The City of Greenfield is located in the heart of the Salinas Valley, formed by the Gabilan Mountains range to the east and the Santa Lucia Mountains range to the west. Greenfield is, approximately 135 miles south of San Francisco, 95 miles south of San Jose and 60 miles north of Paso Robles. According to the United States Census Bureau, the city has a total area of 2.1 square miles (5.4 km2), all of it land.
The climate for Greenfield is moderate with average temperatures around 50 degrees in winter and about 70 degrees in summer. High temperatures may reach the low 90s during mid-summer. Most rain falls between October and March; there are 14-20 inches of rain annually.