Weather Records on 21 December 2017

459 weather records were set or tied worldwide on 21 December 2017. Highest significance: Riggins, US.

Key Facts for 21 December 2017

On 21 December 2017, 459 weather records were set or tied at long-record stations worldwide.
235 were record highs and 52 were record lows, counting maximum and minimum temperature.
By timescale, 2 were all-time records, 16 monthly and 441 daily.
Riggins set a monthly record daily precipitation of 50.8 mm (2.0 in) on 21 December 2017.
Across 158 earlier years (1793 to 2025) the same calendar date averaged 490 records.

Record Map

459 stations

459 station records on 21 December 2017 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 21 December 2017: highest significance records shown on the map
Station	Country	Type	Value	Significance
Riggins	United States	Record daily precipitation	50.8 mm (2.0 in)	78 of 100 (Major)
Moab	United States	Record daily snowfall	22.9 cm (9.0 in)	77 of 100 (Major)
Cloquet	United States	Record daily precipitation	27.9 mm (1.1 in)	69 of 100 (Major)
Waikapu 390	United States	Record daily precipitation	212.1 mm (8.4 in)	61 of 100 (Major)
Siwa	Egypt	Record high minimum temperature	17.9 C (64.2 F)	57 of 100 (Notable)
Opihihale #2 24.1	United States	Record daily precipitation	80.0 mm (3.1 in)	56 of 100 (Notable)
Jixi	China	Record daily precipitation	30.0 mm (1.2 in)	53 of 100 (Notable)
Waiehu Camp 484	United States	Record daily precipitation	242.6 mm (9.6 in)	51 of 100 (Notable)
Rosalie Plains	Australia	Record daily precipitation	91.0 mm (3.6 in)	48 of 100 (Notable)
Kapalua-W Maui AP 462.4	United States	Record daily precipitation	90.2 mm (3.6 in)	48 of 100 (Notable)
Port-Aux-Francais (Iles Kergu	France	Record daily precipitation	26.9 mm (1.1 in)	47 of 100 (Notable)
Howard 2SE	United States	Record high minimum temperature	7.2 C (45.0 F)	47 of 100 (Notable)
Holter Dam	United States	Record snow depth	20.3 cm (8.0 in)	46 of 100 (Notable)
Jeffrey City	United States	Record daily snowfall	12.7 cm (5.0 in)	46 of 100 (Notable)
Waterville 2	United States	Record daily precipitation	40.6 mm (1.6 in)	45 of 100 (Notable)
Moab	United States	Record snow depth	15.2 cm (6.0 in)	45 of 100 (Notable)
Waihee Vly 482	United States	Record daily precipitation	176.8 mm (7.0 in)	45 of 100 (Notable)
Romsey (Shire Office)	Australia	Record daily precipitation	35.2 mm (1.4 in)	43 of 100 (Notable)
Sumter	United States	Record daily precipitation	36.3 mm (1.4 in)	43 of 100 (Notable)
McAlester Rgnl AP	United States	Record high maximum temperature	23.9 C (75.0 F)	43 of 100 (Notable)
Guyra Hospital	Australia	Record daily precipitation	54.0 mm (2.1 in)	42 of 100 (Notable)
Santo Domingo	Dominican Republic	Record high maximum temperature	34.0 C (93.2 F)	42 of 100 (Notable)
Curtis	United States	Record high minimum temperature	0.6 C (33.1 F)	41 of 100 (Notable)
Milolii 2.34	United States	Record daily precipitation	78.7 mm (3.1 in)	41 of 100 (Notable)
Mersa Matruh	Egypt	Record high minimum temperature	17.0 C (62.6 F)	39 of 100 (Notable)
Inverness 3 SE	United States	Record high minimum temperature	18.3 C (64.9 F)	39 of 100 (Notable)
Chinook	United States	Record daily snowfall	7.6 cm (3.0 in)	39 of 100 (Notable)
