Arizona Fall League – Playing Games in Summer Yet Escaping the Desert Heat
A scheduling shift for Arizona Fall League (AFL) baseball has its teams playing games in summer yet creatively escaping the heat. Cancelled for 2020, this league should return in 2021 with the second rendition of an earlier opening day originally introduced in 2019. This change moved the season three weeks earlier, to start in mid-September and end with the championship game on the last Saturday of October. The chart below depicts the temperature effect of trading mid-autumn days for three weeks near the fall equinox.
Having seen the extreme heat across the Desert Southwest at the start of September 2020, one might well be concerned about the potential weather impacts of an earlier AFL season. What are dedicated fans getting themselves into? Will I still want to travel to these games in 2021? Though baseball is a sport not necessarily halted by the desert heat (note that a rookie-level Arizona Summer League has been playing in outdoor venues through the hottest part of the year since 1988) the AFL is kind to those of us from cooler climates, with the September portion of the schedule containing only night games. In 2019, the early season September nights cooled to the upper 60s and lower 70s. During October, some of the games start over the noon hour and others in the early evening, For those who don’t like the mid-day warmth, it can be as much as 15 degrees cooler by the middle innings of an evening game!
Average temperatures are dropping very quickly during the season, cooling by about ten degrees every four weeks! The average high in Phoenix drops below 100 during the third week of September, and crosses the 90 degree mark around October 12th, which was very close to the former starting date of the AFL. By mid-November, average highs are in the mid to upper 70s.
Monsoon season, featuring not only increased chances for afternoon thunderstorms, but also higher humidity, peaks during August, and retreats during September. These fall months each average a half to two-thirds of an inch of rain, with measurable amounts falling on about four days in each month. So, the area has dry weather most of the time. Hurricanes from the Pacific Ocean occasionally move into the southwest US in much weakened but still moisture-laden form. Several of Arizona’s most prolific rainmakers have occurred with former Pacific hurricanes, and the historical peak of these occurrences seems to have centered on the last week of September and first week of October. There have been sixteen tropical systems to impact Arizona since 2000 (see the list here) but none have occurred later than the most recent system of this type on October 15, 2018 when the remnants of Hurricane Sergio passed through as a tropical depression.