As it sounds like you already know, the temperatures throughout San Diego County can vary widely.
If you go to my website, www.GreaterGoodRealty.com and click on the "Lifestyle" tab along the top, you can search each neighborhood and view the average weather temperatures by month, average rainfall, and much more.
It also give you school district information, demographics, average income, and more.
Hope this helps.
By the way, I am the co-founder of Greater Good Realty. In addition to providing valuable information about the San Diego real estate market, my company donates 10% of our commissions to local charities and non-profit organizations throughout San Diego.
We hope to make a difference for those in our neighborhoods!
Greater Good Realty