anyone making a "smart" water timer using today's weather forecasting would be something that could be called "The Plant Killer". my area can say that there's 80% chance of rain, yet not one drop can fall where I am while other areas can say they received .25" of rain. sounds like watering isn't necessary. oops. dead plants. There's other times where no weather is forecast, yet I've received .25" of rain. oops. wasted water. also, your "smart" decision to not water because of rain means all of the plants on my patio didn't get watered while I was on vacation/work trip/etc, which is the primary reason I bought the timer in the first place.
Your smart is dumb. Just turn the water on at the time I said. That's plenty smart for me. If I can update the schedule from my couch, great! But...not at the expense of all of this tracking bullshit