Denver and Mexico: Both Located in the Northern Hemisphere

Yes. Both Denver, Colorado (USA) and the country of Mexico lie entirely in the Northern Hemisphere (north of the Equator).

• Denver: ~39.7° N latitude.
• Mexico: Extends from ~14.5° N (southern Chiapas) to ~32.7° N (northern Baja California). Entirely north of the Equator.

The Northern Hemisphere includes all of North America, Europe, most of Asia, and northern Africa. The Equator (0°) passes through Ecuador, Colombia, Brazil, etc. — far south of both.