When the weather is 70°F I am content, not too hot, not too cold, just right. Brian Brettschneider is a Climatologist with a PhD and a sense of humor, or adventure. He sorted through 8,000 weather stations across the US, looking for the 30 year average high temperature each day of the year and devised a 9,125 mile cross-country trip following optimal temperature. Then he added Canada to his calculation. He came up with this 13,325 mile road trip through North America to follow 70°F normal high temperature.