According to the United States Census Bureau, the township has a total area of 54.2 square miles, of which, 53.1 square miles of it is land and 1.0 square miles of it is water.
Demographics
As of the census of 2000, there were 11,495 people, 3,973 households, and 3,031 families residing in the township. The population density was 216.3 people per square mile. There were 6,021 housing units at an average density of 113.3/sq mi. The racial makeup of the township was 85.24% White, 7.66% African American, 0.22% Native American, 1.31% Asian, 0.01% Pacific Islander, 3.18% from other races, and 2.38% from two or more races. Hispanic or Latino of any race were 8.61% of the population. There were 3,973 households, out of which 42.8% had children under the age of 18 living with them, 63.4% were married couples living together, 7.9% had a female householder with no husband present, and 23.7% were non-families. 17.6% of all households were made up of individuals, and 5.5% had someone living alone who was 65 years of age or older. The average household size was 2.89 and the average family size was 3.29. In the township the population was spread out, with 30.9% under the age of 18, 6.1% from 18 to 24, 32.3% from 25 to 44, 21.8% from 45 to 64, and 9.0% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 102.6 males. For every 100 females age 18 and over, there were 98.9 males. The median income for a household in the township was $50,435, and the median income for a family was $54,821. Males had a median income of $40,852 versus $27,868 for females. The per capita income for the township was $20,235. About 2.8% of families and 4.5% of the population were below the poverty line, including 4.8% of those under age 18 and 6.1% of those age 65 or over.
Climate
According to the Trewartha climate classification system, Middle Smithfield Township has a Temperate Continental climate with warm summers, cold winters and year-around precipitation. Dcbo climates are characterized by at least one month having an average mean temperature ≤, four to seven months with an average mean temperature ≥, all months with an average mean temperature < and no significant precipitation difference between seasons. Although most summer days are comfortably humid in Middle Smithfield Township, episodes of heat and high humidity can occur with heat index values >. Since 1981, the highest air temperature was on 07/22/2011, and the highest daily average mean dew point was on 08/28/2018. July is the peak month for thunderstorm activity which correlates with the average warmest month of the year. The average wettest month is September which correlates with tropical storm remnants during the peak of the Atlantic hurricane season. Since 1981, the wettest calendar day was 5.87 inches on 10/08/2005. During the winter months, the plant hardiness zone is 6a with an average annual extreme minimum air temperature of. Since 1981, the coldest air temperature was on 01/21/1994. Episodes of extreme cold and wind can occur with wind chill values <. The average snowiest month is January which correlates with the average coldest month of the year. Ice storms and large snowstorms depositing ≥ 12 inches of snow occur once every couple of years, particularly during nor’easters from December through March.
Ecology
According to the A. W. Kuchler U.S. potential natural vegetation types, Middle Smithfield Township would have a dominant vegetation type of Appalachian Oak with a dominant vegetation form of Eastern Hardwood Forest. The peak spring bloom typically occurs in late-April and peak fall color usually occurs in mid-October. The plant hardiness zone is 6a with an average annual extreme minimum air temperature of.
