Do you mean you want to rotate the axis labels so that the temperature labels are vertical?. If so you can double click on the labels and in Plot Details you can change the rotation to 90 degrees
I just want to change e.g. the alignment of temperature. But if I am doing it the way you proposed both axis descriptions (temperature and daytime) are vertically aligned. But how can I just align e.g. the temperature vertically?
When you use two groups for raw boxed data, clicking on one of the two axis labels will open Axis dialog and you will see you have Bottom 1 and Bottom 2 on the left panel. Select Bottom 1 and expand the Table section. Then check the Independent Format check box and this will let you customize your two axis labels separately.
Once you have check this box it will tell you that : Format branch is turned on for new table rows. and the Bottom2 branch which was greyed out before will now be un-greyed and you will be able to customize it.