Records from South Kerry suggest the growing season for plants has been extended in recent decades.
Valentia Observatory and the National Botanic Gardens in Dublin have the most complete set of historical records on the timing of the main seasonal changes in plants.
The Central Statistics Office published Plant Phenology 2020, which shows annual seasonal changes in plants and animals, such as the flowering of plants, the emergence of insects and the migration of birds.
These growing season records are a useful proxy for temperature in the study of climate change, as many plants and animals are sensitive to variations in climate.
There are indications the beginning of leaf unfolding in trees may be happening earlier in spring, but there is wide variation between years.
The report found the length of the phenological season for Downy birch at Valentia varied from 168 days in 1979 to 236 days in 2014.
However, while the data suggests the growing season may be getting longer, the earliest date for the beginning of leaf unfolding at Valentia was on March 13th, 1975.
