GRAPHICAL CLIMATOLOGY OF MINNEAPOLIS-ST. PAUL AREA TEMPERATURES, PRECIPITATION, AND SNOWFALL

                                                                                                      (1820-PRESENT)

                 

                                                      By Charles Fisk*        Last Update: 10 June 2008

     

    The following is a graphical climatology of Minneapolis-St. Paul, Minnesota temperatures, precipitation, and snowfall, from the start of 1820 (Fort Snelling) into the present year 2008. Presented are 31 summary overview charts, a link to a year-by-year account of early (1820-1869) Minnesota weather history, followed by 188 year-to-year graphs depicting daily temperatures, precipitation, and snowfall. Original source data are from Fort Snelling (1820-1858), St. Paul Smithsonian recordings (1859-1872); and government weather service observations for St. Paul (1873-1890), downtown Minneapolis (1890-1938), and the Minneapolis-St. Paul International Airport (1938-present).  Daily snowfall totals date from 1891, snow depth data from 1893. 

    Data were obtained from the National Archives, the Minnesota Historical Society, The University of Minnesota Periodicals Library, the National Climatic Data Center, the Minneapolis-St. Paul National Weather Service Office online site, and the Minnesota Climatology Working Group. Monthly updates are from the site: http://climate.umn.edu/doc/prelim_lcd_msp.htm

 

CLIMATE OVERVIEW GRAPHS –

 

TEMPERATURE:

 

   MINNEAPOLIS-ST. PAUL DAILY TEMPERATURES (MEANS & EXTREMES)

 

          COMPLETE YEAR      JAN         FEB        MAR        APR        MAY        JUN        JUL        AUG        SEP        OCT        NOV        DEC   

            

   MINNEAPOLIS-ST. PAUL MONTHLY TEMPERATURES (EXTREMES):   HIGHEST MAXIMA      LOWEST MINIMA      LOWEST MAXIMA       HIGHEST MINIMA             

 

 MINNEAPOLIS-ST. PAUL AVERAGE DAY-TO-DAY VARIABILITY IN MEAN, MAX, & MIN TEMPERATURE, BY CALENDAR DAY  

 MINNEAPOLIS-ST. PAUL AVERAGE DAILY TEMPERATURE RANGES, BY CALENDAR DAY

 MINNEAPOLIS-ST. PAUL STANDARD DEVIATION STATISTICS FOR DAILY MEAN, MAX, & MIN TEMPERATURES, BY CALENDAR DAY

         MINNEAPOLIS-ST. PAUL SKEWNESS STATISTICS FOR DAILY MEAN, MAX, & MIN TEMPERATURES, BY CALENDAR DAY

    MINNEAPOLIS-ST. PAUL ANNUAL MEAN TEMPERATURE HISTORY (1820-2007)     

 

   PRECIPITATION:

 

        MINNEAPOLIS-ST. PAUL YEARLY PRECIPITATION HISTORY (1891-2007)  

  MINNEAPOLIS-ST. PAUL AVERAGE MONTHLY PRECIPITATION  

   MINNEAPOLIS-ST. PAUL PRCP-DAY FREQUENCIES FOR >=0.01", >=0.13", >=0.25", >=0.50", & >=1.00" MAGNITUDES, BY CALENDAR DAY (1891-2007)

           MINNEAPOLIS-ST. PAUL MONTHLY PRECIPITATION DISTRIBUTIONS (BOXPLOTS)              

 

   SNOWFALL:

    

    MINNEAPOLIS-ST. PAUL SEASONAL SNOWFALL HISTORY (1884-85 THRU 2007-08 SEASONS)                

   MINNEAPOLIS-ST. PAUL AVERAGE MONTHLY SNOWFALL  

   MINNEAPOLIS-ST. PAUL MONTHLY SNOWFALL DISTRIBUTIONS (BOXPLOTS)

   MINNEAPOLIS-ST. PAUL ONE AND THREE-INCH SNOW-DAY PROBABILITIES, BY CALENDAR DAY

           MINNEAPOLIS-ST. PAUL MEDIAN, MEAN, AND EXTREME MAXIMUM SNOW DEPTHS, BY CALENDAR DAY    

  

 

   YEAR-BY-YEAR ENCYCLOPAEDIC ACCOUNT OF EARLY MINNESOTA WEATHER (1820-1869)

                  

 

   THE HISTORICAL TEMPERATURE DATA: OFFICIAL WEATHER BUREAU OBSERVATIONS (1873-PRESENT) AND RECONSTRUCTED PIONEER ERA

    RECORDINGS (1820-1872)

                                                    

  Temperature graphs for the 1873-present period are based on official St. Paul or Minneapolis absolute maximum and minimum temperature observations for given days (nearly all for the midnight-to-midnight period), the standard method of recording "summary-of-the-day" temperature statistics for first-order weather stations. 

