This is a pre-release. HACS only offers it if you have enabled beta versions. Everything from beta 1 is in it, plus the changes below.
New, off by default: evapotranspiration hour by hour (#818)
Settings > General > Automatic duration calculation has a new switch, Calculate evapotranspiration hour by hour (beta). With it off, which is the default, nothing changes.
With it on, PyETO sums the FAO-56 hourly equation (Eq. 53) over each hour since the zone's last calculation, instead of running the daily equation on the averages of that window. An average day hides whether the sun and the heat came together, so the daily form is biased by cloudiness. Measured against a reference implementation over a year of hourly data, the daily form read 1.14x on overcast days and 0.93x on clear ones, while the hourly sum stayed within 1.02 to 1.04 in every sky.
It needs temperature, humidity, wind speed and solar radiation in the sensor group, from a sensor or a weather service, and the site's coordinates. With forecast days set on PyETO, without a solar radiation source, or with another module, the daily equation keeps running, so switching it on never leaves a zone without a calculation. The calculation explanation says which form was used.
The hourly equation, the way a sensor group's readings are reduced to hourly rows, and most of the tests come from JustChr's fork, Irrigation Plus, MIT licensed like this integration. It is validated against FAO-56 Example 19.
If you try it, a comment on #818 comparing a few days with and without it would help decide when it becomes the default.
Drainage follows the law it claims (#783)
Above field capacity, drainage slows as the surplus drains, and it was computed as one 24-hour step at the starting rate. With the defaults an 8 mm surplus was emptied completely, where the law itself drains 3.7 mm and leaves 4.3. It now uses the exact solution, the same correction Irrigation Plus had already made. Reported with the arithmetic by @Megalos. The documentation of the drainage rate and maximum bucket now derives both from soil properties, and no longer recommends a drainage rate of 0.