Porterville, CA (93257) Today. Partly cloudy. A stray shower or thunderstorm is possible. High 81F. Winds SSW at 5 to 10 mph.. Tonight. Mainly clear skies. A stray shower or thunderstorm is possible. Low 53F. Winds S at 10 to 15 mph. Updated: May 25, 2019 @ 1:36 am