If you can stand the heat and dryness on the hikes in/out, you can find water year round at a handful of camps and along a handful of trails in the southern Los Padres. May just have to put up with longer, dry stretches in between water sources though.
Around the Sespe Wilderness, Sespe Creek will at least have some pools year round. If you head in deep (toward Alder Creek) it will probably even still be running into the summer. The Fishbowls will probably have water for a while longer but I wouldn't expect there to be much, if any, water on the hike in/out. Some of the camps along Piedra Blanca Creek (Twin Forks and Piedra Blanca) should have water into the summer. Lower Agua Blanca Creek (heading upstream from Piru) will have water up until the Narrows or so; beyond that will dry up sometime soon. Lower Piru Creek will also have water but it could get kinda' yucky; I prefer to filter from tributaries in this area. Maybe Beartrap Camp/Creek too on the Gene Marshall Trail Might also try Chorro Grande Spring. There's a few other camps with springs that will probably be pretty reliable into the summer (The Pines on Horn Cyn Trail, Valley View Camp on the Pratt Trail, etc.).
Heading a little farther north into the Dick Smith and San Rafael Wildernesses, you should be able to find water into the summer along upper Manzana Creek, Indian Creek, Santa Cruz Creek, and the upper Sisquoc. Again, some of the springs around should prove pretty reliable: Mission Pine Springs, McKinley Springs, Chokecherry Springs, Big Pine Springs.
This year will be tough, especially as we get later into the summer. We didn't get much rain last year and some of the creeks that typically have at least some water year round were bone dry last summer. With hardly any rain again this year, I fear the creeks will be even less reliable. The various springs, if they're good ones (like the ones I mostly listed), should run year round to some extent.
There's always Big Sur a little farther up north. Tends to be a little more temperate and have more reliable water into the summer in my experience.