Alter Aeon Online Help

Keywords are:  'druid spells weather requirements control'

Many weather spells require specific weather conditions to be possible.
For example, it's not possible to create a blizzard when it's hot -
the air temperature must first be lowered to allow snow to form.  The
'control weather' spell is the most effective way to change the
weather if you need to do so.

Here are the requirements for the weather spells:

ice fog - no requirements

blizzard - overcast, high wind, freezing temperatures

hailstorm - overcast, high wind, cold temperatures

hailstone - overcast, high wind, cold temperatures

call lightning - overcast, moderate wind

call thunder - overcast, moderate wind