  Original summary-of-the-day temperature observations for the 1820-1872 “Pioneer” era (along with those for cloudiness, wind direction, and wind force), however, consisted of fixed-time scheme observations according to a prescribed format (e.g., 7AM, 2PM, and 9PM; or Sunrise, 9AM, 3PM, and 9PM) (example 1) (example 2).

  To achieve methodological consistency, the fixed-time-scheme 1820-1872 observations were converted into midnight-to-midnight maxima and minima approximations, using application of 1961-1980 statistical relationships between Minneapolis-St. Paul Airport temperature, cloudiness, and wind information at hours corresponding to the old fixed-time schemes, and 1961-1980 midnight to midnight daily temperature maxima and minima [Fisk, 1984]. This reconstruction “homogenized” the entire history as to summary-of-the-day method, and affords identical-type daily temperature graphs to be presented here for the entire 1820-present history ADD'L DETAILS ON RECONSTRUCTION OF MINNEAPOLIS-ST. PAUL AREA PIONEER-ERA TEMPERATURE RECORD.

    

 

     YEAR-TO-YEAR GRAPHS - INTERPRETATION

 

    The uppermost chart on a given yearly page (links below) are “floating-bars” of the daily maxima and minima. Superimposed are two line traces, the upper one connecting average daily maxima, the lower one average daily minima.  The bars depict the varying diurnal, synoptic, long-wave, and seasonal influences on temperature over time, and subjectively, some years’ patterns can be quite interesting to look at (see “REPEAT LINKS TO SOME OF THE MORE INTERESTING YEARS WITH ACCOMPANYING NOTES” section below).       

   The second chart down shows the arithmetic departures of day-to-day mean temperatures (sum of the daily maximum plus the daily minimum divided by two) less the corresponding calendar-day average means.  Vertical lines extending upward from the zero line indicate above average means for the day (colored red), those extending downward indicate below average daily means (colored blue).  In the entire series of more than 68,000 days, greatest positive departure for any individual day is +38 F for 25 January 1944, the greatest negative departure -45 F for 1 January 1864.

 

1820  1821  1822  1823  1824  1825  1826  1827  1828  1829  1830  1831  1832  1833  1834  1835  1836  1837  1838  1839       

1840  1841  1842  1843  1844  1845  1846  1847  1848  1849  1850  1851  1852  1853  1854  1855  1856  1857  1858  1859    

1860  1861  1862  1863  1864  1865  1866  1867  1868  1869  1870  1871  1872  1873  1874  1875  1876  1877  1878  1879

1880  1881  1882  1883  1884  1885  1886  1887  1888  1889  1890  1891  1892  1893  1894  1895  1896  1897  1898  1899

1900  1901  1902  1903  1904  1905  1906  1907  1908  1909  1910  1911  1912  1913  1914  1915  1916  1917  1918  1919

1920  1921  1922  1923  1924  1925  1926  1927  1928  1929  1930  1931  1932  1933  1934  1935  1936  1937  1938  1939

1940  1941  1942  1943  1944  1945  1946  1947  1948  1949  1950  1951  1952  1953  1954  1955  1956  1957  1958  1959

1960  1961  1962  1963  1964  1965  1966  1967  1968  1969  1970  1971  1972  1973  1974  1975  1976  1977  1978  1979

1980  1981  1982  1983  1984  1985  1986  1987  1988  1989  1990  1991  1992  1993  1994  1995  1996  1997  1998  1999

2000  2001  2002  2003  2004  2005  2006  2007  2008

 

    The third chart down shows chart two’s departures in deseasonalized or “standardized” form. This adjusts for the fact that individual calendar days have higher or lower inherent year-to-year variability in daily mean temperature. For example, standard deviations of given calendar-day daily mean temperatures for the 1820-2006 period ranged from 14.87 F (4 February) to 5.48 F (21 August). Dividing a given day’s departure from average by its’ respective calendar day daily mean temperature standard deviation creates the standardized departures or “z-scores”.  Only five daily departures in the entire series are plus or minus 3.5 or greater. Three of these, all negatives, came over the four-day period 4-7 November 1991, associated with an unseasonably cold arctic air outbreak in the wake of a record early and heavy snowstorm.

