From publisher blurb:
Create Raging Storms and Flying Monster Lairs in Minutes!
Enjoy quick, easy templates to spice up encounters, travel, and especially boss fights with flying or storm-based monsters. 5th Edition (5e) Game Masters can use them to run intense, cinematic encounters using air elementals, blue or bronze dragons, cloud or storm giants, as well as campaigns featuring flying creatures or monsters that live high up in hills, mountains, or in the clouds themselves.
In this extreme template pack, you get environment rules as well as new monsters and treasure ideas for:
Cloud Castle (magical terrain)
High Elevation (nonmagical terrain)
Lightning Storm (nonmagical terrain)
Thunderstorm (nonmagical terrain)
Tornado (nonmagical terrain)
Windstorm (nonmagical terrain)