COLUMBIA, Mo. – Missourians experienced a wide variety of weather in 2021, from extreme cold in February and record December warmth to summer floods, fall drought and winter tornadoes, says University of Missouri Extension state climatologist Pat Guinan.
Despite these extremes, the Show-Me State overall had a favorable growing season in 2021.
January: Overcast and mild
The year started off with alternating periods of seasonably mild weather followed by slightly cooler-than-average conditions. More than half the days in January were overcast, keeping most overnight minimum temperatures above normal throughout the month.
Based on official climate data, the average statewide temperature for January was 33.6 F, or 4.2 degrees above the long-term average (1901-2000). This follows the general trend of mild January temperatures over the past couple decades, says Guinan.
The coldest weather was toward the end of the month, when the northern half of the state dropped to single digits and lower.
“An unsettled January weather pattern impacted Missouri with significant precipitation events bookending the month,” says Guinan. Precipitation statewide averaged 3.33 inches, or 1.24 inches above the long-term average.
Some snow and ice events occurred, with heaviest monthly snow totals affecting portions of far northern Missouri, where 7.5 to 12 inches were common. The heaviest monthly snowfall was in the northwestern tip of Missouri, where an observer from Nodaway County reported 13.5 inches.
February: Ninth-coldest on record
It was looking to be another mild winter in Missouri, but Mother Nature had a different plan for February. The polar vortex migrated from near the north pole to southern Canada and the north-central U.S., bringing exceptionally cold weather to the central U.S. from North Dakota to Texas. On Feb. 16, two locations in northwestern Missouri – Corning in Atchison County and Smithville Lake in Clay County – reported morning low temperatures of minus 26 F.
Temperature departures in Missouri for Feb. 6-19, 2021, averaged more than 20 degrees below normal, with a statewide average temperature of 10.2 F. The last time Missouri saw a colder two-week period was more than 30 years ago, Dec. 11-24, 1989. Statewide, temperatures for February averaged 24.4 F, or 9.4 degrees below the long-term average. It was the coldest February since 1979 and the ninth-coldest February on record, says Guinan.
Total February precipitation statewide averaged 1.15 inches, or 0.87 inches below the long-term average. Lightest monthly totals were generally between 0.5 and 1 inch and fell over the western half of the state. Heaviest totals were in the Bootheel, from 3 to 4 inches.
Because of the cold weather, most precipitation fell in the form of snow, with above-normal snowfall reported statewide, ranging 6-14 inches for the month. An observer just south of Kirksville reported 15.9 inches.
The anomalously cold weather was reflected in unusually high heating bills. With wind chills dropping to minus 30 F, cold stress on outdoor workers, exposed livestock and pets was unrelenting. Conditions challenged ranchers with keeping newborn calves warm, feeding hay and routinely chopping ice-covered ponds for water. Freezing and thawing of lake ice damaged docks, and the extended period of cold weather contributed to a deeper than usual frost line in the soil, with numerous reported instances of frozen and broken pipes.
March: Wet and warm
Mild weather dominated the Show-Me State in March, especially during the first and last 10 days of the month, which were separated by cool, cloudy and wet conditions in the middle of March. The statewide average temperature for the month was 49.9 F, or 6.3 degrees above the long-term average.
March precipitation was above normal statewide, with only a handful of counties in north-central and northeastern Missouri reporting near-normal precipitation. The average statewide total for March was 5.26 inches, or 2.05 inches above the long-term average. Wet conditions limited spring fieldwork across the state.
April: A roller coaster
April was a roller coaster, with above-average temperatures at the beginning and end of the month and cooler conditions in between. The temperature statewide averaged 54.2 F, or 0.3 degrees below the baseline period mean (1901-2000). Three out of the past four Aprils have been cooler than average, says Guinan.
April 21-22 brought record low temperatures to the state. Farmers reported freeze damage to crops in vulnerable growth stages, including some early planted corn in southeastern Missouri, as well as some fruit crops, ornamentals and annuals. Producers also reported lodging of forage crops.
