Phenology Forms

Find the 2025 Phenology form here

Phenology Reports

The results and reports

a)  CNHS collected Phenology data for several years at the beginning of this century. These have been combined
         with this years data and analyzed in a standard manner.
b)  Given the methodology by which CNHS collect this data we will need significantly more data points before
        any statistical analysis yields a significant result.
c)   However, the real value is in the creation of a significant set of data that illustrates changes to species over
         time.

What impacts Phenology results ?
1)  Numerous studies into changes in phenological records suggest that it is temperature that is the primary
       cause (Sparks,Jeffree & Jeffree 2008, Menzel 2006, etc).
2)  Using Met office data for Southern England during the recording period :
          i)   The warmest springs (average of Feb, Mar, Apr) were 2007, 2011, 2017.
         ii)   The coolest springs were 2006, 2010.
         iii)  2009 had a relatively cold Feb and a warm Mar/Apr

Health Warning … the data collection method introduces significant variability into the results … and
therefore any comments on the results are pure speculation.

2024 CNHS Phenology report and figures click here

2023 CNHS Phenology report and figures click here

2022 CNHS Phenology Report and figures click here

2021 CNHS Phenology Report and figures click here

2020 CNHS Phenology Report and figures click here

2019 CNHS Phenology Report and figures click here

2018 CNHS Phenology Report and figures click here

2017 CNHS Phenology report and figures, including prior years, click here