The municipality of Sta. Teresita is situated on the north-eastern part of the province. It lies on a geographical coordinate of 121 degrees 53 minutes east longitude and18 degrees 15 minutes north latitude. It is approximately 118 kilometers from the Regional Center. It is bounded on the north by municipalities of Buguey and Gonzaga, and on the east and southeast by the municipality
of Buguey and on the south by the municipality of Lallo.
The municipality of Sta. Teresita has a total land area of 16,698.93 hectares that shares 1.75% of the provincial land territory. Including disputed areas from the boundaries of Buguey and Gonzaga the municipality has an area of 16,727.0698 hectares. It is politically subdivided into 13 barangays,
composed of 4 urban barangays and 9 rural barangays.
Long stretch of mountain ranges characterizes the municipal topography.
These ranges are in the southern part of the town. On the Northern part are agricultural, swamps, and residential areas. The terrain varies from plain to gently sloping to undulating to rolling, rolling to hilly to mountainous as it goes from North to South.
There are five (5) soil series identified by the Department of Agriculture, Soil Management Bureau, within the municipality. These soil series are Tagulod, Alaminos, Toran, Quingua and Bolinao
series. Tagulod series is best suited for lowland rice. This series is usually found on a relief of level to nearly level land. Toran series are usually found on level relief and they are best suited for vegetables production and fishpond. Quingua series are usually found along the riverbanks and usually flooded. Alaminos and Bolinao series are mountain soils. These series are usually found on undulating to rolling terrain. They are suited for upland crops, orchard and pasture.
The municipality of Sta. Teresita falls under the fourth type of climate (type IV) in the Philippines as identified by
Coronas Climate Classification. Wet season falls on the month of October, November and December and dry season during the rest of the year. Rainfall distribution is not yet very pronounced and is more or less evenly distributed throughout the year.