The following is a Public Information Statement issued by the 
National Weather Service, Great Falls MT
 1130 AM MDT Mon Oct 26 2020:
 

 There have been records set in many categories including warmest 
and coolest maximum and minimum temperatures, winds, precipitation and 
snowfall, snow on the ground and pressure values. Several coldest 
so early in the season records were also set. It is also notable that 
the heavy snow of late October came on the heels of an extended dry 
period across the region. 
 
 Of note for the state, there has been a wide range of temperatures
 for the month. A station at Little Bighorn recorded 90F on the
 sixth, while values of -29F occurred at Potomac and Ringling on the
 25th and 26th. This 119F range is the second largest for October,
 second only to 1935 when a high of 91F (Haugen) and low of -30F
 (Summit/Marias Pass) resulted in a range of 121F.
 
 Temperature...
          Record type   Location  New Record      Old Rec  Yr Set
 Oct 4....High Max      Bozeman Apt  82      Tied    82      1970
          High Max      Helena       84              82      1970
 Oct 6....High Min      Choteau      55              52      1971
          High Min      Stanford     52              51      2006
 
          High Max      Bozeman Apt  82      Tied    82      1960
          High Max      Helena       84      Tied    84      1960
 Oct 7....High Max      Bozeman Apt  80      Tied    80      1980
          High Max      Helena       80      Tied    80      1889
 Oct 8....High Max      Helena       82      Tied    82      1910
 Oct 18...Low Max       Bozeman Apt  32              33      1949
          Low Max       Cut Bank     20      Tied    20      1949
                        Tied for third earliest 20F or cooler max 
                        temp
 Oct 22...Low Max       Bozeman Apt  27              34      1961
          Low Max       Cut Bank     25              26      1957
          Low Max       Dillon       30              34      1961
          Low Max       Great Falls  20              28      1957
          Low Max       Havre        22              28      1893
          Low Max       Lewistown    20              24      2002
 
          Low Min       Bozeman Apt  15              16      1961
          Low Min       Dillon       13              15      1981
          Low Min       Great Falls   5               8      1917
          Low Min       Havre         3               8      1881
 Oct 23...Low Min       Bozeman MSU   8              10      1919
          Low Min       Cut Bank      5               6      2012
          Low Min       Dillon        7              12      1984
          Low Min       Great Falls   3              10      1957
          Low Min       Havre        -5               8      1919
          Low Min       Fresno Reservoir and north of Chinook
                                    -11
                        This is the eighth earliest of record for
                        a low of -10F or cooler in MT (since 1892).
                        Average for this event is November 13.
          Low Max       Bozeman Apt  28              30      1957
          Low Max       Cut Bank     16              17      1957
          Low Max       Great Falls  16              21      1957
                        Third earliest 20F or cooler max temp
 Oct 24...Low Min       Bozeman Apt   4               6      1975
          Low Min       Cut Bank    -10              -4      1919
                        Earliest of record -10F or cooler min temp.
                        Old record was October 25 1919.
          Low Min       Dillon        5              14      2002
          Low Min       Lewistown    -4              -1      1919
 
          Low Max       Bozeman Apt  23              31      1975
          Low Max       Cut Bank     14              18      1919
          Low Max       Dillon       24              31      1997
          Low Max       Lewistown    20              21      1919
 
