Missouri 2014 Growing Season Climate Summary

Pat Guinan
State Climatologist
Commercial Agriculture/University of Missouri Extension

November 4, 2014

With few exceptions, the 2014 growing season was a benign one in Missouri, dominated by seasonable temperatures and sufficient precipitation. Weather conditions were favorable for crops, pastures and livestock as producers began anticipating a bin busting harvest toward the end of summer. One of the biggest hurdles for farmers was a period of extreme wetness in October that halted harvesting opportunities for much of the month. Drier conditions, however, during the latter half of the month allowed harvest to resume by the end of October.

April temperatures in Missouri were near normal this year, but not indicative of the week to week variability that occurred. Roller coaster temperatures impacted the state with alternating periods of warm and cool weather. A late season moderate freeze impacted much of Missouri during the middle of April with some locations experiencing record cold minimums on the morning of the 15th, including Springfield (25°F), Joplin (25°F),Vichy-Rolla (26°F), and St. Joseph (23°F). Vegetative freeze injury was minimized due to dominant cool conditions in March and the first week of April. For the first time in 2014, April precipitation averaged above normal with a statewide average total of just over 5 inches. Nearly 50% of the corn had been planted by the end of April, slightly ahead of the 5-year average.

May temperature trends in Missouri were much like April - erratic with alternating periods of warm and cool weather. It was a seasonably warm month, with an average statewide temperature of 65.3°F, or 1.1°F above normal. Record warmth was reported during the first week of May when high temperatures climbed into the 90s for a couple days. Unusually cold temperatures occurred during the mornings of May 15, 16 and 17 when minimum temperatures dipped into the 30's. Frost damage was reported in some locations, especially low lying areas prone to cold air drainage. May precipitation was variable, but drier than normal for most of the state. The statewide average total was 3.19 inches, or nearly 2-inches below the long-term average. Dry conditions were impacting all of northern, west central and southwestern Missouri toward the end of the month.

Wet conditions emerged during June across much of the Show Me state with statewide average monthly precipitation averaging just over 6-inches, or more than 1.5 inches above normal. Monthly totals varied across the state with northern, western and extreme southeastern sections reporting the heaviest rainfall, ranging from 7-10 inches. The rest of the state received 3-6 inches. An area of residual long-term drought was confined to some southwestern counties by the end of June. June started warm but transitioned to a cool, cloudy period for several days through mid-month. More than half the days were cloudy during the first half of June, but sunny days, and seasonably warm and muggy conditions dominated during the latter half of the month. The average statewide temperature for June was 73.9°F, or 0.6 degrees above the long-term average. Corn, soybean and pasture conditions were looking promising with 79%, 75%, and 58% in good to excellent condition, respectively, by the end of the month.

A persistent northwesterly flow upper air weather pattern resulted in one of the coolest Julys on record for Missouri, and much of the Midwest. The average statewide temperature was 72.6°F, nearly 5 degrees below normal, and ranked as the second coolest July on record for Missouri (1950 was the coolest). Reinforcing shots of Canadian air limited opportunities for Gulf of Mexico moisture to inhabit the region. Accordingly, precipitation events tended to be light and infrequent. The July average statewide precipitation total was 2.59 inches, or about 1.25 inches below the long-term average. Fortunately, cool temperatures during the month mitigated crop and pasture stress in dry areas of the state, though non-irrigated lawns were beginning to turn brown and some farmers were becoming concerned over the extended period of dryness. Surface water resources remained mostly adequate due to below normal evaporation rates.

Temperatures trended cooler than normal during the first half of August, but a hotter weather pattern emerged during the latter half of the month, including a late summer heat wave and some of the highest temperatures for the year. The statewide average temperature was 76.5°, or 0.5 degrees above normal. August rainfall was variable across the Show Me state, ranging from above normal over northern sections, near normal in central, and mostly below normal across southern Missouri. The statewide total was 4.34 inches, or nearly 0.75 inches above the long-term average. As August progressed, northern sections became wetter while southern Missouri turned drier. The Drought Monitor map depicted much of southwestern and south central Missouri experiencing abnormally dry to moderate drought conditions toward the end of the month. August totals generally ranged from 5-8 inches across northern Missouri, 3-5 inches over central sections and the Missouri Bootheel, to 1-3 inches over southern sections.

Below normal temperatures were dominant in Missouri for the first three weeks of September followed by an early autumn warm spell during the last week of the month. Preliminary data indicate the statewide average temperature was 67.2°F, or a little more than one degree below the long-term average. Rainfall was highly variable across Missouri during September, but the statewide average was around 4-inches, which is near the long-term average. Heaviest totals occurred over northern, central, east central and southwestern sections where 4-6 inches were common. Lesser amounts, ranging between 2-4 inches, were reported in west central, south central and southeastern Missouri. There were a couple widespread and significant rainfall events with extensive flooding reported across parts of northern and central Missouri during the month.

Highly variable weather impacted the state during October with unusually heavy rain falling over the state during the first half of the month, followed by little to no rainfall during the latter half. The statewide average total rainfall for the first half of October was just over 6 inches whereas the state averaged a paltry 0.25 inches for the second half of the month. Despite dry conditions during the last two weeks, the statewide average monthly total of 6.25 inches ranks as one of the top ten wettest Octobers on record for Missouri. Harvesting opportunities were halted during the first 3 weeks of the month, but abundant sunshine in combination with mild temperatures, and little to no rainfall during the latter half allowed farmers to resume fieldwork activity by the end of the month. According to the Missouri Agricultural Statistics Service, corn and soybean harvest was 68% and 46% complete, respectively, for the week ending October 27. The first widespread freeze impacted Missouri on October 31, and effectively ended the 2014 growing season.