With the 100th running of the Indianapolis 500 coming up this Memorial Day weekend; we looked at the weather from the first 99 races. Between a National Weather Service Cooperative station in nearby Whitestown, and the Indianapolis International Airport, we have temperature and precipitation data going all the way back to the first Indy 500 in 1911. That first race was a grind, taking over 6.5 hours to complete, however, it was dry with high temperatures in the low 80s. Over the years this would prove to be nearly ideal conditions for the last week of May.
Though races can run in any temperature, precipitation is the limiting factor in nearly all forms of automobile racing. IndyCars do have rain tires and will race in wet conditions, however, with speeds in excess of 220mph at the Indianapolis Motor Speedway, it has been deemed “unsafe” to run in anything other than dry conditions. Good luck has prevailed for the most part in that category as rain has delayed just 10 races, 7 of which were rain shortened, and only 3 had to be run over multiple days. A notoriously bad stretch occurred between 1973 and 1976 which had 3 rain shortened races, 2 of which took three days to finish.
Severe weather is not uncommon for the end of May; fortunately it has occurred only one time on the day of the race. May 30th, 2004 proved to be the wettest Indy 500 in the race’s history with 3.80” of rain falling during that calendar day. In fact, the race was delayed by rain and thunderstorms at the beginning, with two more delays occurring during the race. The line of severe storms that ended the race after 180/200 laps eventually spawned an EF2 tornado and led to widespread damage to the southern metro area but luckily missed the Speedway (and the nearly 250,000 people still there) by only 6 miles.
Hopefully we don’t see anything like that for this year’s Indy 500. As mentioned before, only 10 races have been affected by rain, but a trace or more has been reported on race day nearly half of the time (49/99). The temperatures are a better story with an average high temperature of 78.1 degrees (F) and nearly 45% (44/99) of the races reaching the upper 70s/lower 80s.
As we look ahead to the "Big Race" this weekend, the big question is, will Mother Nature cooperate? As of right now, it doesn't look like anything significant is forecast to impact the Indy 500 on Sunday. However, it does look like a more summer-like pattern will be in place. This means there will be sunshine, along with fair weather clouds, some increased humidity, and temperatures 80 - 85. Although we can't rule out a late day spotty thunderstorm on race day, the activity will most likely be west of the speedway. Drivers, start your engines!!
**Lead image from Wikipedia, title: "The starting field of the 2007 Indianapolis 500 in formation before the start" From user: The359 under CC BY-SA 3.0 license
