After Morgan dies, Wyatt runs into the street and mourns his brothers death by yelling and crying. It is raining on the street only where he is. Looking down the street everything is still dry.
Yup, I noticed that one the first time I saw the movie. Not only is the dirt it dry 20 feet from where he's standing, but as the camera pans up, you can also see that the buildings and other items in the background are dry as well.
What's most obvious though is that you can see that all of the water (probably from multiple re-takes) has run down the middle of the street and formed a big puddle about 50 feet away. You can clearly see bright light reflecting off of the mud as well as the dry ground around it.
This is a common mistake in movies with rain. As most people know, they use a crane to lift a rainmaking machine overhead, but it will usually only cover a small area (maybe a 50-100 foot square). Sharp-eyed movie watchers will see very few movies with real rain.