Quality made outdoor furniture is built to withstand the elements, but be careful when choosing your cushions.
The best patio cushion fabric is Sunbrella. Outdoor furniture-specific fabrics generally undergo a special chemical treatment to increase moisture resistance.
If needed, hose fabrics down weekly, or deep-clean with a mild soap and water.
Avoid detergents and hot water, which can compromise the protective materials.
Here in Colorado, I would also recommend furniture with legs to clear the height of snow, and covering your patio furniture in the winter and storing your cushions in a covered area.