5 Watts, Nearly 100 Miles

Today, I logged a Summits-on-the-Air contact with Philip, KK6YYD (my role was that of "chaser"). He was activating Mt. Price (W6/NS-377), near South Lake Tahoe, California. We were on 2 meters (146.520 MHz) FM. I find this contact to be especially noteworthy because we were both operating at 5 watts (indoors on a handheld, in my case) and were approximately 98 miles (158 km) away from each other. It was a clear, hot, sunny day of over 100 degrees Fahrenheit (37+ degrees Celsius); could that have been a factor in helping the propagation?