Grayling · Thymallus thymallus

Grayling in England's Rivers

The largest recorded measurement is 60 cm (23.6 in), from Harbrook,Ramsbury in River Kennet on 17 November 2005.

Median length: 18.5 cm (7.3 in)
Fish measured: 40,729
Named waterways: 261
Latest observation: 27 Jul 2026

Direct individual measurements

Largest grayling by waterway

Ranked by the largest individual measured in EA surveys. The sample size shows how many valid length measurements underpin each waterway's figures.

Rank	River or waterway	Largest	Median	Measured	Measured at
1	River KennetSouth East	60 cm (23.6 in)	21.2 cm (8.3 in)	1,036	17 Nov 2005Harbrook,Ramsbury
2	River GwashAnglian	55.6 cm (21.9 in)	21.6 cm (8.5 in)	491	24 Jun 2013Belmesthorpe Meadow
3	River ItchenSouth East	48.5 cm (19.1 in)	19.9 cm (7.8 in)	1,333	2 Sept 2002Swimming Pool, Winchester
4	River Derwent (Yorkshire)Yorkshire and North East	47.6 cm (18.7 in)	18.1 cm (7.1 in)	684	16 Jul 2015Howsham DERCORS8
5	River AireYorkshire and North East	46.4 cm (18.3 in)	20.2 cm (8 in)	531	20 Aug 1998Gargrave STW
6	River HullYorkshire and North East	46.3 cm (18.2 in)	15.1 cm (5.9 in)	1,949	23 Oct 2009West Beck Downstream Copper Hall Weir.
7	River AllenSouth West	45.8 cm (18 in)	20.3 cm (8 in)	517	26 Jul 2001Downstream Fitches Bridge
8	River LambournSouth East	45.2 cm (17.8 in)	19.8 cm (7.8 in)	1,407	20 Oct 2000Easton Lodge
9	River WindrushSouth East	45 cm (17.7 in)	22.1 cm (8.7 in)	240	22 Apr 2005Lower Upton Farm
10	River WharfeYorkshire and North East	44.8 cm (17.6 in)	10.8 cm (4.3 in)	4,165	30 Jul 2003Pool Mill

Equal maximum lengths are ordered by sample size. Measurements are shown as recorded and are not converted into estimated weights.

40,729 fish measured

Measured grayling lengths

The median divides the measured sample in half. This distribution describes surveyed fish, not every grayling living in England.

0–19 mm

20–39 mm

40–59 mm

261

60–79 mm

1868

80–99 mm

5328

100–119 mm

5081

120–139 mm

3573

140–159 mm

1715

160–179 mm

1681

180–199 mm

3347

200–219 mm

4123

220–239 mm

3719

240–259 mm

2549

260–279 mm

2265

280–299 mm

2024

300–319 mm

1258

320–339 mm

802

340–359 mm

502

360–379 mm

274

380–399 mm

183

400–419 mm

420–439 mm

440–459 mm

460–479 mm

480–499 mm

540–559 mm

600–619 mm

Only positive individual lengths that pass RiverFish's general measurement checks are included. Each bar covers a 20 mm range.

Latest EA evidence

Latest grayling observations

The ten most recent survey visits that recorded grayling in named waterways.

Date	River or waterway	Survey location	Fish recorded
27 Jul 2026	River Swale	Great Langton DS of midbar	1
23 Jul 2026	River Lee	Amwell Loop	19
8 Jul 2026	River Main Ottery	Penrose	3
30 Jun 2026	River Aire	Hirstwood, u/s Bradford Beck	1
17 Jun 2026	River Dearne	Stairfoot	4
16 Jun 2026	River Western Rother	Terwick Mill	11
2 Jun 2026	Swanside Beck	Smithies Bridge (A59)	1
7 Apr 2026	River Anker	Leathermill	1
1 Apr 2026	River Nar	Bone Mill	2
13 Nov 2025	River Witham	Queen Elizabeth Park	12

A survey record confirms grayling at that place and time. It does not show present-day abundance or fishing access.

3,736 positive survey visits

Survey distribution

EA surveys recorded grayling at 1,152 locations across 261 named waterways represented on RiverFish.

Region	Waterways	Locations	Survey visits	Latest record
Yorkshire and North East	65	354	1,398	27 Jul 2026
Midlands	60	248	715	7 Apr 2026
South West	53	203	673	8 Jul 2026
South East	42	221	641	23 Jul 2026
North West	27	67	152	2 Jun 2026
Anglian	14	59	157	1 Apr 2026

150 detailed pages

Grayling by river

Open any river-specific page for its measured lengths, largest surveyed individuals, locations and observation history.

Anglian 9 pages

Great Eau FMU5 locations · latest 2022 Great Eau Riffles9 locations · latest 1995 River Chater3 locations · latest 1996 River Gwash12 locations · latest 2023 River Nar4 locations · latest 2026 River Nene4 locations · latest 2001 River US Lt Ouse3 locations · latest 1996 River Welland2 locations · latest 2013 River Witham10 locations · latest 2025

Midlands 32 pages

North West 11 pages

Brunstock Beck2 locations · latest 2019 Pendle Water3 locations · latest 2023 River Bollin4 locations · latest 2025 River Calder3 locations · latest 2025 River Dane2 locations · latest 2024 River Etherow3 locations · latest 2025 River Goyt17 locations · latest 2025 River Hodder3 locations · latest 2025 River Peover Eye4 locations · latest 2024 River Petteril3 locations · latest 2018 River Ribble4 locations · latest 2018

South East 25 pages

South West 32 pages

Yorkshire and North East 41 pages

How to read this page

Survey measurements, not angling records

Environment Agency surveys are designed to monitor fish populations. Their largest measurement is not equivalent to a verified rod-and-line record, and the survey sample does not include every river or every grayling.

Waterway groups with administrative or mixed-river labels are excluded from the headline national totals and rankings. Their eligible river-specific pages remain available in the directory so no published destination is hidden.

The fish records use the Environment Agency source snapshot dated 10 August 2026.

How RiverFish handles the data →