Our garden is swarming with wasps

As of yesterday, our garden has been abuzz with wasps (a surprising amount). They've been out even more today. It is very sunny, and 82° F. at the moment (the forecast says mostly cloudy, but it looks clear and sunny to me). There are some white clouds (such as you might see in summer), though. I don't remember this many wasps last spring (although we usually have a lot of wasps).

The wasps aren't the same kind mentioned in this post (I'm pretty sure they're not yellow jackets). I got some pictures (although it took a little while to find some that weren't flying; fortunately, they like to use my giant tomato cage for something or other—probably for getting nest supplies).