Cyprus or the Canaries would fit the bill. Temperatures will be around the low twenties. Flying time about 4 hours. Closer to home will generally mean lower temperatures, although you could get lucky in Spain/Portugal.
http://www.tripadvisor.co.uk/ListForums-...
Obviously the cost of the holiday must be a concern for you.
I would suggest Spain, Portugal or Italy as it is cheaper. Obviously the weather cannot be guaranteed 100% but even right this minute and this hour it is 22deg C here on the Costa.
If your funds allow it then try something different like Dutch Antilles St Maarten. It will be a holiday you will never forget. The setting is amazing so both you and the kids will love it. However it can be very expensive getting there, yet staying there is relatively cheap.
It really depends on your budget.
Canary Islands, Cape Verde Islands, Cyprus, South Greek Islands like Crete good and warm, not too hot.
California's perfect in the south anyways
Not the UK, that's for sure.
