The extreme weather sparked a 5 percent jump in US wheat futures on Monday but prices have since steadied as the extent of crop losses was not immediately clear.
The Chicago Board Of Trade most-active wheat contract fell 1.0 percent to $4.49-1/2 a bushel by 1149 GMT, after closing little changed on Wednesday.
CBOT corn was down 0.7 percent at $3.72-1/4 a bushel while soybeans were 0.4 percent lower at $9.71-1/4, as both gave up most of their gains from the previous session.
Yield prospects for hard red winter wheat in the west of Kansas, the largest US wheat-producing state, were uncertain after a major weekend storm buried some fields under heavy snow, scouts on an annual crop tour said.
"The wheat market was consolidating in anticipation of results of the crop tour," consultancy Agritel said. "This three-day tour will be finished tonight and the conclusions will surely guide prices during the next sessions."
Partial results from the tour also pointed to above-average yield potential in some parts of Kansas, suggesting serious weather damage may be localised.
Informa Economics, meanwhile, projected 2017 US winter wheat production would come in at 1.326 billion bushels, 41 million bushels higher than their forecast in April for 1.285 billion bushels, three trade sources said on Wednesday.
Corn and soybean markets have found some support in repeated rainfall, including in last weekend's storms, that has slowed spring planting in the US Midwest.
"US croppers had made good planting progress but there is now a big question mark over how much has been washed away by weekend storms and how quickly farmers can get back in their fields," said Madeleine Donlan, an analyst at Commonwealth Bank of Australia.
However, the delays could be localised, reducing the risk to overall planting.
Thomson Reuters analysts in a daily update said delays to corn and soybean planting appeared "confined to north of the Ohio River valley".
Grain markets were also awaiting weekly US export sales figures at 1230 GMT for a fresh indication of overseas demand.
Commodity funds were net buyers of CBOT corn, wheat and soybeans on Wednesday, traders said. They were also net buyers of soymeal and soyoil.