In 2025, St. Louis saw a city-shuttering snowstorm, the most April showers on record, a deadly tornado and humid heat waves.
The weather was unpredictable, to put it mildly. That shows in the weather data from last year, which local scientists are now releasing. Climatologists for Missouri and Illinois found both states were warmer than average, but extreme weather was the most notable trend in 2025.
Missouri may have broken its all-time record for the most documented tornadoes in 2025, and Illinois was close to doing the same.
The deadly EF3 tornado that hit St. Louis on May 16 caused an estimated $1.6 billion in damage. It joins 22 other catastrophes nationally that will cost more than $1 billion each to recover from in 2025, making last year the third highest on record for billion-dollar disasters, according to Climate Central.
Outbreaks of tornadoes in Missouri caused significant destruction and death outside St. Louis, too.
“Preliminary data shows that we had 120 tornadoes this year, which would be the state's all-time record,” said Zack Leasor, University of Missouri state climatologist.
Most of those tornado reports were concentrated east of 1-44 and happened in the first half of the year, he said. That includes the tornado that hit Rolla in March.
The total number of tornadoes will likely come down as federal agencies verify all documented reports, Leasor said, but he expects 2025 to finish with having the most or second-most tornadoes in Missouri history.
Illinois may have nearly broken the record of 139 tornadoes set in 2024, with a preliminary count of 146 tornadoes in 2025.
“This year probably comes in at number two behind 2024,” said Trent Ford, Illinois state climatologist at the Prairie Research Institute. “But what was really interesting is the vast majority, almost all of the tornadoes that happened in 2025, happened before July 1.”
Warm but not scorching
After two years when average annual temperatures broke the top five in St. Louis, 2025 was a bit cooler in St. Louis. It was the 18th-warmest year on record in Illinois and the 16th warmest in Missouri.
“It was a warm year, although gosh, you know, it's probably more remarkable when we get a year that's colder than normal,” Ford said.
St. Louis recorded its 14th-warmest year in 2025, according to the National Weather Service, while 2024 and 2023 are the second- and third-warmest years, respectively.
“Even in a year like this where we did see a relative decline in those temperatures compared to the past two years, still we are well warmer than average,” Leasor said. “And this lines up with what we've seen really over the past 30 years in Missouri, where we have this notable upward trend in temperatures.”
Thirteen of St. Louis’ 15 warmest years have happened since 1990. The recent concentration of warmth shows how human-caused climate change is affecting the region, Ford said.
“Eighteenth warmest on record in Illinois is not headline-grabbing, but it's also nothing to downplay either because we have 131 years of records,” Ford said.
In hotter years, warm winters have pushed St. Louis into the top five, like the record-breaking February heat in 2024.
“The past couple of years, we've had some very anomalously warm winter months, which can kind of skew some of that annual average as well,” Leasor said.
That didn’t happen in 2025, when winter months were cooler on average than in recent years, including the coldest January statewide in more than a decade.
But St. Louis still recorded its warmest December day on record, reaching 78 degrees on the 28th and breaking a monthly record of 76 degrees set in 2021.
April showers
Both Missouri and Illinois swung between deluges of rain and drought in 2025, according to Ford and Leasor.
“Even in drought years … we're breaking hundreds of precipitation records because when we do get rain, it comes in giant bunches,” Ford said.
St. Louis recorded its wettest April on record, with 10.85 inches of rainfall, breaking a record set in 1893. Heavy rain on just five April days made up most of that total.
Climate change is creating heavier and more frequent rainfall events in the Midwest, according to the 2023 National Climate Assessment.
But on average, both Missouri and Illinois had drier-than-average years.
“Now we've had five consecutive drier-than-average months to end the year, and that kind of contributed to that annual average being dry as well,” Leasor said. “So still plenty of drought going into 2026 left around from this past year.”
Large swaths of Missouri and Illinois are now in moderate or severe drought, according to the U.S. Drought Monitor.
