Sisters is a city in Deschutes County, Oregon, United States.[6] According to the United States Census Bureau, the city has a total area of 1.87 square miles (4.84 km2), all land.On Cascade Avenue, there is a lot of pedestrian traffic and many specialty stores and galleries.East of Sisters the two highways split, with 126 heading to Redmond and 20 going to Bend.This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F (22.0 °C).The Sisters Ranger District Office is located at Pine Street and Highway 20.[18] Hiking, biking and horse riding trails go from the city limits into the Three Sisters Wilderness.