Many vegetables do extremely well in "cooler temps", provided you take the time to shelter them from frost and other harsh elements. A Hoop House is a easy way to provide higher temps for your crops and keep them safe from frost, heavy rain and gusty winds!
You can extend the growing season in your own home vegetable garden, by building custom and inexpensive "hoop houses" over your existing raised beds. Once constructed, you'll provide higher temps for your crops and keep them safe from frost, heavy rain and gusty wind.
Here's a video that shows you how to construct your own "Hoop House":
Another option you have is to purchase a plastic greenhouse (like the one pictured at the top of the page), and place it directly over your raised bed. They come in all sizes, are very affordable, and will last many years if taken care of.