The terrain of the municipality is gently sloping to undulating particularly the northern portion where in cultivated lands are located. Between the northern and southern fringes are areas moderately sloping to rolling land with some scattered steep hills.
The Mount Natib complex stretches from Dinalupihan-Hermosa area down to Balanga.
Mount Malasimbo is the most famous landmark of Dinalupihan. It is a cone-shaped mountain located at the northwestern portion of the municipality. It is also called the “Little Mount Mayon” of Central Luzon. Fortunately, it is not of volcanic origin.Mount Malasimbo has been embroiled in a boundary issue between Bataan and Zambales. A copy of a 1973 map prepared by the Philippine Coast and Geodetic Survey which was published under the authority of the Secretary of National Defense showed that the 400-meter high mountain is part of the Zambales mountain ranges and lies inside the provincial boundary of Zambales. In fact, it is part of the town of Subic, not Olongapo City. In 2004, however, the Ortho-Geographic Information System Center of the Subic Bay Metropolitan Authority released a document showing that Mount Malasimbo is already outside the 400-meter bounds of Zambales and presently within the municipal boundary of Dinalupihan, Batyawan Mountain, a neighboring mound, is also inside Dinalupihan territory.
There are six major rivers in Dinalupihan:Balsic River, Caulaman-Gumain River, Layac River, Almacen River, Dansong Pare and Tubo-tubo River. Five of these rivers well from the Zambales mountain ranges while the Almacen River originates from the Mount Sta. Rosa and Mount Sta. Rita Watershed. But all six rivers run through the length and width of Dinalupihan and end up in Manila Bay. These rivers also branch out to smaller creeks which supply the agricultural water requirement of the municipality. The connecting Caulaman-Gumain River and Balsic River irrigate the agricultural lands of San Simon, Pagalanggang , New San Jose, Poblacion, Pentor, Sta. Isabel and Daang Bago. The Almacen River-Layac River, on the other hand, supplies irrigation water to Bangal, Roosevelt, San Pablo, Pinulot, Happy Valley, Naparing, Colo, Magsaysay, San Benito, Luacan and Layac. Dansong Pare River traverses along the Payangan and San Pablo areas. Tubo-tubo River cuts across Tubo-tubo and Lourdes. There are other creeks criss-crossing the length and width of Dinalupihan which make the land very fertile and best suited to crops production. Besides agriculture, people derive livelihood from these rivers filled with various freshwater fish. Almacen River is still the habitat of several varieties of edible fish. These rivers, however, also pose danger to people especially during rainy seasons. Because of the non-stop denudation of our forests, Layac and Balsic Rivers easily overflow and engulf many parts of Dinalupihan under water. More river control projects and dredging of silted tributaries have to be implemented to prevent further loss of lives and properties.
B. Climatic Condition and Rainfall
Dinalupihan enjoys a generally pleasant climate which belongs to the first type of climate in the Philippines. Average temperature is 80% or 760 C. The coldest months are December, January and February, while the hottest months are April and May. Humidity ranges from 75% to 80%. There are two distinct seasons, the Dry Season from March to June, and the Rainy Season from July to October. Approximate rainfall is 98.9 inches.
C. Soil Types
The soil cover of Dinalupihan is generally classified into five (5) major physio-geographic grouping namely; La Paz silt loam, La Paz fine sand, Culis Loam. Antipolo soil undifferentiated and Antipolo clay.
The town of Dinalupihan has a very limited mineral resources. Only non-metallic minerals like gravel, boulders, earth and clay materials can be found in the area. Boulders and gravels are commonly used as construction materials while earth clay is used as cooking stove in the farm houses.