Sorry if this has been covered elsewhere on the forum already...
I am using basic watering - not flex schedules. I had trouble setting up flex schedules because I can't give it a recommendation on how long to water - had to instead give correct parameters to have it conclude the right watering schedule, instead of being able to give it a starting point which I think would be more intuitive. Anyhow...
I don't feel the current weather delay feature is very effective and has some easy algorithmic improvements that could be done.
Watering is skipped based on the forecast - but this is fairly imperfect, and opens up several contingencies that are bad:
1) If the forecast anticipated X inches of rain, but the actual rain was say 1/2 or 1/3 that amount, it may warrant additional watering the next day. I had a situation yesterday where the forecast was .34 inches, but we got .03. So, I ran manually. I think this is an easy thing to check though and correctly fix with a light watering the following day.
2) Also, some watering strategies involve very deep infrequent watering, and expose a need for 'ratcheting' down of your watering based upon observed precipitation. Perhaps flex schedule has this feature, but I wish basic rain delay would sometimes as well. I run my established fruit trees on 1 hour drip 'drench' every 10 days in the summer (14 days for spring/fall and 21 days for winter)). Ideally, rain would be reducing this gradually down to zero. I don't know the user friendly way to do this, but I feel like the Iro should know if there was significant rain in between the waterings and have a way to fractionally reduce somewhat based on a 'reasonable' guess of how many inches of rain the zone's vegetation type is probably consuming. With current functionality, rain delay is basically useless for this zone because a skip is almost certainly incorrect unless it's a big thunderstorm, AND it should basically be on perpetual rain delay in the winter, but probably will never get triggered then because of a lack of rain day-of.
I understand that Flex is supposed to solve some of this, but getting Flex to understand how much it should water your yard is a bit challenging in the first place, so I'm trying to use weather delay on basic watering to help me.