Mavin's worldweave

Mavin's worldweave was a powerful arcanist spell of the inventive school that permanently modified the climate in a region.

Effects
With this spell, an archwizard could alter the climate of a circular area in radius (even larger for more experienced casters). The caster could target the center of the spell at any point within their field of view. One casting of the spell modified the climate one step on the following spectrum: Arctic &hArr; Subarctic &hArr; Temperate &hArr; Subtropic &hArr; Tropic Additional steps required additional castings of the spell.

Components
Mavin's worldweave required verbal and material components, but the details have been lost to history.

History
This spell was invented by the archanist Mavin in the (Netheril year 3205). It was used extensively on the northern border of Netheril to modify the subarctic climate to something more temperate.