Phenological recording has been happening at the Royal Botanic Garden Edinburgh for a long time.
One of the annual outputs is the Edinburgh Spring Index, which monitors the first flowering events of 25 taxa and plots them against an arbitrarily chosen standard of 2002. Since not all plants flower by the arrival of the astronomical day of spring (normally 21 March), the preliminary index is re-calculated every year using the plants that have flowered. A consolidated index appears at the end of the year. Past consolidated indices have been:
2002 0 days (by definition)
2003 early by 1 day
2004 early by 10 days
2005 early by 6 days
2006 late by 6 days
2007 early by 8 days
2008 early by 7 days
2009 neither early nor late (0 days)
2010 late by 12 days
2011 late by 4 days
2012 early by 8 days
For 2013 the consolidated spring index was 6 days late, with comparitors shown on a pdf file here.
A 3D graph of the consolidated Edinburgh Spring Index since 2002 can be seen here.
file updated on 12 November 2013