This week's respite in the weather has proved an illusion. After first cresting in St Louis at 46.9ft, the Mississippi delivered a fresh record of 47ft on Tuesday, and is expected to top that when a third crest, fuelled by a new surge of the Missouri, arrives in the middle of next week.
The city itself should be safe, protected by its 11-mile flood wall, 52ft high, although at least one leak was reported yesterday. But the suburbs of South St Louis will once more be at the mercy of the bloated Des Peres river which has already smashed through levees along its banks, turning entire neighbourhoods into fetid, brown lakes.
Across the region, the disaster's toll mounts remorselessly. According to the Red Cross, 33 people have died and almost 33,000 have lost their homes. Damage estimates range anywhere up to dollars 10bn, while 16,000 square miles of some of the world's richest farmland - an area one-third the size of England - are under water.
Computer-enhanced maps show a flooded area as large as one of the Great Lakes straddling the borders of Iowa, Nebraska and Minnesota. Some areas received a further 6in or 7in of rain over Thursday night. President Clinton has now declared parts of Kansas a disaster area, making it the eighth state eligible for emergency aid from Washington.
When that relief comes is uncertain. Congress was supposed to approve the dollars 3bn package on Thursday, but squabbling over whether additional spending cuts were needed to find the money delayed a House of Representatives vote until Tuesday at the earliest.
On the ground, it was a mixed story of triumph and failure. Drinking water has returned for the 250,000 residents of Des Moines, Iowa. But the Mississippi broke through levees to flood a 15,000-acre island downstream of St Louis.
While the heartlands are submerged, south-eastern states have been sizzling in 100F heat for weeks now. South Carolina yesterday reported dollars 200m of drought damage. The culprit is the same: a high pressure zone in the east which has trapped the storm system over the Midwest. Forecasters predict no change for at least 10 days.