Subtle signs of summer’s death amid late season heat wave

The final month of meteorological summer is coming to an end, bringing with it a few subtle hints of fall despite plenty of lingering heat as well.

One of the biggest changes that takes place in August is a rapid loss of daylight. Between later sunrises and earlier sunsets Northwest Missouri and Northeast Kansas lose over an hour of daylight throughout the month of August, ranging from 70 minutes along the Iowa border to 67 minutes in places like Topeka and Kansas City. Daylight dwindles at a slightly higher rate in September as Earth continues orbiting the sun on its tilted axis, leaving the northern hemisphere with less and less solar radiation.

Average high temperatures in much of the continental United States peak in July and early August, including St. Joseph where an average high of 88 degrees lasts through August 7th. By the final week of this month, that same figure has fallen to 84 degrees.

Of course, climatological norms only tell part of the story when it comes to the timing of peak warm season temperatures. While the hottest days of 2026 so far took place locally in late July when highs reached 97 degrees for two consecutive days in St. Joseph, the last triple digit temperature recorded at Rosecrans Airport was on August 25th 2023 at 101 degrees. The latest 100+ degree day on record in St. Joseph was on September 28th 1953, when the mercury reached 103 degrees. 

Heat will be in no short supply across the Mid-Missouri River Valley through the final days of August and start of September, with temperatures forecast to run 8 to 12 degrees above average for several days in a row. This unfortunately means a stretch of mid 90s likely lies ahead for much of the region, even in the shadow of shorter days and longer nights.