The scorching temperatures expected this week in Europe follow a hot, dry spell in Russia and Ukraine, and concern over crop damage countered seasonal supply pressure on prices as harvests get going across the northern hemisphere.
Chicago corn and soybean prices rose as weekend rain in the US Midwest kept the focus on waterlogged conditions that have disrupted planting and put a question mark over this year's harvest.
Grain markets are awaiting weekly US Department of Agriculture crop progress data later on Monday and revised USDA acreage estimates on Friday to gauge the impact of torrential rain in US grain belts this spring.
The Chicago Board of Trade most-active wheat contract was up 0.4pc at $5.33 a bushel, as of 1201 GMT, while front-month wheat on Paris-based Euronext was up 1.0pc at 182.50 euros a tonne.
The CBOT benchmark recovered from an earlier fall after Euronext opened higher, with the Paris contract reaching a one-week high at 183 euros.
The intense heat in western Europe, which will see temperatures approach 40 degrees Celsius (104°F) in Paris in the middle of the week, could curb a recent trend of rising cereal harvest forecasts.
"The heat will be detrimental for crops in reproductive development looking to rebound from last season's crippling drought," Refinitiv Agriculture Research analysts said, noting temperatures would be over 10 degrees above normal.
A hot, dry spell in parts of Russia and Ukraine was also being monitored by wheat traders, although temperatures were expected to moderate this week while the arrival of first harvest supplies was also capping prices.
CBOT corn added 0.7pc to $4.45-1/2 a bushel, while soybeans gained 0.8pc to $9.09-1/2 a bushel.
Corn and soybeans eased on Friday as weather forecasts pointed to warmer conditions in the week ahead.
But widespread rain over the weekend may have kept some fields waterlogged, and some light showers are forecast this week.
"The US Midwest is mostly wet to very wet," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.
"The wet conditions now have less impact on planting because that window has closed for most growers.
From here the impact is on crop development and yield."