We’ve had some cold weather in Missouri recently. St. Louis hit -6°F on New Years Day, while Kansas City hit -11°F. But these are not records. The record low on New Years day is -10°F in St. Louis, and -13°F in Kansas City.
Kansas City’s all-time record low is -23°F, which occurred in December 1989.
Figure 1 shows a chart for each winter (December, January, and February). Blue columns are the number of days with a low temperature at or below 0°F in St. Louis, and they run from 1874 to 2016. Red columns are for Kansas City, and they run from 1888 to 2016. The dashed blue line represents the trend over time for St. Louis, the dashed red line for Kansas City. You can see that the number of days varies widely from year-to-year. Many years have 1 day, or even none. In St. Louis the maximum number of days was 18, and it occurred in the winter that began in December 1935. In Kansas City, the maximum number of days was 19, and it occurred twice: in 1935 and 1978.
The trend lines show that in Kansas City, the number of days has not been changing over time. In St. Louis, however, the number of days has decreased over time.
(Click on figure for larger view.)
One can count the number of winters that had 0 days below 0°F, the number of winters that had 1 day, the number of winters that had 2 days, etc. You can then construct a frequency chart of how many years had each number of days. Figure 2 shows such a frequency chart for St. Louis and Kansas City. There have been 54 winters in St. Louis when there were no days with lows at or below 0°F, there have been 28 such winters in Kansas City, and no other number is represented in more years than that.
The number of extremely cold days varies widely from year-to-year, but in St. Louis the average number is 3, and in Kansas City it is 4. St. Louis has experienced 2 days below 0°F this winter, and Kansas City has experienced 4 (both as of 1/16). For comparison, St. Louis has had more than 2 days below 0°F some 51 times since 1874. Kansas City has had more than 4 days below 0°F some 31 times since 1888.
The severe cold began this year on the morning of New Years Day. What about last year? Was it a hot one, or not so hot? The next post will review average temperatures for all of 2017.
National Weather Service, Kansas City Forecast Office. 2018. WFO Monthly/Daily Climate Data. Data viewed online 1/15/2018 at http://w2.weather.gov/climate/getclimate.php?date=&wfo=eax&sid=MCI&pil=CF6&recent=yes&specdate=2017-12-31+11%3A11%3A11.
National Weather Service, St. Louis Forecast Office. 2018. Ranked Occurrences of Temperature <= 32 and 0 Degrees (1893-Present). Downloaded 1/15/2018 from http://www.weather.gove/lsx/cli_archive. (Actually contains data back to 1874).
Personal communication from Spencer Mell, Climate Focal Point, National Weather Service, Kansas City Forecast Office.