Note, prior to the weather prepopulating, you need to ensure that you have the weather scrolling across the screen at the top of the logbook.
Click on the 'black plus button' to open the section.
Click on the 'Now' button to pre-populate the selected fields. Some fields though you may have to manually edit.
Once data is entered, you can adjust each reading to suit.
Click on the 'Save' icon to save your entry.
The first entry will be saved as the 'Weather Forecast'.
You can keep adding observations throughout a day, just by clicking on the 'black plus button'.
Repeat the above process to prepopulate, adjust if required, and save each observation.