Phoenix: First 100º+ day of 2021


The first 100º day of the year signals the unofficial start to summer, and this year, it happened right around 2:15 pm on May 5th.

Using the new 1991-2020 thirty-year averages, the average first 100º+ day occurs on May 2nd. The earliest 100º+ day occurred on March 26th back in 1988, and the latest was in 1913 when it held off until June 18th!

And if you thought this was a little late compared to recent years, you would be right. This is the latest first 100º day since May 21, 2010.

The Valley of the Sun averages 111 days a year with a high of 100º+, so looking at the positive side, only about 110 more days to go!