Average April precipitation statewide was higher than normal, totaling 4.36 inches, or 0.39 inches above the baseline period mean. An unusual late spring snow affected Missouri April 20-21. Accumulations were generally 1-5 inches statewide, mostly on elevated and grassy surfaces.
According to the Missouri Agricultural Statistics Service, for the week ending April 25, corn planting was 23% complete, 21 percentage points behind the five-year average. Stock water supplies were reported mostly adequate at 94%, with 81% of the hay supplies and other roughages adequate and 6% surplus. The majority of pastures, 67%, were in good condition and 27% in fair condition. Topsoil moisture supplies were mostly adequate (82%) to surplus (17%) statewide. Subsoil moisture supplies were mostly adequate (87%) to surplus (12%).
May: Cool was the rule
Cool was the rule in Missouri during May, with maximum daily temperatures below average. The statewide average temperature was 62.3 F, or 1.9 degrees below the long-term average.
May precipitation varied across Missouri, ranging from 2-3 inches in some east-central counties to more than 10 inches in parts of west-central and southwestern Missouri. The statewide average total of 4.99 inches was 0.33 inches above the long-term average. The wet conditions followed the trend of the past few decades: May has been wetter than average in 22 of the last 32 years, or 69% of the time.
According to the Missouri Agricultural Statistics Service, 92% of the corn and 49% of the soybean crop had been planted as of May 30, 2021; the five-year average is 91% and 53%, respectively. The cool, cloudy weather generally benefited pastures, with 71% of them reported in good condition and 6% excellent. Hay supplies and other roughages were listed at 85% adequate and 4% surplus. Stock water supplies were reported mostly adequate at 87% and 13% surplus. Topsoil moisture supplies were mostly adequate (57%) to surplus (42%) statewide. Subsoil moisture supplies were mostly adequate (74%) to surplus (25%).
June: Impending drought to flooding
The statewide average monthly temperature for June was 74.8 F, or 1.8 degrees above the baseline average. The warmer-than-average temperatures followed the trend over the past several years, where only one June since 2005 has been below average, says Guinan.
Dry and hot conditions emerged during the first couple weeks of June, and producers were concerned as critical corn growth stages neared. During the third week, however, concerns shifted from impending drought to flooding. Most of the rainfall in June came during the last 12 days of the month, and a few locations reported their wettest June in decades. Columbia Regional Airport reported 0.1 inch June 1-19 but received 10.85 inches for the month, making it the second-wettest June since 1890 and the wettest June since 1928, when 14.86 inches was reported.
June rainfall was above average statewide but variable across Missouri, ranging from 10-15 inches or more in parts of northwestern and central Missouri to less than 2 inches over portions of southern Missouri, according to radar estimates. The statewide average rainfall total was 5.98 inches, 0.96 inches above the baseline average.
The extraordinary amount of rainfall that fell over parts of the state during the last 12 days of June flooded thousands of acres of low-lying fields and bottomlands. This resulted in nitrogen deficiencies in corn. On the other hand, pastures greened up nicely with the milder temperatures and abundant rainfall.
Wetter conditions near the end of June meant no drought for the Show-Me State, according to the U.S. Drought Monitor. A couple areas showed abnormally dry conditions, including a few northwestern counties bordering Iowa and a thin corridor in southeastern Missouri extending from Ste. Genevieve and Perry counties southwest to parts of Carter and Shannon counties.
According to the Missouri Agricultural Statistics Service, 2% of the corn was silking for the week ending June 27, compared to a five-year average of 15%. Soybean was 96% planted, compared to a five-year average of 91%. Topsoil moisture supplies were rated 86% adequate to surplus, and subsoil moisture was rated at 91% adequate to surplus. Corn was rated mostly good to excellent at 58%, and soybean was reported at 57% good to excellent. Pasture conditions were mostly good to excellent at 72%. The majority of hay supplies and roughages were adequate at 81%. Stock water supplies were reported to be in adequate (85%) or surplus (12%) condition.