          The high temperature of 15 at Great Falls on the 24th did
          not set a new record, as it was 14F for a high temperature
          in 1919. It did tie for the earliest high temperature of
          15F or cooler.
 Oct 25...Low Min       Bozeman Apt -14               9      1961
                        Earliest of record -10F or cooler min temp
          Low Min       Dillon       -6              11      2002
          Low Min       Helena       -4               0      1919
                        Second earliest subzero temp of record
          Low Min       Lewistown    -6              -1      1919
          Low Min       Ringling    -25             
                        Previous record for this date in MT was   
                        -21 at Shelby in 1919. This was the third
                        earliest that a -20F or colder temperature
                        was recorded in MT. The earliest was Oct 21
                        2009 at Placer Basin SNOTEL and the second
                        was at Babb on Oct 24, 1919. The average
                        for this event is November 24. Potomac
                        fell to -29 this morning.
          Low Max       Bozeman Apt  13              29      1969
                        This high temperature was the earliest in
                        the season for a maximum temperature of 15F
                        or colder. The record was October 29, 2019.
          Low Max       Bozeman MSU  15              22      1969
          Low Max       Dillon       13              28      1939
                        This high temperature was the earliest in
                        the season for a maximum temperature of 15F
                        or colder. The record was October 29, 2019.
          Low Max       Great Falls  14              17      1919
          Low Max       Helena       14              20      1919
                        This high temperature was the earliest in
                        the season for a maximum temperature of 15F
                        or colder. The record was October 27, 1925.
          Low Max       Lewistown    10              21      2012
                        This high temperature was the earliest in
                        the season for a maximum temperature of 15F
                        or colder. The record was October 28, 1971
                        and 1991. It was also the earliest for a
                        high temperature of 10F or colder. The
                        record was October 28, 1991.
          Low Max       W Yellowston 21              26      1975
 Oct 26...Low Min       Bozeman Apt -14              11      2002
                        All-time coldest for October. Previous was
                        -14F Oct 29 and 30, 2019.
          Low Min       Dillon       -9              14      2011
          Low Min       Havre        -3               3      1919
          Low Min       Helena       -6               6      1919
                        Second earliest subzero temp of record
          Low Min       Lewistown    -5               1      1923
          Low Min       Ringling    -29             
                        Previous record for this date in MT was   
                        -16 at Wibaux in 1919. This tied for the 
                        second coldest temperature recorded in MT 
                        in October, and the coldest since -30     
                        occurred at Summit/Marias Pass Oct 31 1935.
                        This would be the third coldest temp observed
                        in the lower 48 states in October. The 
                        coldest is -33F at Soda Butte, WY on Oct 29
                        1917.
          Low Min       W Yellowstn -22              -4      1975
                        This value ties the all-time lowest October
                        temperature at West Yellowstone. The record
                        is -22F on October 22, 1923.
               
        
 Wind...
 Oct 10...High Pk Gust  Bozeman      42 mph          37      1995
          High Pk Gust  Dillon       53 mph          45      2007
 Oct 12...High Pk Gust  Bozeman      49 mph          40      1980
          High Pk Gust  Dillon       46 mph          37      1980
          High Pk Gust  Helena       57 mph          45      2007
          High Day Avg  Bozeman     17.7 mph        12.0     1954
                        Seventh highest daily average for October
                        and highest in October since 2017.
 Oct 13...High Pk Gust  Dillon       59 mph          52      1971
                        Third highest gust of record for October.
          Winds 700 mb  Great Falls  76 kts  at 6 pm
                        Second highest winds at 700 mb for October.
          Winds 200 mb  Great Falls 162 kts  6 pm   140 kts  
                        Highest winds at 200 mb for October. Old
                        record is 140 kts Oct 31, 1994. Highest
                        for any time of year is 164 kts Jan 16 2011
                        and Jul 31 1961.
 Oct 14...High Pk Gust  Helena       57 mph          40      1991
          High Pk Gust  Lewistown    49 mph  Tied    49      2016
          High Day Avg  Helena      18.4 mph        17.0     1991
 
 
 Precipitation/Snow...
 Oct 17...High Day Pcp  Helena       0.63 in        0.53     1916
          High Day Snw  Great Falls  4.2  in        1.7      1961
          High Day Snw  Helena       6.6  in        5.0      1866
 Oct 18...High Day Snw  Great Falls  8.2  in        3.4      1949
                        This was also the greatest for any 
                        calendar day in October. Previous record
                        was 6.6 inches on Oct 13, 1975.
          High Day Pcp  Great Falls  0.69 in        0.43     1979
 Oct 17-18 2-day snow   Great Falls 12.4  in        8.3      1957
                        Highest for any two-day period in Oct.
                        Seventeenth highest overall.
 Oct 21...High Day Snw  Havre        4.4  in        1.7      1961
 Oct 22...High Day Snw  Bozeman MSU  5.6  in        5.0      1975
 Oct 23...High Day Snw  Great Falls  4.0  in        2.8      1954
          High Day Snw  Helena       8.7  in        3.6      1919
 Oct 24...High Day Snw  Bozeman MSU  7.0  in        3.6      1997
          High Day Snw  Great Falls  7.0  in        3.1      1984
          High Day Snw  Havre        1.6  in  Tied  1.6      1898
          High Day Snw  Helena       8.9  in        6.8      1969
 Oct 23-24 24-hr snow   Helena      17.6  in       14.0      1891
                        Highest 2-day total for October, too.
                        This is the 5th highest 2-day total for
                        any time.
 October..High snowfall Great Falls 28.0  in       18.5      1925
                        Eighth snowiest any month of record.
          High snowfall Bynum 4SSE  33.3  in       16.6      1975
          High snowfall Choteau     24.4  in       21.0      1975
                        Seventh highest for any month.
          High snowfall Stanford    21.0  in  Tied 21.0      1975
          High snowfall Loma        20.7  in       11.0      1984
          High snowfall Cut Bank    20.9  in       17.5      1934
          High snowfall Fort Benton 17.3  in       13.0      1951
 
 The 8-day period from October 17-24 produced 26.8-inches of snow at
 Great Falls. This is the snowiest 8-day period on which snow fell
 every day. The snowiest 8-day period was Apr 23-30, 2009 when 28.5-
 inches of snow fell on 7 of the days.
 
