The study used population weighted weather data drawn from roughly 20 million daily WeatherBug users across the United States. When the company compared all days of the year, April 25 ranked only 80th, averaging about 60F and roughly 0.1297 inches of rain. The broader dataset also shows July dominating the hottest days of the year while January owns the coldest, with January 20 averaging just 33F nationally. While no single date guarantees perfect weather everywhere in a country as large as the U.S., the numbers suggest early October may quietly offer one of the most reliable windows for comfortable outdoor conditions.