July: Wetter than average
July in Missouri saw seasonably cool conditions, with data indicating a statewide average temperature of 76.6 F, or 1.1 degree below the long-term average. Daily maximum temperatures for July were mostly below average, generally climbing into the 80s. There was a period of hotter weather during the last week of the month when temperatures reached into the 90s. With one exception, there were no triple-digit temperatures reported in the state during the entire month. An observer 2 miles west of Cosby, Missouri, in Andrew County, reported a high temperature of 100 F on July 30.
Minimum July temperatures were mostly in the 60s, with some minimums in the 70s toward the end of the month. There were more above-average minimum temperature days than maximum temperature days, due in part to above-average dew point temperature. High dew points elevate minimum air temperatures while suppressing maximum temperatures. The high July dew points in 2021 followed the trend Missouri has experienced over the past few decades, says Guinan.
The statewide average July rainfall total was 4.86 inches, or 1.15 inches above the long-term average. It was the fifth consecutive month with above-average precipitation.
According to radar estimates, heaviest July rainfall fell over parts of northeastern and southeastern Missouri, where 5-8 inches were common. A few areas reported more than 10 inches for the month. Driest conditions were across parts of northwestern and west-central Missouri and a few isolated pockets in southern sections.
According to the Missouri Agricultural Statistics Service report for the week ending July 25, 2021, 10% of the state reported topsoil moisture supplies in short to very short condition, with 84% of the state reporting topsoil moisture in adequate condition. Statewide, subsoil condition was reported 5% short to very short and 89% adequate. Corn, soybean and pasture conditions were reported at 8%, 9% and 3% in poor to very poor condition, respectively. Most of the corn and soybean were reported in good to excellent condition at 66% and 61%, respectively. Most of the pasture was in good to excellent condition at 75%. Most of the hay and other roughages were adequate to surplus (93%), as were stock water supplies (97%).
All of Missouri was “drought free,” according to the U.S. Drought Monitor for July 29, 2021. A small area of abnormally dry conditions was reported in southeastern Missouri, affecting some southeastern Ozarks counties.
August: Hottest in a decade
Missouri saw its hottest August in a decade in 2021. Statewide, temperatures averaged 77.4 F, or 1.4 degrees above the long-term average. There were below-average temperatures during the first week of August, followed by warmer-than-average conditions for much of the rest of the month, including several days with high temperatures in the 90s and lows in the upper 60s and lower 70s. Most locations, again, reported no triple-digit heat for the month.
Daily summer temperatures in 2021 reflected the overall trend of the past few decades, with no prolonged periods of extreme high temperatures. Mean summer temperature data (June-August) indicates slightly above-normal conditions in 2021. The statewide average summer temperature was 76.3 F, 0.8 degrees above the long-term average. Summer weather patterns over the past several decades indicate little change in maximum temperature trends. However, minimum summer temperatures have been warming, primarily due to above-average summer dew point temperatures in Missouri.
August was drier than normal in Missouri, with a statewide average precipitation of 2.99 inches, 0.72 inches below the long-term average. Typical of the summer season, August rainfall was highly variable, ranging from less than 1 inch to more than 11 inches, according to rain gauge observations. Most areas received below-average rainfall. Radar estimates indicated pockets of more than 5 inches in parts of the state, but most locations got less than 3 inches.
The U.S. Drought Monitor map for the week of Aug. 31, 2021, showed small areas of abnormally dry conditions affecting parts of central, southwestern and southeastern Missouri.
According to the Missouri Agricultural Statistics Service report for the week ending Aug. 29, 2021, 67% of the state reported topsoil moisture supplies in adequate condition with 2% surplus, whereas 27% of Missouri reported short topsoil moisture supply and 4% very short. Subsoil moisture supplies were reported 74% adequate and 2% in surplus condition, compared to 21% of the state reporting subsoil moisture supplies short and 3% very short. Corn was reported 63% in good to excellent condition, compared to 77% last year, and soybean was reported 59% in good to excellent condition, compared to 75% in 2020. Pastures were rated at 60% in good to excellent condition, compared to 55% in 2020. Hay and other roughages were 91% adequate to surplus, compared to 87% in 2020. Stock water supplies were 89% adequate and 11% short to very short.
