish move in autumn after rain. Timing varies by river, so see the calendar table above and check the fishery's catch returns.

What is a grilse?

A grilse is a salmon that has spent one winter at sea (1SW) before returning to its river. In England and Wales, grilse mainly enter rivers from June to August, making them the main summer run on many rivers.

When does the salmon season end?

It depends on the river. Most Welsh rivers close on 17 October, many rivers in northern England fish to 31 October, and several south west rivers close earlier. Some Scottish districts run later. See the season table above and check the byelaw, NRW or Scottish Government.

Can I keep a salmon in the UK?

Often not. England requires release before 16 June and many rivers are all-release, Wales requires every salmon to be returned, and Scotland requires release until 31 March and on grade 3 rivers. Check the fishery's own rules too.

What is a finnock?

A finnock is a sea trout that returns to the river in the same year it went to sea, according to the Environment Agency's Celtic Sea Trout Project.