It was particularly bad news for young American Scott Speed, who will now have to wait until Friday's sunshine to discover if he's quick enough to drive the 'third' Red Bull car in North America.
BAR (who switched to Monza and went quickest), Renault and Toyota also canned their days.
"Depending on the weather, (we) will decide if we test at Monza or Silverstone tomorrow," said a BAR spokeswoman.
McLaren braved the sodden track, though, with Pedro de la Rosa leading runners for Williams, Red Bull, Ferrari and Jordan.
Over at Monza (Italy), Marc Gene - spearheading the second venue of Ferrari's pre-America test programme - trailed Anthony Davidson, while Toyota and Sauber racer Jacques Villeneuve, slowest, also ran.