Friday brought traders a number of conundrums, the weather being only one, and whether indeed the US will see lower temperatures ahead, and maybe a little rain.
That's the forecast, with cooler air set to swing in this weekend, bringing some, but not widespread, rains with it.
"The eastern upper Plains will see light rains with the front passage, under 0.25 inches and 40% coverage, the western Corn Belt 50% coverage of 0.25-0.75 inches and the eastern Corn Belt about the same," WxRisk.com said.
"However, southeast Indiana, southern Ohio and much of Kentucky could see up to 2 inches of rain Sunday and Monday."
A US broker said: "Cooler temperatures and some rain will help tame things down this weekend but we aren't seeing any meaningful amounts expected."
The next challenge is the date.
Not only is it the end of the month, a day when by reputation funds close positions and withdraw money to pay off customers, but the weekend is a long one in the US too, with the Labor Day holiday on Monday.
This too should encourage position closing, given an extra day without being able to trade, and in a weather market.
(After all, even if the Midwest does cool off, there is the threat of an early frost to think of as well.)
'Trying to fill its gap'
As for technical guidance this has puzzled many too, in that the December corn contract, having "gapped" higher on Monday (the bottom of its trading range being well clear of the top of the previous session's) failing, as many investors had expected, to weaken and fill in that chart void.
"December corn has been trying to fill its gap from Sunday night but has still been unable," the US broker said.
On a negative note, the contract did on Friday surrender its 10-day moving average, at $4.80 ½ a bushel.
For soybeans, the November contract in early deals dipped its toe into its own chart gap, from Monday, before recovering.
Still, the contract "has had a few days of making lower highs which haven't held. This is not a great technical sign for soybean strength".
'Turned from decently favourable to questionable'
"Still the market may hold premium just for the fact that it is extremely difficult to predict final bean yield at this stage," the broker added.
"Conditions have turned from decently favourable to questionable in a matter of a few weeks."
And as an extra reason for investors not to turn tail yet, US weekly export sales on Thursday proved firm, 674,000 tonnes for soybeans (at the top end of expectations), while proving comfortably within forecasts for soybeans at 869,000 tonnes.
There is "thus no sign as yet that the recent price surge is dampening demand", Richard Feltes at broker RJ O'Brien said.
Prices were lower, but with declines not extreme as of 09:35 UK time (03:35 Chicago time), with November soybeans down 1.`% at 13.54 ¾ a bushel in Chicago, feeling some extra pressure from the sale by China of 393,000 tonnes of the oilseed from state reserves, 79% of crop on offer.
December corn was 0.8% down at $4.77 ¾ a bushel.
Wheat holds on
Wheat, which has been a follower of late, actually outperformed, easing a more modest 0.25 cents to $6.54 a bushel in Chicago for December delivery.
In part, this represents a key technical point, in standing just above 10- and 20-day moving averages, (the only ones the contract stands above).
Furthermore, wheat may find some support from lower row crop prices in that many investors have hedged long corn or soybean positions against wheat shorts.
And there are some fundamental reasons for support too, with US weekly export sales decent at 551,000 tonnes for wheat, at the top end of market forecasts.
Australia, Canada thoughts
Furthermore, in spring wheat, ideas of lower protein are offsetting pressure from harvest, as combines start rolling in Canada in earnest too.
"There is talk that Canadian producers are finding some pockets of better protein as the harvest expands, but it's likely too early to tell," Brian Henry at Benson Quinn Commodities said.
"Given generally favourable growing conditions for the North American spring wheat crop, the general feeling is protein levels will stay below average for most areas."
And in Australia, Cargill's AWB grain trader issued a reminder of less-than-ideal conditions in parts, by naming "isolated dry conditions in parts of New South Wales and Western Australia", as well as a weak Australian dollar and higher Chicago futures, as cause to lift its pool price forecasts.
Still, at Luke Mathews at Commonwealth Bank of Australia noted: "A possible headwind for international wheat values is the likely resumption of Indian wheat exports following the recent free fall in the Indian rupee."
Soft commodities opened generally with small losses, although cotton managed a gain of 0.3% to 83.47 cents a pound in New York for December delivery, bouncing from its lowest close in two months.
There are reasons to sell, with US export sales, at 68,800 running bales in the latest week, meaning that 2013-14 (which started at the beginning of August) has got off to a poor start, with trade down 25% year on year.
Furthermore, "drier weather in the southeast US cotton belt is seen benefiting cotton crops", Mr Mathews noted.
However, stocks for delivery against New York futures continue to fall, reaching 23,471 bales as of Thursday, a nine-month low, and well below levels above 600,000 bales hit last month.