By Don Corrigan
Record-setting summer temperatures in 2026 were a gut punch for grape growers throughout the world’s northern hemisphere. Drought and heat in Continental Europe scalded grapes with wine production predicted to be at a 30-year low.
In Missouri Wine Country, the effect of relentless summer sunshine has been less dramatic on vines and ripening fruit. However, wineries do report that uncomfortable temperatures affected crowd sizes coming to their vineyards.
“It has been a rough, extended summer,” said Chuck Gillentine of Defiance Ridge Vineyards. “We had a nice spring, but the heat and humidity have been rough on grapes and customers. The heat is behind us now, so we hope for promising, beautiful days ahead.”
Located just minutes from Chesterfield in St. Louis County on Highway 94, Defiance hosts a month-long Oktoberfest celebration. Temperatures are expected to be higher than average in October, but far lower than the sizzling siege of summer.
After a hot summer, it’s a safe bet that many of the active state wineries are embracing Octoberfest. Augusta and Hermann wineries have always been at the epicenter of Octoberfest wine celebrations in Missouri.
“The heat got pretty intense all too often this summer, and it did keep crowds down. I could see that when I played at some of the local wineries,” said musician Paul Ovaitt. He’s glad Octoberfest is here.
Ovaitt, who goes by the name of “paulO” for his music gigs, also is active as a researcher and writer for the Friends of Historic Augusta. Ovaitt has an online presence with his “Tell It Like It Was,” which covers Augusta happenings.
“I did a duo performance on an unseasonably warm morning of Augusta’s Harvest Festival, and the crowd was sparse,” said paulO. “I heard the same thing from other bands this summer. I think we‘re all glad that the heat has finally broken.”
Patty Held of Missouri Wine Trail hopes the costumed characters of Octoberfest will chase away evil spirits and memories of a devilishly hot summer. Fingers are crossed that the record heat is gone.
“October is absolutely the best time to chase away those last remnants of summer,” said Held. “And if we’re going to exorcise a few seasonal spirits, we might as well do it with Missouri’s great wine.
“Our 2026 definitely gave us a summer to remember with heat alerts that seemed to go on forever,” added Held. “The heat was challenging for the vineyards, for growers, for winemakers. They watched the vines and grapes closely and made adjustments as needed.”
Held said the big conversation now is “harvest.” After such a long, hot summer, wineries are anxious to see how the grapes finish. Every growing season tells its own story, and that’s part of what makes wine interesting.
“I was talking to Jerry Mueller at Röbller Vineyard and he said a tough growing season can create incredible outcomes for the wines produced,” noted Held. “Jerry said he expects ‘exceptional’ will describe the wines of 2026.”
Record Setting Heat
St. Louis logged a record 191 to 192 days between the first 90-degree day on March 22 and the final stretch in late September/early October, breaking the previous record set in 1950.
A heat advisory lasting through September 19 marked the latest such issuance by the National Weather Service in over 20 years.
Severe heatwaves in St. Louis and Missouri throughout June, July, August, and early September regularly pushed temperatures near or above 100°F with heat index values eclipsing 110°F during peak humidity cycles.
September also was the warmest on record at 78.4 degrees on average, beating the previous record from 2019, according to the National Weather Service in St. Louis.
The growing influence of climate change was scientifically detectable in the St. Louis area’s sizzling temperatures for 14 days in September, according to Climate Central America’s Climate Shift Index.
