Northern Route (via I-70 through Utah and Colorado Rockies)
Pros:
Scenic drive through dramatic desert and mountain landscapes.
Fewer weather-related issues typically occur in early October. TripAdvisor users note that I-70 “is unlikely that weather will play a factor for your drive in October.”
Tripadvisor
Tripadvisor
Cons:
Denver’s autumn weather can be unpredictable — frequent temperature swings (“Hoodie City”) and occasional early snow aren’t unheard of.
Reddit
High mountain passes like Monarch Pass or Wolf Creek Pass (if included) may be at risk of early storms.
Wikipedia
+1
Southern Route (through Arizona / New Mexico)
Pros:
Generally lower elevation routes, which often means more stable, warmer weather.
Still offers gorgeous scenery — especially through areas like Monument Valley or the Grand Canyon.
Lazytrips
Cons:
Weather is still variable. As shared by road-trip enthusiasts:
“You can get just as snowed in in New Mexico, Flagstaff, and crossing the Sierra Nevada south of Vegas…”
Reddit
Early October snow in higher-altitude sections (e.g. Flagstaff/Arizona) can surprise drivers.