Coyote Point park is one of the best places to take kids in San Mateo. It's lovely year round, with lots of picnic tables, views and open space for playing. The park also has walking and biking trails throughout, and there are various habitats in the park. Part of it is a forest, then there is the marina with bay views, and there are beach areas where the boats go out. I love to just bring a book in the middle of the day and ride my bike here for a soothing respite. This is one of the things I love about the bay area!