The 2016 update has been quite bad for my yard. Early in the season, I tried using the flex schedule. As the temperature started heating up, however, I found that my yard was drying out. Worse, when I looked at the schedule I found that it wasn't planning to water my yard for another 14 days. So, I went off the flexible schedule and started using fixed schedules.
The fixed schedules mostly work. However, I find that they cause the system to skip on days that just don't make sense. I live in New Mexico and we've had very little rain this year. Though we've had a couple good rain days, the rain is mostly spotty. The temperatures have been in the 100 F range and this is further drying out the yards. None-the-less, this morning, the Rachio is still skipping days unexpectedly. This morning, I noticed that it had emailed me that it was skipping the watering on a very dried out section of my yard because "the yard is still drying out." Well yea. It's drying out. So dry it's dead in spots. (This morning, I turned off the "adjust for climate" feature.)
Looking at the forum, I see there are many many things that could affect when and why the Rachio will water the lawn. Unfortunately, the interface makes it very hard to figure these things out or to figure out when the darned thing will water again. I hope the app improves in this matter in future years.