Sterna paradisaea – MOR-WENNOL Y GOGLEDD – Passage migrant. Not recorded from December to March
Previous records are summarised in Arctic Tern 1994
| Year | First | Last | Notes |
| 1993 | 4 May | 15 September | |
| 1994 | 18 April | 1 November | |
| 1995 | 14 May | 18 October | |
| 1996 | 24 April | 25 October | |
| 1997 | 22 October | No spring records | |
| 1998 | 25 October | No spring records | |
| 1999 | 6 November | No spring records | |
| 2000 | 8 May | 17 October | |
| 2001 | 18 April | 31 October | |
| 2002 | 9 October | No spring records | |
| 2003 | 29 April | 17 October | |
| 2004 | 25 October | No spring records | |
| 2005 | 6 November | No spring records | |
| 2006 | 21 October | No spring records | |
| 2007 | 25 June | 30 October | |
| 2008 | 19 April | 1 October | |
| 2009 | 2 November | No spring records | |
| 2010 | 19 October | No spring records | |
| 2011 | 19 October | No spring records | |
| 2012 | 14 October | No spring records | |
| 2013 | 19 April | 3 November | |
| 2014 | 21 October | No spring records | |
| 2015 | 16 September | No spring records | |
| 2016 | 18 October | No spring records | |
| 2017 | 27 October | No spring records | |
| 2018 | 18 April | 21 September | |
| 2019 | 1 October | ||
| 2020 | 25 September | No spring records |
