MINNEAPOLIS-ST. PAUL AREA DAILY CLIMATOLOGICAL HISTORY
OF TEMPERATURE, PRECIPITATION,
AND SNOWFALL, A YEAR-BY-YEAR GRAPHICAL PORTRAYAL
(1820-PRESENT)
By Charles Fisk*
The following series of links comprise a
year-by-year visual time-series history of Minneapolis-St. Paul area daily
temperatures, precipitation, and snowfall, from the beginning of continuous
daily record keeping at old Fort Snelling in 1820 to present day observations
at the Minneapolis-St. Paul International Airport. The graphs can be used for
historical reference, descriptive climatology, or browsed for their own sake.
The history includes more than 38 years’ observations through early 1858 at
Fort Snelling, another 14 years of St. Paul Smithsonian Institution volunteer
recordings (1859-1872), followed by a century-and-a-quarter of government
weather service observations in St. Paul (1873-1890), downtown Minneapolis
(1890-1938), and the current Minneapolis-St. Paul Airport location
(1938-present). The current year’s graph is updated monthly. Preceding the
year-to-year graphs are a set of eleven summary overview charts, plus a link to
year-by-year accounts of early Minnesota weather history for the 1820-1869 era.
- GRAPH TYPES DISPLAYED
Six types of graphs are presented: 1) daily maximum and minimum
temperatures, 2) daily mean temperature departures from “normal” (daily mean
temperatures less climatological mean temperature for the day), 3) standardized
daily temperature departures from average (departure statistics of (2) divided
by the standard deviation of daily means for the day), 4) daily precipitation
totals (from 1836), 5) daily snowfall totals (from 1891), and 6) daily snow
depths (from 1893).
- THE DATA: OFFICIAL WEATHER BUREAU
OBSERVATIONS AND RECONSTRUCTED PIONEER ERA RECORDINGS
Temperature
graphs for the 1873 to present period are based on official St. Paul or
Minneapolis weather bureau observations of twenty-four hour absolute maximum
and minimum temperatures for a given day (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
daily temperature statistics for the 1820-1872 “Pioneer” period consisted of
fixed-time scheme temperature observations, along with those of sky cover and
wind direction/force, according to a prescribed format (for example: at 7AM,
2PM, and 9PM; or Sunrise, 9AM, 3PM, and 9PM). To conform to the
first-order-station temperature observation method, “homogenize” the entire
record in this regard, and in the process permit identical-type day-to-day
temperature graphs throughout, the 1820-1872 daily observations were
transformed into midnight-to-midnight maxima and minima estimates. This
was accomplished by application of statistical models that defined 1961-1980
empirical relationships between Minneapolis-St. Paul Weather Service Office
temperature, cloudiness, and wind information at hours corresponding to the old
fixed-time schemes, and 1961-1980 midnight to midnight temperature maxima and
minima [Fisk, 1984]; see http://climate.umn.edu/pdf/Fisk_thesis.pdf.
ADD'L DETAILS ON
RECONSTRUCTION OF MINNEAPOLIS-ST. PAUL AREA PIONEER-ERA TEMPERATURE RECORD
- HETEROGENEITY
OF THE CONSOLIDATED RECORD
In
addition to the use of statistically estimated daily maxima and minima for the
first 53 years, the temperature series presented here reflect differing
exposure techniques (e.g., open-air for the thermometers in the pre-weather
bureau era), varying instrumentation qualities, site relocations, and
environmental changes associated with urbanization.
The Minneapolis-St. Paul area data are
based on materials originally 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 based on data from the site: http://climate.umn.edu/doc/prelim_lcd_msp.htm
The uppermost chart on a given
yearly page are “floating-bars” of the daily maxima and minima. Each bar
represents an individual day’s temperature range. 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 on a subjective basis, the features for some years
can be quite striking (see “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 nearly
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.
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 inter-year
variability in mean temperature. For example, inter-year variability (or standard deviations) of same-day
daily mean temperatures for the 1820-2006 period ranged from 14.87 F (4
February) to 5.48 F (21 August). Dividing by these calendar day standard
deviations deseasonalizes the arithmetic departures, and creates the
standardized departures or “z-scores”. Anomalies of greater than or equal to
2.0z (both positive and negative) are observed about 4.0% of the days (or about
15 such events on average over the course of a year); those of plus or minus
2.5 or greater occur on about 0.8% of the days; or minus 3.0 events just 0.1%. 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, showing daily snowfall and
snow depths.
DAILY MAX/MIN
TEMPERATURE CLIMATOLOGY FOR MINNEAPOLIS-ST. PAUL (1820-2006)
AVERAGE DAY-TO-DAY
VARIABILITY IN MEAN, MAX, & MIN TEMPERATURE, BY CALENDAR DAY (1891-2006)
AVERAGE DAILY
TEMPERATURE RANGES, BY CALENDAR DAY (1891-2006)
STANDARD DEVIATION
STATISTICS FOR DAILY MEAN, MAX, & MIN TEMPERATURES, BY CALENDAR DAY
(1891-2006)
SKEWNESS
STATISTICS FOR DAILY MEAN, MAX, & MIN TEMPERATURES, BY CALENDAR DAY
(1891-2006)
ANNUAL MEAN TEMPERATURES FOR MPLS-ST. PAUL AREA, BY YEAR
(1820-2006)
DAILY PERCENT
FREQUENCIES OF >=0.01 in., >=0.25 in., AND >=1.00 in. PRECIPITATION
(1891-2006)
ANNUAL PRECIPITATION FOR MPLS-ST. PAUL, BY YEAR (1891-2006)
TOTAL SNOWFALL FOR MPLS-ST. PAUL, BY SEASON (1884-85 TO PRESENT)
DAILY PERCENT
FREQUENCIES OF >= 1 in. and >= 3 in. SNOWFALLS (1892-93 THROUGH 2005-06
SEASONS)
DAY-TO-DAY
MEDIAN, MEAN, AND RECORD MAXIMUM SNOW DEPTHS (1893 THRU 2005-06 SEASONS)
Year-by-Year Encyclopaedic Account of Minnesota Weather (1820-1869)
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
- LINKS TO SOME OF THE MORE
INTERESTING YEARS 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 hard freeze in late May. 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 persistent coolness
over mid-May into July (June snow observed back East in Cleveland). 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 sieges over late December DEC 1855 and early January JAN 1856. Another 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 in area history up to this point - 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, however, 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
– Very
visual quasi-periodic much above normal spells over late-August through
February. February ‘54 a near record warmest.
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 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
Last Update: 2 May 2007
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)