    The fourth chart down depicts daily rainfall, the fifth and sixth charts, respectively, daily snowfall and snow depths.   

      

                   

         REPEAT LINKS TO SOME OF THE MORE INTERESTING YEAR-TO-YEAR GRAPHS, WITH ACCOMPANYING NOTES

 

 

1820 -  Year One. Frigid January WEATHER DIARY FOR JAN 1820, very mild April, eleven-inch snowstorm in mid-October.

 

1822 -  Coldest December in history DEC 1822; December 2nd 42 F below average. Also torrential June rains,  producing local flooding JUN 1822.

 

1824-1825 – (July-June view). Exceptionally mild December ‘24 to April ’25 period; likely El Nino influence.

 

1826 -  Very backward April APR 1826 (accompanied by severe flooding), but May 28 F warmer than April. 

 

1829  - “The Dry Year”, as described by early Minnesota history texts. Severely cold February and other extreme temperature spells throughout year.

 

1830 -  Hottest July until 1936, and much above normal October/November.

 

1833 -  El Nino winter of ‘32-’33 mildest for another 45 years. Very mild December ’33 also.

 

1833-34 - (July-June view). Greatest three-month thermal “see-saw” in history: January 1834 29 F colder than December 1833, February 1834 28 F warmer than January.  

         

1835   -  Volcanic dust-veil produces series of anomalous cold spells during second half.

 

1838   -  Great temperature extremes. Minus 40 F in February and a late May hard freeze. Hot summer, but unseasonable cold in fall and early winter.

 

1838-39  - (July-June view). Abnormal cold over October to December ’38 gives way to abnormal warmth over January to April ‘39.

 

1839 - Warmest recorded year up to this time; warmest April APR 1839 down to the present day.

       

1842 - Extraordinary coolness over mid-May into July. Coldest June JUN 1842 and coldest November NOV 1842 in all history down to present.

 

1843 -  Coldest year in area history. Extraordinary persistent arctic cold over February and March. Coldest March (more than 25 F below average) MAR 1843, and coldest October OCT 1843 in all history down to present.

 

1842-43 - (July-June view).

 

1845   -     Steep temperature plunge over mid-to-late November.

 

1846 -  Warmest year of pre-statehood era. Mildest January in all history down to the present JAN 1846.

 

1849 -  December 34 F colder than November.

 

1855-56 – Two successive arctic blasts, in late December DEC 1855 and early January JAN 1856.  A third in February. 

 

1857 -  Second successive bitter winter. Coldest January JAN 1857 and April APR 1857 in history.

 

1863 -  The “Strange” weather year. Extremes in temperatures, and worst growing season drought to date - no measurable rain in June (St. Paul). Killing frosts in July and August across settled areas.

 

1864  -  Continued drought during the year. Frigid New Years’ Day – Maximum: -24 F, Minimum: –38 F in St. Paul.        

 

1865 -  Heavy summer rains break drought; 38” recorded for year in St. Paul, more than ’63 and ’64 combined. Very cool summer, July 1 F cooler than September. 

 

1867 -  Very backward spring. March 1867 5 F colder than any March since, but still 8 F warmer than 1843. More than 10” rain in June in St. Paul.

 

1869   - More than 18” rain over August and September.

 

1875 -  Second coldest year in history. January and February both AVERAGE below zero.

 

1877-78 - “Year Without a Winter”. El Nino-induced extraordinarily mild winter. Mildest December in history. Near record warmest February and March.

 

1879 -  Second Edition of Summer” brings unseasonable October warmth. Very cold Christmas Day, minus 39 recorded in St. Paul. 

 

1885   - Great temperature variability over January to March.

 

1888 -  Severe winter (including –41 F in January). Persistent spells of unseasonable coolness into spring and summer.