September: Mild and very dry
Summerlike weather continued into September, with above-average daily temperatures for most of the month. The statewide average September temperature of 71.6 F was 3.4 degrees above the long-term average. The mild month followed the trend over the past decade, with only three out of the past 10 Septembers being cooler than average
Precipitation in September averaged 2.35 inches statewide, 1.75 inches below the long-term average. It was the second consecutive dry month, with an August-September statewide average rainfall total of 5.34 inches, 2.47 inches below average, and the driest August-September period since 1999, says Guinan.
September rainfall totals varied across Missouri, with radar estimates showing highest amounts in parts of west-central and southeastern Missouri and the driest conditions across portions of northern Missouri.
The U.S. Drought Monitor map for Sept. 28, 2021, showed more than half of Missouri had abnormally dry conditions to moderate drought. Driest conditions were localized and affecting portions of southern Missouri.
According to the Missouri Agricultural Statistics Service, as of Sept. 26, 2021, most of the corn crop was in good (54%) to excellent (13%) condition. Remaining corn conditions for the year were 24% fair, 7% poor and 2% very poor. Corn harvest was on pace with the five-year average at 34%. Much of the soybean crop in 2021 was also in good (56%) to excellent (8%) condition, compared to 61% good and 20% excellent at the same in the previous year.
Most of the hay and roughages were adequate (85%) to surplus (5%) in 2021, with 8% short and 2% very short. Stock water supplies were mostly adequate at 82%, with 15% short and 3% very short. Most pastures were reported in fair (41%) to good (40%) condition, with 3% in excellent condition and 16% in poor or very poor condition.
The majority of topsoil moisture conditions were adequate (52%) while 40% were reported short and 8% very short. The majority of subsoil moisture conditions were also reported to be adequate (64%), with 31% short and 5% very short.
October: Warm and wet
The statewide average October temperature was 60.5 F, or 3.5 degrees above the long-term average, making it the warmest October since 2016.
Warm conditions dominated the first three weeks of October, with high temperatures on many days reaching the 70s. Most of Missouri sees its first fall freeze in October, but in 2021 only a handful of locations in northwestern Missouri and the eastern Ozarks reported temperatures at or below 32 F. Later than usual fall freezes have been the trend over the past couple decades, says Guinan.
A wetter pattern returned in October, with statewide average precipitation totaling 5.86 inches, or 2.67 inches above the long-term average. It was the wettest October since 2014 and the ninth-wettest October on record.
According to radar estimates, most locations saw more than 5 inches of rain for October, with scattered pockets of 3-5 inches elsewhere. Lightest totals were in east-central Missouri around the St. Louis metropolitan area. The highest mean county rainfall estimate for the state was in Mercer County with 9.87 inches. St. Louis County and St. Charles County both reported the lowest total of 3.33 inches.
Occasional wet periods in October limited opportunities for crop dry-down and fieldwork, but good September weather gave producers a head start on harvest. According to the Missouri Agricultural Statistics Service, for the week ending Oct. 31, corn and soybean harvest was 86% and 59% complete, respectively, 4 percentage points ahead of the five-year average for corn and 2 points behind the five-year average for soybean. The majority of topsoil and subsoil moisture conditions were reported adequate at 80% and 83%, respectively. Hay supplies were mostly adequate (87%) to surplus (4%), with only 8% reported short and 1% very short. Stock water supplies were mostly adequate (92%).
Wet and warm October conditions and no hard freezes eased livestock winter feed supply concerns with robust cool-season grass growth. The U.S. Drought Monitor also reported improving conditions by the end of the month, with only small residual pockets of dryness affecting the Show-Me State.
