It’s going to be an exciting Race Day during the 110th running of the Indianapolis 500! Not only because of the on-track action, but also because of the question whether the race will be able to run fully as scheduled. A weather front with rain is moving toward Indianapolis, but because it mainly consists of scattered showers, it is very difficult to predict how much impact the weather will have on the race. That is why we are taking a closer look at IndyCar’s procedures for rain during oval races.

Due to speeds exceeding 230 mph (380 km/h), IndyCar races on ovals are immediately suspended once it starts raining. The track has to be completely dry before cars are allowed back on track.

Rules for delaying the race

If the track is not completely dry by the scheduled start time of 12:45PM local time, the start of the race will be delayed until the track is fully dry. IndyCar uses specialized drying equipment to dry the track, allowing a completely wet surface to usually become race-ready again within one and a half to two hours.

Suspending or ending the race early

It is also possible for rain to begin during the race itself. In that case, the race will immediately be put under caution and eventually suspended if conditions do not improve quickly enough. If the Indy 500 is suspended after Lap 101 (halfway plus one lap), race control may decide to officially end the race and wave the checkered flag. The driver leading at that moment would then be declared the winner. In that scenario, full championship points are still awarded.

If the race or a restart is delayed, it can take a long time before cars return to the track. As we saw in 2024, racing can continue until 8:00PM local time if necessary to complete the event. In the past, the race has even been postponed until Monday or Tuesday due to severe weather conditions.

Strict lightning procedures

Another important factor to keep in mind for today’s Indy 500 is the threat of thunderstorms. In the United States, strict safety regulations are in place regarding lightning near sporting events after fans in grandstands were struck by lightning in past incidents.

If lightning is detected within an 8-mile (13 km) radius of the circuit, the event must immediately be suspended and fans are required to leave the grandstands. From that moment, no additional lightning strikes may be detected within that 8-mile radius for 30 consecutive minutes before the race can resume. Every new lightning strike resets the 30-minute countdown.

So, it is going to be fascinating to see how favorable the weather gods will be to the IndyCar drivers, teams and fans today!