Kaneohe 838.1	United States	Record daily precipitation	29.0 mm (1.1 in)	39 of 100 (Notable)
Wick	United Kingdom	Record high maximum temperature	13.0 C (55.4 F)	38 of 100 (Notable)
Yates Ctr	United States	Record high minimum temperature	6.1 C (43.0 F)	38 of 100 (Notable)
Mahnomen	United States	Record daily snowfall	15.2 cm (6.0 in)	38 of 100 (Notable)
Segou	Mali	Record low maximum temperature	23.5 C (74.3 F)	37 of 100 (Notable)
Puukolii 457.1	United States	Record daily precipitation	64.0 mm (2.5 in)	37 of 100 (Notable)
Koutiala	Mali	Record low maximum temperature	24.2 C (75.6 F)	36 of 100 (Notable)
Norman 3SSE	United States	Record high minimum temperature	7.8 C (46.0 F)	36 of 100 (Notable)
Lamar 7N	United States	Record high minimum temperature	6.1 C (43.0 F)	35 of 100 (Notable)
Malta 35 S	United States	Record daily snowfall	16.5 cm (6.5 in)	35 of 100 (Notable)
Chugwater	United States	Record high maximum temperature	16.7 C (62.1 F)	35 of 100 (Notable)
Gravette	United States	Record high maximum temperature	20.6 C (69.1 F)	34 of 100 (Routine)
Lakeside	United States	Record high minimum temperature	8.9 C (48.0 F)	34 of 100 (Routine)
Agate 3 E	United States	Record daily snowfall	10.7 cm (4.2 in)	34 of 100 (Routine)
Claremore 2 ENE	United States	Record high minimum temperature	10.0 C (50.0 F)	34 of 100 (Routine)
King Hussein	Jordan	Record high minimum temperature	11.4 C (52.5 F)	33 of 100 (Routine)
Harrison	United States	Record high minimum temperature	10.0 C (50.0 F)	33 of 100 (Routine)
Wainwright AP	United States	Record high minimum temperature	-6.6 C (20.1 F)	33 of 100 (Routine)
Kushiro	Japan	Record daily precipitation	80.0 mm (3.1 in)	32 of 100 (Routine)
Rome	United States	Record daily precipitation	51.3 mm (2.0 in)	32 of 100 (Routine)
New London Lock #22	United States	Record daily snowfall	15.2 cm (6.0 in)	32 of 100 (Routine)
Antreville	United States	Record daily precipitation	33.3 mm (1.3 in)	32 of 100 (Routine)
Lockhart	United States	Record daily precipitation	41.9 mm (1.6 in)	32 of 100 (Routine)
Arches Np Hqs	United States	Record daily snowfall	14.0 cm (5.5 in)	32 of 100 (Routine)
Canyonlands-the Neck	United States	Record daily snowfall	15.2 cm (6.0 in)	32 of 100 (Routine)
Kotzebue AP	United States	Record high maximum temperature	1.7 C (35.1 F)	32 of 100 (Routine)
Bishopville 1.4 ENE	United States	Record daily precipitation	26.7 mm (1.1 in)	31 of 100 (Routine)
Flaming Gorge	United States	Record daily snowfall	12.7 cm (5.0 in)	31 of 100 (Routine)
Circle Hot Springs	United States	Record high minimum temperature	-3.3 C (26.1 F)	31 of 100 (Routine)
Keaau 92	United States	Record daily precipitation	145.3 mm (5.7 in)	31 of 100 (Routine)
Ostrov Vrangelja	Russia	Record high minimum temperature	-9.1 C (15.6 F)	30 of 100 (Routine)
East London	South Africa	Record daily precipitation	36.1 mm (1.4 in)	30 of 100 (Routine)
Van	Turkey	Record high maximum temperature	12.7 C (54.9 F)	30 of 100 (Routine)

Counts by Type and Timescale

459 records

Records set or tied on 21 December 2017 by type: Highest daily maximum 107, Lowest daily maximum 30, Highest daily minimum 128, Lowest daily minimum 22, Heaviest daily rainfall 115, Heaviest daily snowfall 41, Deepest snow cover 16.

