[6] According to the United States Census Bureau, the city has a total area of 2.0 square miles (5.1 km2), all land.

The area lies in the western portions of the Texas Hill Country, a region of limestone outcrops and rolling terrain dotted with areas of live oaks (Quercus fusiformis) and juniper (Juniperus ashei) in the form of a woodland or savanna, alternating with a blend of various grasses and other shrubs and cacti.

Sonora's climate is subhumid and subtropical, though periods of long drought are not uncommon due to the proximity of deserts and steppes nearby, to the west.

Thunderstorms with heavy rainfall are most frequent during spring and fall months, though some lighter, steady precipitation and low clouds can occur during the winter, due in large part to frontal systems originating on the plains and prairies to the north.

Fall through spring months are often pleasant, though winter can experience brief periods of cold or cloudy weather.

[10] As of February 24, 2016 the mayor of Sonora was Wanda Shurley and the four council members were Doug Chandler, Todd Munn, Jeremy Dawson, and Terri Johnson.

On the night of April 2, 1901, William Carver, a member of Butch Cassidy's Wild Bunch, was shot and killed in Jack Owen's Bakery by Sheriff E.S.