No rain fell on the 0.875-mile track on Saturday, but severe thunderstorms moved through the area on Friday.

Qualifying was delayed more than an hour to allow track officials to tend to the water issue. Three drivers - Hideki Mutoh, Scott Dixon and E.J. Viso - made a four-lap qualifying attempt before the session was scrubbed.

Castroneves was awarded the pole since entrant points determine the starting lineup. The Brazilian driver and reigning Indianapolis 500 champion did not compete at St. Petersburg due to his federal tax evasion trial earlier this year, but Will Power drove his car to a sixth-place finish in the season- opener.

"Those points definitely kept me in the front of the pits, and now gave me the pole position at Iowa," Castroneves said.

Ryan Briscoe, the current IndyCar points leader, will join his Team Penske teammate on the front row.

Target Chip Ganassi Racing teammates Scott Dixon and Dario Franchitti will share row two, while Danica Patrick and Dan Wheldon, the defending race winner, occupy the third row.

Tony Kanaan and Marco Andretti from Andretti Green Racing will start from row four. Newman/Haas/Lanigan Racing's Graham Rahal and Justin Wilson from Dale Coyne Racing will roll off from the fifth row.

Sunday's race is scheduled to start around 1:30 p.m. (et).