"The short rains season is in October and November"
Translation:Vuli ni mwezi wa kumi na mwezi wa kumi na moja
This on-line dictionary (TUKI) should reduce your search time to less than 20 seconds:
(But, note that the letter "S" in English-Swahili returns an empty page).
vuli nm [i-/zi-] short rainy season: Mvua za ~ short rains.
PS: Google translate is terrible and utterly unreliable for Swahili.