Where Do Isotherms Shift the Most?

Isotherms shift most over land because of the effect of differential heating of land and water.

Why are isotherms more irregular in the northern hemisphere than in the Southern Hemisphere?

Isotherms are more irregular in the Northern Hemisphere than in the Southern Hemisphere because of the marked contrasts in the distribution pattern of land and water in two hemispheres. ... Northern Hemisphere has larger landmass than the southern one.

Where do isotherms bend?

During summer in the northern hemisphere, isotherms bend towards the equator while crossing oceans and towards the poles while crossing landmasses. Isotherms are wide spaced over oceans while they are closely spaced over landmasses.