No play was possible due to rain in Group C leaders Sussex's scheduled Clydesdale Bank 40 away game against the Unicorns at Southend-on-Sea.
After a series of pitch inspections, the last at 5.15pm, the umpires ruled out the prospect of a result and called the game off.
Both teams pick up one point for a 'no result', ending Sussex's 100% start from their first three matches but leaving them a point ahead of Warwickshire at the summit.
The Unicorns have four points from six games and are one behind Yorkshire, whose clash with bottom side Northamptonshire was also washed out.
