[4] The population was 2,782 at the 2020 census, making Colfax the second largest city in Whitman County behind Pullman.

[5] It is situated amidst wheat-covered hills in a valley at the confluence of the north and south forks of the Palouse River.

The honor ultimately fell to nearby Pullman, fifteen miles (25 km) southeast.

Colfax is located in southeastern Washington and the nearest cities are Spokane, Pullman, Moscow, and Lewiston/Clarkston.

The area is geologically interesting, lying in the midst of the fertile Palouse country in the middle of the Columbia River Plateau, with the Rocky Mountains to the east, the Channeled Scablands to the west, and the Snake River to the south.

According to the United States Census Bureau, the city has a total area of 3.79 square miles (9.82 km2), all of it land.

[11] The Palouse River, confined for flood control to a concrete bed that reduces it to an eighteen-inch-wide stream during the dry season, runs through the middle of town, parallel to Main Street.

Colfax has a four-season continental climate (Köppen Dsb), with hot, dry summers, cold winters, and a rainy season that generally runs from autumn til spring.

This climate, together with the deep, rich Palouse topsoil, makes for near-ideal wheat growing conditions.

Among the town's other amenities are Leonard Jennings Elementary School, Colfax High School, Whitman Community Hospital, multiple retirement facilities (Hill-Ray Plaza, Whitman Nursing Home, and The Courtyard), Paul's Place Assisted Living, eleven city parks, a skateboard park, a swimming pool and a public library.

The median age was 41 years, well above the national average of 35.3—possibly due to the presence of several retirement communities.

The city is infamous for speed traps, with a 25 miles per hour (40 km/h) speed limit on US 195 within city limits, and increases enforcement during Washington State University events, including football games.