Where to travel to in early June (good weather)?

akaoct2005

My husband gets a very rare week off of work the 2nd week of June and we'd like to take a vacation with our DDs (3 and 1).  We would love to go somewhere with warm weather (beach/pool preferably).  We would also prefer to stay in the US, but will consider somewhere close (Mexico).  So, where should we go?  Not too crazy expensive, kid friendly...

 

Oh, we're in Southern California...

 

Thanks!