This paper by Simon Leach (in Somerset Archaeology and Natural History, 2010) reports on first flowering dates (FFDs) of 339 vascular plant species in Somerset in 2008, 2009 and 2010, and compares them with those recorded by Walter Watson in the first half of the 20th century.
In 2020, Simon proposed a county-wide survey of FFDs during the spring COVID-19 lockdown, with members each recording dates in their local area. The results of this survey can be found in the SRPG Newsletter Issue 21 (page 7 onwards).
The survey was repeated in 2021, in a simplified form, as explained in this post. Simon has produced this report summarising the findings.