Kirby, Texas is a small town located in Bexar County, in the southern part of the state. The climate in Kirby is considered humid subtropical, characterized by hot and humid summers and mild winters. Summers are typically long and hot, with temperatures often exceeding 90°F (32°C), while winters are short and mild, with average temperatures ranging from 40°F (4°C) to 60°F (15°C).

Hydrologically, Kirby is situated in the San Antonio River Basin. The San Antonio River runs nearby, offering residents and visitors opportunities for outdoor activities such as canoeing, kayaking, and fishing. The river is also a popular spot for birdwatching as it attracts various species of waterfowl.

In addition to the river, Kirby has several parks and green spaces, including Friendship Park, which features a playground, walking trails, and picnic areas. The town also has a community pool for residents to enjoy during the summer months.

Overall, Kirby, Texas provides a pleasant climate, access to the San Antonio River, and various outdoor recreational opportunities for its residents and visitors.