The game will be made up Thursday with a matinee. The Reds and Guardians were both scheduled to be off but will now play at 1:10 p.m.
The Guardians have been postponed at Progressive Field by bad weather four times already this season, forcing them to play three doubleheaders.
Cincinnati won the series opener on Tuesday night, scoring the go-ahead run on a bases-loaded walk in the 10th inning to win 5-4. At 10-26. The Reds have baseball's worst record.