April 2021 Weather and Its Impacts on Missouri
University of Missouri Extension
Periods of warm and cool weather were the trend in April with weeks 1 and 4 averaging above normal and weeks 2 and 3 below average, Figure 1. Preliminary data indicate a statewide average temperature of 54.5 °F, or 1.1 degrees below the baseline period mean (1901-2000). Three out of the past four Aprils have been cooler than average, Figure 2, and it was the second below average month for the year, Figure 3.
An unusually cold weather event on the 21st and 22nd of the month brought sub-freezing temperatures to the state, Figure 4, including record low temperatures. Freeze damage was reported to vegetation in vulnerable growth stages, including some early planted corn in southeastern Missouri, as well as some fruit crops, ornamentals and annuals. Lodging of forage crops was also reported, Figures 5 and 6.
Preliminary data for April indicates above average precipitation with an annual statewide total of 4.67 inches, or 0.67 inches above the baseline period mean (1901-2000), Figure 7. Mostly wet conditions have impacted Missouri for the year with 3 out the past 4 months reporting above average precipitation, Figure 8.
Regionally, heavier April precipitation totals were reported across central, northeast and far southern Missouri where 4-6 inches were common. Lighter amounts, ranging from 1.5 to 3-inches, were typical across far north central and northwestern Missouri, according to radar estimates, Figure 9. Similar lighter totals were reported in a handful of southwestern border counties, namely, Jasper, Barton and Vernon Counties.
An unusual late spring snow event impacted Missouri on April 20-21. Accumulations were generally 1-5 inches statewide, Figure 10, occurring mostly on elevated and grassy surfaces. A surreal landscape transpired during the day of April 20 with snow accumulating on flowers, leaves, and verdant lawns, Figures 11-13.
According to the Missouri Agricultural Statistics Service, for the week ending April 25, corn planting was 23% complete, 21 percentage points behind the 5-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%).
As of April 27, 2021, the U.S. Drought Monitor map indicated no drought in Missouri, Figure 14. A tiny sliver of abnormally dry conditions were indicated in far northern Missouri, on the Iowa border, in northern Putnam and Schuyler Counties.
Figure 5. Alfalfa lodging in Christian County, Missouri, April 21, 2021.
Photo by: Tim Schnakenberg
Figure 6. Rye lodging in Christian County, Missouri, April 21, 2021.
Photo by: Tim Schnakenberg
Figure 10. Snowfall reports (in), April 20-21, 2021, NWS & CoCoRaHS observations
Figure 11. Columbia, Missouri, April 20, 2021. Photo by: Pat Guinan
Figure 12. Columbia, Missouri, April 20, 2021. Photo by: Pat Guinan
Figure 13. Columbia, Missouri, April 20, 2021. Photo by: Pat Guinan
Source: Pat Guinan, 573-882-5908