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Spring index
The spring index shows how early or late the onset of vegetation development has been each year compared to the long-term average.
The spring index shows how early or late the onset of vegetation development has been each year compared to the long-term average.
The index is always updated at the end of May. Ten different phenological phases are taken into account for the purpose of determining the spring index:
These observations come from the MeteoSwiss phenological monitoring network.
Around 80 stations with sufficiently long measurement series are taken into account in the calculation of the spring index. The onset of spring vegetation growth is heavily dependent on temperature.