 

1895   -  Abrupt May cold turn temporarily derails an otherwise forward Spring.

 

1899   -  Great February cold wave.

 

1907   -  Persistent abnormal cold through April and May; 13” snowstorm over Apr 27-28.

 

1910 -  Driest year (11.54”) in local climatic history down to present. Also warmest March in all history. 

 

1911 -  Great adjacent-year reversal in annual precipitation – Wettest year (40.15”) in all history down to present. 

 

1915 -  Very forward April, but May 4 F colder; very cool summer ensues.

 

1917 -  Coldest year of 20th Century. Deep Snows – 31” depth on 16 March.

 

1921 -     Warmest year since 1878.

 

1923   -  Very cold March, very mild November-December.

 

1930    - Sharp temperature gyrations over latter part of year.

 

1931 -  Warmest year in history down to the present; 104 F recorded in September.

 

1933   -  Warmest June in history. 77 F on 1 November

 

1934   In midst of Dust Bowl era. Warmest May in history, including 106 F on the 31st. June registers a 104 F day, three days in July record 105 F. 

 

1936   Great temperature contrasts between winter and summer. Thirty-six consecutive days with subzero minima over January and February (including –34 F in January). Hottest July on record; 108 F recorded on 14th for highest in history. Also recorded in July: 106 F three times, 105 F and 104 F once each.

 

1940   Great Armistice-Day Blizzard leaves nearly 17 inches’ snow over 11th-12th.

 

1942   Highly irregular temperature anomaly pattern over course of year.

 

1945   Very forward early spring, then very cool through early summer.

 

1947   Warmest August AND October in all history down to the present.

 

1948    - March temperature range –27 F to 70 F (97 F spread highest ever for a single calendar month locally).

 

1951   40” snowfall in March.

 

1953-54 – Quasi-periodic much above normal spells over late-August through February. February ‘54 warmest since 1878. 

 

1958    - Driest year (16.20”) since 1910.

 

1959   December 5 F warmer than November.

 

1962   -   Deep snows in late February and early March; minus 32 F on 1 March.

 

1965 -  Coldest March since 1899; coldest September since 1868.

 

1967   -  35.3” snowfall in January; 30” snow depth on 19 February.

 

1972    -  Coldest year since 1917.

 

1976-77 – Twentieth century approximate version of 1838-39. Abnormally cold October-January, unusually warm February-May.

 

1982    -  46.4” snowfall in January, 38” snow depth on 23 January. 1981-82 season sets new snowfall record (95.0”) – only to last two seasons, however.

 

1983 -  Wettest year (39.07”) since 1911. Very mild January to early March, a warm summer, but coldest December since 1831. 21.8” snowfall in April – a new high mark for that month. 

 

1983-84  - Snowiest winter in history (98.4”).

 

1985    - Unusually mild March and April, cold November-December.

 

1987 -  Second warmest year in history. Steady above average warmth throughout virtually the whole year. July wettest calendar month in local history (17.90”).

 

1988 -  Drought year. Very hot summer, 105 F in July.

 

1991   -  Great early snowstorm drops 27” over 31 Oct and 1 Nov followed by unseasonably early arctic outbreak; 46.9” total snowfall for November, snowiest calendar month in recorded history. 

 

1992 -  Very mild winter. Very cool summer (possibly induced by Mt. Pinatubo eruption); Coolest July since 1865.

 

1996    -  Great arctic outbreak in late-January/early February.

 

1997-98  - El Nino-induced, very mild ‘97-‘98 winter.

 

2000   -  Very mild March, very cold December.

 

2001 -  Wettest April on record (7.00”). Warmest November in history by more than 4 F. Fifty-seven consecutive above normal temperature days from late October to late December.

 

2001-02   -  Mildest November-February period in all history by nearly 2 F.

 

2006 – Third warmest year in all history. Warmest January since 1846; warmest July since 1936.

 

 

*Member, American Meteorological Society     

               

     Vitae               

                                                                          

                                                              mailto:cjfisk@worldnet.att.net         

 

 

 

Link to Graphical History of Chicago Daily Temps &  Precip., (1870's to Present) 

 

Graphical History of Downtown Los Angeles Daily Temps and Rainfall (1921-Present)

 

Link to Graphical History of New York Central Park Daily Temps, Precip, and Snowfall (1876-present for temps)