Before revision: The essential information needed to calculate this index is: the humidity of the air at the beginning of the afternoon (when it has its lowest value); the temperature in the middle of the afternoon (when it has its highest value); the precipitations during 24h (from noon to noon); the maximum speed of the average wind.
After revision: The essential information needed to calculate this index is: the humidity of the air at the beginning of the afternoon (when it has its lowest value); the temperature in the middle of the afternoon (when it has its highest value); the 24-hour total precipitation (from noon to noon); the maximum speed of the average wind.