"Short rains season is October and November"
Translation:Vuli ni mwezi wa kumi na mwezi wa kumi na moja
So "vulil means short rain season and can mean autumn but if meaning autumn (which doesnt really exist in the tropics) "msimu wa vuli" is better?
Or you could specifiy "vuli la Ulaya" (or explain it if the person should not be familiar with European weather - the first time). I'm usually a bit sceptical to just assume it will be clear when transferring (between continents or cultures).