Phoenix Sky Harbor has recorded 29 days so far this year with a high of 110º or higher; this is now the 4th most Phoenix has recorded since records began in 1896.

So how has the number of 110º or higher days changed throughout this period of record?

For starters, in 1911 there were no 110º+ days, and in 2011 there were 33 days, which currently stands as the record. The current climatological 30-year average (1981-2010) is 18 days per year, but let's take a closer look at the average over time.

Examining the rolling 30-year average from 1896 to 2018, it's easy to see that it is going up. In 1925, the average was just five days per year, and now including this year, the average is 20 days. Even though we see an increasing number of 110º days, there is a piece of good news, and that is that the rate of increase has slowed (more text below graph).