The regions around Locarno, Scottoceneri and Mendrisiotto were particularly impacted according to Viasuisse, the road traffic information agency.
MeteoSwiss, the national weather office, issued a level three weather alert (on a scale of one to five) for the canton, warning that heavy rain would continue on Monday until midnight.
Fire fighters were called to deal with flooding, downed trees and blocked roads in 250 locations, according to local media reports.
In the municipalities of Arogno and Caprino, officials informed residents that tap water was no longer potable because of excessive turbidity in its water supply, the Corriere del Ticino newspaper reported on Sunday.
Numerous rivers and streams spilled over their banks while overcharged culverts flooded roads, the newspaper said.
Italian-language national broadcaster RSI reported that 100 millimetres of rain fell in a 12-hour period in the Locarno region between Saturday and Sunday.
Other regions of Switzerland have also experienced challenging weather conditions, including the canton of Valais where MeteoSwiss issued a warning of winds between 90 and 100 kilometres an hour above the 2,400-metre level for late Sunday.
A Foehn wind, meanwhile brought unseasonably warm conditions to the Rhine and Reuss valleys over the weekend.
Communities such as Füelen in the canton of Uri and Bad Ragaz in the canton of Saint Gallen registered temperatures of more than 25 degrees on Saturday.
Winds approaching 100 kilometres an hour were recorded the same day in the Bernese Oberland and Vaud Alps, the ATS news agency reported.