 Huglin index

Pierre Huglin developed a bioclimatic heat index for vineyards, the Huglin heat sum index (or "after Huglin" respectively -warmth index or short Huglin index,) in which the temperature sum over the temperature threshold of 10 °C is calculated and then summed for all days from beginning of April to end of September.The calculation uses both the daily average temperatures and the maximum temperatures and slightly modifies the calculated total according to latitude.