During British Science Week this year, we asked the general public to help calculate the speed at which spring moved across the UK with Nature’s Calendar. The results were released on 11 June on BBC Springwatch.

The movement of spring across the UK appears to be speeding up according to analysis of over 20,000 public records in collaboration between the Woodland Trust, British Science Association and BBC Springwatch.

Records of seven spring events submitted to Nature’s Calendar over the last four months have been analysed by Professor Tim Sparks from Coventry University to track the rate of progress up the country.

On Springwatch we revealed the average speed of the passage of spring this year to be roughly 1.9mph, taking nearly three weeks to cover the length of the country from south to north. An average of 1.2mph was recorded using data between 1891 and 1947 and 1.8mph using data recorded between 1998 and 2014.

Speed of travel from south to north in 2015 (appearance of event):

  • Ladybird – 6.5mph
  • Hawthorn leafing – 6.3mph
  • Swallows arriving – 2.4mph
  • Hawthorn flowering – 1.9mph
  • Orange tip butterfly – 1.4mph
  • Oak first leafing – 1.3mph
  • Frogspawn – 1mph

The research also found that the passage of spring is not directly south to north but is aligned southwest to northeast, as are early spring temperatures.

Professor Sparks said, “Some of these events appear to be more reliable than others in determining the speed of the progress of spring. Comparison with previous years does suggest that spring may be moving faster now than it did in the past.”

Katherine Mathieson, Director of Programmes at the British Science Association, said “It’s incredibly important that we understand the timing of the seasons, to help identify changes in the climate which could be having a detrimental effect on wildlife. A huge thank you to everyone who took part in the study!”


Take part in Nature’s Calendar,  the longest written biological record of its kind, with information dating back to 1736 and is a powerful tool in assessing the impact of climate change.