Extreme weather really is a problem here. We don't get the coldest winters but we get them cold enough, and unfortunately not consistantly cold, that it keeps most produce from growing quite right.
Head south and you have the humidity and the gulf keeping things in check. Go north and you have winters that stay cold and don't jump to the mid eighties all of the sudden convincing your broccoli and lettuce to bolt. Head east even and you start to hit a little more humidity. By the time you reach Louisiana green is a major color in the landscape.
Couple that with the grey blotch you can see in images from space, the grand mass of concrete which keeps this area nearly 5 degrees hotter than surrounding areas and there goes your moisture.
I was watching the weather a few weeks ago when we were supposed to have rain and you could see the clouds and rain part in the middle as it reached the metroplex. There was so little humidity and so much heat that it absorbed the clouds before they could do much of anything.
Yet here I am still. What can I say, I live really close to work.