You were on the right track. You only needed the hour columm element, which in the source code is div.weathertable__row:
{"_id":"windfinder-tarifa","startUrl":["https://www.windfinder.com/forecast/tarifa_stadtstrand"],"selectors":[{"id":"forecastTable","multiple":false,"parentSelectors":["_root"],"selector":"div#fc-table","type":"SelectorElement"},{"id":"weatherTableContainer","multiple":true,"parentSelectors":["forecastTable"],"selector":"div.weathertable-container","type":"SelectorElement"},{"id":"weatherTable","multiple":true,"parentSelectors":["weatherTableContainer"],"selector":"div.weathertable","type":"SelectorElement"},{"id":"date","multiple":false,"parentSelectors":["weatherTable"],"regex":"","selector":"h3","type":"SelectorText"},{"id":"time","multiple":false,"parentSelectors":["hour column"],"regex":"","selector":"div.data-time","type":"SelectorText"},{"id":"speed","multiple":false,"parentSelectors":["hour column"],"regex":"","selector":"div.speed","type":"SelectorText"},{"id":"gusts","multiple":false,"parentSelectors":["hour column"],"regex":"","selector":"div.data-gusts","type":"SelectorText"},{"id":"hour column","multiple":true,"parentSelectors":["weatherTable"],"selector":"div.weathertable__row","type":"SelectorElement"}]}