I did get the front yard mowed before we had a shower. I felt a drop or two of rain while I was mowing, but it didn't start raining until 45 minutes later, and then briefly.
And luckily, because a storm was coming, there was cloud cover and slightly cooler, breezier air so it wasn't quite so hot. I prefer to mow in the early morning, but we've had so many showers lately that I couldn't chance another weekend of not getting it done.