@Andy_F In fact the 1-hour precipitations stand for the last 3 hours, as shown by the weather picker and said in the FAQ. https://community.windy.com/topic/3361/description-of-weather-overlays?sort=oldest_to_newest You can check it hour by hour on the Rain layer. So if you accumulate all precipitation in the 1-hour table you get an excessive total. I must admit it is confusing. I think the accumulation of 3-hour rain is more correct. @Suty Please could you confirm my guess.