According to the United States Census Bureau, the city has a total area of 1.44 square miles (3.73 km2), all of it land.
The city is south of Medford and north of Talent and Ashland along Interstate 5 and Oregon Route 99. This is toward the southern end of the Rogue River Valley, near the Siskiyou Mountains and the border with California.
Coleman Creek, a tributary of Bear Creek, joins the larger stream at Phoenix. The Bear Creek Greenway, a biking and hiking trail connecting Ashland, Talent, Medford, and Central Point along Bear Creek, also passes through Phoenix.
This region experiences hot and dry summers, and cool and wet winters. According to the Köppen Climate Classification system, Phoenix has a hot-summer Mediterranean climate, abbreviated “Csb” on climate maps.
Phoenix’s record high temperature is 109 °F (43 °C) on July 20, 1946 and August 8, 1981, and the record low temperature is −8 °F (−22 °C) on December 9, 1972.