Robstown, located in Nueces County, Texas, experiences a humid subtropical climate. Summers are hot and humid with temperatures averaging in the mid-90s°F (35°C), while winters are mild with temperatures ranging from the mid-40s°F (7°C) to the mid-60s°F (18°C). Rainfall is fairly evenly distributed throughout the year, with an annual average of around 30 inches (76 cm).

Robstown is situated within the Coastal Bend region, characterized by a diverse hydrology. The city lies near the Nueces River and is part of the Nueces River Basin, which provides a vital water source for the community. Groundwater is also an important resource, with several aquifers, including the Gulf Coast Aquifer, supplying water to the area.

Outdoor enthusiasts in Robstown can enjoy a variety of recreational activities. The nearby Corpus Christi Bay offers opportunities for fishing, boating, and water sports. Nature lovers can explore the beautiful Oso Bay Wetlands Preserve & Learning Center, which provides educational programs and trails for bird-watching and hiking. Additionally, the city has numerous parks and sports facilities that cater to outdoor activities like soccer, baseball, and tennis. Overall, Robstown offers a pleasant climate, ample water resources, and outdoor recreation options for residents and visitors alike.