 Areas in south and west Helena reported 20+ inches in the storm
 from October 23-24. This was one of the heaviest snows in the Helena
 area since the 1960s.
 
 Pressure
 Oct 24...High daily    Bozeman     1040.3 mb    1039.3     2003
                        Sixth highest value for October.
          High daily    Dillon      1036.9 mb    1034.8     1965
          High daily    Great Falls 1042.8 mb    1038.1     1969
                        Second highest value for October.
          High daily    Havre       1041.0 mb    1036.0     1969
                        Third highest value for October.
          High daily    Helena      1042.5 mb    1038.0     2003
                        Second highest value for October.
 
 Days with measurable snow
 Great Falls recorded 9-days, which ties the record last set in 1984.
 
 Days with 3-inches or more of snow
 Great Falls recorded 4-days, which set a new record. The old record
 was 3-days in 1975.
 
 Snow on ground
 Great Falls had 10-inches on the ground on the 19th. This exceeded
 the previous record depth for October of 7-inches set in 2019.
 Previously, the earliest date with 10-inches on the ground was
 November 9, 2012. Average for this event is January 7, with it not
 occurring in 18 of the last 30 years.
 
 Helena measured 11-inches on the ground on the 24th. This exceeded
 the previous record depth for October of 10-inches in 1925. The
 earliest for this event was September 28, 1965. It has only occurred
 in seven of the last 30 years.
 
 Freeze-free period
 Since the first freezing temperature at Great Falls on September 8,
 the next freezing temperature was on October 13. The freezing
 temperature on September 8 was their sixth earliest of record and
 gave a freeze-free season of 107 days...the 9th shortest of record.
 
 For first freezes much earlier than the average - such as this
 year, it is not uncommon for the next to be closer to, and after
 the seasonal average. The 1981-2010 seasonal average at Great Falls
 is September 20. Of the 28-years in which freezing temps occurred
 on or before September 15 at Great Falls, the average date for the
 next freezing temp is 16-days later. This year, the second freeze
 date on Oct 13 was 35-days later. This is the second longest of
 record between the first and next freezes with the longest being a
 46-day period between the first and subsequent freezing temps in
 1962. Then, the first freeze was September 7 and the next was
 October 23. The third longest such stretch was 33-days in 1956.
 
 Even in the earliest freeze at GTF (Aug 22, 1992), there were 4-
 days of freezing mins, with the next freezing min on Sep 6.
 
 
 
 Extended dryness before the snow...
 
 Dillon...
 A 315-day period with no more than 6-inches of accumulated
 precipitation ended on October 10. This was the longest such period
 since a 331-day period ending April 14, 2013. The record is 408-days
 ending January 1967.
 
 Great Falls...
 A 36-day period of no more than a trace of precipitation occurred
 between September 8 and October 13. This is the 12th longest with
 no more than a trace and longest since 2012. The record is 62-days.
 
 Also, a 98-day period of no more than one-inch accumulated
 precipitation occurred between July 11 and October 16. This is the
 26th longest of no more than one-inch of precipitation and longest
 since 2019. The record is 188-days.
 
 Helena...
 A 108-day period of no more than three-quarters of an inch
 accumulated precipitation occurred between June 30 and October 15.
 This is the 20th longest of no more than three-quarters inch and
 longest since 2004. The record is 165-days.
 
 
 
 Records for Bozeman began in 1935...Cut Bank began in 1903...Dillon 
 began in 1939...Great Falls began in 1891...Havre and Helena began 
 in 1880...and Lewistown began in 1896. West Yellowstone records began
 in 1905...winds began in 2010. Bozeman MSUs records began in 1868
 for precipitation and 1892 for temperature and snowfall. The normal
 period for all elements is 1981 to 2010.
 
 These data are preliminary and have not undergone final QC by NCEI.
 Therefore these data are subject to revision. Final and certified
 climate data can be accessed at the National Centers for          
 Environmental Information at www.ncei.noaa.gov