Hi John. I can see how this would be very useful for a garden water sequence. Currently SEQUEmatic uses the free Open Weather API to source weather data, and this only provides rainfall in the past 1 hour and 3 hours.
I see they have another API available which may be able to support this requirement, but I will need to look more closely to see what usage limits might need to apply in order to keep the service available for free. I'll post back here once I've had time to investigate further.