November: Autumn ends warm and dry
Missouri saw seasonably mild weather in November, with data indicating a statewide average temperature of 45.5 F, 1.9 degrees above the long-term average. Typical daytime highs for the month were in the 50s and 60s, with lows in the 30s and 40s. It was the warmest autumn (September-November) since 2016 and the seventh-warmest autumn on record for Missouri.
Statewide average precipitation totaled 1.05 inches, or 1.86 inches below the monthly long-term average of 2.91 inches. It was the third month since August with below-average precipitation and the driest autumn since 2017.
Heaviest monthly precipitation was over parts of northwestern, west-central and southern Missouri, where 1-2.5 inches were common. Lighter amounts, generally less than 1 inch, fell across the rest of the state. Apart from a thin corridor in northwestern Missouri, rainfall was below normal statewide. Severe storms were nonexistent in November, but there were vibrant fall colors and beautiful sunsets during the month.
By the end of November, the U.S. Drought Monitor showed abnormally dry conditions in more than one-third of Missouri, especially across the eastern half of the state. A small area of moderate drought was noted over southeastern sections. The drier conditions provided numerous opportunities for fieldwork and outdoor construction projects.
As of Nov. 28, 2021, the Missouri Agricultural Statistics Service reported 88% of the topsoil moisture supplies in adequate condition and 85% of the subsoil moisture supply as adequate. Soybean harvest was 95% complete, compared to the five-year average of 95%. Winter wheat progressed to 94% planted, compared to the five-year average of 94%. Winter wheat was reported to be 86% emerged, 5 percentage points higher than the five-year average, and 62% in good to excellent condition. The state reported 87% of its hay supplies and other roughages as adequate and 95% of the stock water supplies adequate.
December: Warmest in 127 years, first December derecho
Unusually mild conditions dominated Missouri during the final month of the year. Preliminary data indicated an average statewide December temperature of 44.3 F, or 11.3 degree above the long-term average. It was Missouri’s warmest December in the past 127 years (1895-2021), surpassing the previous December record set in 2015.
Preliminary precipitation data indicated a statewide monthly average of 2.17 inches, or 0.14 inches below the long-term average. Much of northern Missouri received less than 1 inch, with several northwestern counties reporting less than 0.50 inch. West-central sections reported 0.5-1.5 inches, with much of central, east-central and far southwestern Missouri receiving 1.5-2.5 inches. Heavier totals ranged from 2.5 to 5 inches across southern Missouri.
No winter storms occurred in December, but two unusual severe storm outbreaks affected the Show Me State during the month. The first was a deadly late-season multistate tornado outbreak Dec. 10-11 in Arkansas, Missouri, Illinois, Tennessee and Kentucky. National Weather Service surveys documented six tornadoes in Missouri on the evening of Dec. 10, with two fatalities. A long-track EF4 tornado crossed the Missouri Bootheel from Arkansas and tore through Dunklin and Pemiscot counties. The tornado path was just over a mile wide in places, with estimated peak winds at 170 mph. Many homes were damaged or destroyed, and one fatality was reported in Pemiscot County. Another deadly tornado, with estimated peak winds of 165 mph, affected St. Charles and St. Louis counties in east-central Missouri. The tornado destroyed a couple of homes near Defiance, with one reported fatality.
The second outbreak was on Dec. 15 when an intense low pressure system in Kansas initiated a squall line of severe thunderstorms and tornadoes that swept through portions of Kansas, Nebraska, Missouri, Iowa, Minnesota and Wisconsin. The magnitude and intensity of the event fit the criteria for a derecho, with wind damage extending more than 250 miles and wind gusts of at least 58 mph. This was the first December derecho ever documented in the United States.
Mild late fall/early winter weather translated to state, county and consumer savings associated with reduced heating demand and less stressful conditions for outdoor workers, livestock and pets.
For the year, Missouri experienced eight months with above-average temperatures and four months with cooler-than-average conditions. Preliminary data indicated an annual average temperature of 56.3 F, 1.8 degrees above the long-term average. Nineteen out of the past 24 years have been warmer than average. The statewide average annual precipitation total was 43.94 inches, 3.44 inches above the long-term average.
— MU Extension