For example, if for a given location, on the 25th of July at 13:00 UTC the WSI is 85 for a temperature of 42 Coulomb , this means that the temperature was inferior to 42 °C in 85% of the time in the past, on the same place, on the 25th of July at 13:00 UTC (and superior to 42 °C in 15% of the time on the same place, day and hour).