User:KingLucarius/sandbox/Snowfall in Boulder, Colorado

Climatology

Winter snowfall is a significant contributor to the annual precipitation of large portions of the overall dry and semi-arid climate that dominates large portions of Colorado. Boulder, Colorado is one such city, normally receiving around 92.8 inches (2367.3 mm) of snowfall throughout the autumn, winter and spring months of the year. Despite snowfall typically peaking in the early to mid-spring months of the year, specifically March; instances of measurable snowfall have been observed historically in every month of the calendar year except for July and August. Due to snowfall being practical for most of the year across higher elevations in the United States, no seasonal bounds for it are specified by the National Weather Service (NWS). However, totals listed below are reset to the following year on July 1, similarly to the seasonal bounds used by agencies for designating tropical cyclones in the Southern Hemisphere.

History & methodology

Beginning in 1893, the National Weather Service and their Denver-Boulder (BOU) office began keeping archives of snowfall data in Colorado. This practice has continued into the present day with such archives available for several different locations across the state. For the purposes of this article, all listed data and information is be based upon the archives for Boulder, Colorado. Below are a set of tables depicting historical snowfall in the city; separated by season, their classifications relative to the 1991-2020 mean, and the criteria for said classifications.

Classification criteria
Category	% of 1991-2020 normal	Snowfall total
Normal	-	~ 92.8"
Extremely active	Above 150%	Above 139.2"
Above normal	Above 114%	Above 105.8"
Near normal	85-114%	78.9-105.8"
Below normal	Below 85%	Below 78.9"

Historical snowfall by season

50

100

150

200

1951

1961

1971

1981

1991

2001

2011

2021

Extremely active

Above normal

Near normal

Below normal

Historical snowfall by season
Boulder, Colorado
Season	Snow	T	M	Avg.	Classification
2023-24	22.1	5	4	4.42	Current season
2022-23	80.9	31	23	2.61	Near normal
2021-22	88.7	26	20	3.412	Near normal
2020-21	103.3	35	24	2.951	Near normal
2019-20	152.0	25	21	6.08	Extremely active
2018-19	95.1	32	28	2.972	Near normal
2017-18	62.4	28	24	2.229	Below normal
2016-17	71.5	19	17	3.763	Below normal
2015-16	109.7	23	19	4.77	Above normal
2014-15	117.1	30	23	3.903	Above normal
2013-14	89.8	33	24	2.7	Near normal
2012-13	124.5	27	23	4.611	Above normal
2011-12	94.7	27	18	3.507	Near normal
2010-11	47.3	30	20	1.577	Below normal
2009-10	134.5	37	32	3.635	Above normal
2008-09	81.1	30	19	2.703	Near normal
2007-08	82.9	38	28	2.182	Near normal
2006-07	122.2	32	27	3.819	Above normal
2005-06	51.4	30	17	1.713	Below normal
2004-05	76.7	26	20	2.95	Below normal
2003-04	70.6	26	22	2.715	Below normal
2002-03	99.0	31	23	3.194	Near normal
2001-02	63.4	33	23	1.921	Below normal
2000-01	83.8	34	27	2.465	Near normal
1999-00	71.9	25	17	2.876	Below normal
1998-99	81.4	27	17	3.015	Near normal
1997-98	132.6	32	24	4.144	Above normal
1996-97	129.4	39	30	3.318	Above normal
1995-96	93.2				Near normal
1994-95	104.0				Near normal
1993-94	112.5				Above normal
1992-93	95.3				Near normal
1991-92	73.3				Below normal
1990-91	76.6				Below normal
1989-90	91.8				Near normal
1988-89	92.5				Near normal
1987-88	94.8				Near normal
1986-87	124.7				Above normal
1985-86	92.1				Near normal
1984-85	72.2				Below normal
1983-84	88.5				Near normal
1982-83	70.8				Below normal
1981-82	20.8				Below normal
1980-81	40.0				Below normal
1979-80	115.4				Above normal
1978-79	67.7				Below normal
1977-78	76.0				Below normal
1976-77	39.8				Below normal
1975-76	58.9				Below normal
1974-75	84.0				Near normal
1973-74	83.8				Near normal
1972-73	128.3				Above normal
1971-72	76.3				Below normal
1970-71	67.2				Below normal
1969-70	134.5				Above normal
1968-69	46.4				Below normal
1967-68	97.7				Near normal
1966-67	56.4				Below normal
1965-66	63.5				Below normal
1964-65	98.9				Near normal
1963-64	74.0				Below normal
1962-63	59.5				Below Normal
1961-62	81.5				Near normal
1960-61	74.5				Below normal
1959-60	90.8				Near normal
1958-59	101.5				Near normal
1957-58	70.4				Below normal
1956-57	103.2				Near normal
1955-56	84.7				Near normal
1954-55	72.0				Below normal
1953-54	63.6				Below normal
1952-53	89.0				Near normal
1951-52	85.3				Near normal
1950-51	96.9				Near normal
1949-50	54.7				Below normal
1948-49	91.4				Near normal
1947-48	109.7				Above normal
1946-47	137.0				Above normal
1945-46	52.8				Below normal
1944-45	87.3				Near normal
1943-44	105.3				Near normal
1942-43	70.0				Below normal
1941-42	76.5				Below normal
1940-41	72.5				Below normal
1939-40	73.5				Below normal
1938-39	87.7				Near normal
1937-38	76.7				Below normal
1936-37	64.9				Below normal
1936-36	60.9				Below normal
1934-35	42.9				Below normal
1933-34	57.1				Below normal
1932-33	75.2				Below normal
1931-32	52.6				Below normal
1930-31	98.9				Near normal
1929-30	78.1				Below normal
1928-29	65.2				Below normal
1927-28	63.5				Below normal
1926-27	50.0				Below normal
1925-26	75.8				Below normal
1924-25	21.5				Below normal
1923-24	73.3				Below normal
1922-23	70.7				Below normal
1921-22	43.1				Below normal
1920-21	62.0				Below normal
1919-20	90.3				Near normal
1918-19	52.9				Below normal
1917-18	34.3				Below normal
1916-17	103.3				Near normal
1915-16	66.7				Below normal
1914-15	64.2				Below normal
1913-14	104.9				Near normal
1912-13	62.9				Below normal
1911-12	68.3				Below normal
1910-11	55.6				Below normal
1909-10	80.5				Near normal
1908-09	142.9				Extremely active
1907-08	38.1				Below normal
1906-07	96.2				Near normal
1905-06	50.7				Below normal
1904-05	68.5				Below normal
1903-04	38.2				Below normal
1902-03	78.5				Below normal
1901-02	45.2				Below normal
1900-01	70.5				Below normal
1899-00	60.9				Below normal
1898-99	114.7				Above normal
1897-98	63.1				Below normal
1896-97	≥ 41.0				Below normal
1895-96	N/A				Missing
1894-95	≥ 42.5				Below normal
1893-94	≥ 23.0				Below normal

Snowiest single storms

List of the snowiest winter storms (> 18")
Storm	Season	Snowfall	Month
Xylia	2020-21	21.3	March
Ruth	2019-20	18.7	April
Dorothy	2019-20	22.5	November
Yogi	2012-13	20.5	April
Nixi	2011-12	22.7	February
Six	2009-10	23.0	October
Twenty-Five	2008-09	20.4	March
Nine	2006-07	26.0	December
Twenty-Four	2002-03	22.5	March
Twenty-Four	1997-98	20.8	March
Two	1997-98	29.9	October
Thirty-Eight	1996-97	19.8	April