The North end of Bighorn Canyon is semi-arid receiving 18 to 20 inches of rain annully. The South end is in the rain shadow of the Rocky Mountains and is a high desert with average rainfall from 6 to 10 inches annually. The average temperatures are consistant throughout the park with summer highs in the 80s (F) and 90s (F), lows in the 50s (F) and 60s (F). Summer temperatures can peak over 100 degrees. High winter temperatures range in the 20s and 30s and low temperatures average in the 10s (F) and 20s (F). Winter temperatures can drop below 0 (F) with extreme wind chill factors.