Duncanville is located in the southwest corner of Dallas County, and approximately 15 miles south of downtown Dallas just off Interstate 20.

Located less than five minutes from Interstate 35, Duncanville is approximately 100 miles south of the Texas/Oklahoma border and approximately 200 miles north of Austin. According to the United States Census Bureau, the city has a total land area of 11.22 square miles and the elevation is approximately 700 feet above sea level.

Duncanville and Dallas County are classified as having a humid subtropical climate, and have a wide annual temperature range. Precipitation is also widely variant, ranging anywhere from 20 inches to 50 inches per year (averaging around 36 inches). Winters are usually mild with the average annual snowfall being 2.5 inches.

Average Area Temperatures (°F)
Month High Low
Source: National Weather Service Southern Region
January 55.5 35.3
February 61.3 39.9
March 69.4 47.4
April 76.7 54.9
May 83.8 63.6
June 91.4 71.1
July 95.9 75.0
August 95.5 74.5
September 88.8 67.7
October 78.9 57.1
November 66.2 46.0
December 57.6 37.8