Records on 21 December 2017 by type
Record type	Records
Highest daily maximum	107
Lowest daily maximum	30
Highest daily minimum	128
Lowest daily minimum	22
Heaviest daily rainfall	115
Heaviest daily snowfall	41
Deepest snow cover	16

Records on 21 December 2017 by timescale: all-time 2, monthly 16, daily 441.

How Much Records Were Beaten By

373 broken records

Margins by which the 373 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 178.0. Ties are not counted.

Top 20 by Significance

21 December 2017

Top 20 records on 21 December 2017 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
21 December 2017	Riggins, US	monthly rain	50.8 mm (2.0 in)	12.7 mm (0.5 in)	112 years	78 of 100 (Major)
21 December 2017	Moab, US	daily snowfall	22.9 cm (9.0 in)	17.8 cm (7.0 in)	107 years	77 of 100 (Major)
21 December 2017	Cloquet, US	daily rain	27.9 mm (1.1 in)	19.5 mm (0.8 in)	66 years	69 of 100 (Major)
21 December 2017	Waikapu 390, US	monthly rain	212.1 mm (8.4 in)	33.0 mm (1.3 in)	92 years	61 of 100 (Major)
21 December 2017	Siwa, EG	daily high min	17.9 C (64.2 F)	5.9 C (10.6 F)	96 years	57 of 100 (Notable)
21 December 2017	Opihihale #2 24.1, US	daily rain	80.0 mm (3.1 in)	52.8 mm (2.1 in)	43 years	56 of 100 (Notable)
21 December 2017	Jixi, CN	daily rain	30.0 mm (1.2 in)	25.8 mm (1.0 in)	24 years	53 of 100 (Notable)
21 December 2017	Waiehu Camp 484, US	all-time rain	242.6 mm (9.6 in)	12.2 mm (0.5 in)	62 years	51 of 100 (Notable)
21 December 2017	Rosalie Plains, AU	monthly rain	91.0 mm (3.6 in)	25.5 mm (1.0 in)	47 years	48 of 100 (Notable)
21 December 2017	Kapalua-W Maui AP 462.4, US	daily rain	90.2 mm (3.6 in)	73.9 mm (2.9 in)	16 years	48 of 100 (Notable)
21 December 2017	Port-Aux-Francais (Iles Kergu, FR	daily rain	26.9 mm (1.1 in)	19.8 mm (0.8 in)	28 years	47 of 100 (Notable)
21 December 2017	Howard 2SE, US	daily high min	7.2 C (45.0 F)	5.0 C (9.0 F)	96 years	47 of 100 (Notable)
21 December 2017	Holter Dam, US	daily snow depth	20.3 cm (8.0 in)	7.6 cm (3.0 in)	78 years	46 of 100 (Notable)
21 December 2017	Jeffrey City, US	daily snowfall	12.7 cm (5.0 in)	12.7 cm (5.0 in)	39 years	46 of 100 (Notable)
21 December 2017	Waterville 2, US	daily rain	40.6 mm (1.6 in)	23.8 mm (0.9 in)	39 years	45 of 100 (Notable)
21 December 2017	Moab, US	daily snow depth	15.2 cm (6.0 in)	2.5 cm (1.0 in)	119 years	45 of 100 (Notable)
21 December 2017	Waihee Vly 482, US	daily rain	176.8 mm (7.0 in)	39.6 mm (1.6 in)	62 years	45 of 100 (Notable)
21 December 2017	Romsey (Shire Office), AU	daily rain	35.2 mm (1.4 in)	32.4 mm (1.3 in)	22 years	43 of 100 (Notable)
21 December 2017	Sumter, US	daily rain	36.3 mm (1.4 in)	4.0 mm (0.16 in)	112 years	43 of 100 (Notable)
21 December 2017	McAlester Rgnl AP, US	daily high max	23.9 C (75.0 F)	2.2 C (4.0 F)	114 years	43 of 100 (Notable)

Significance is a score from 0 to 100 combining margin, the age of the old record and the length of the station's record. How it is computed.

The Same Date in Other Years

1793 to 2017

Records set or tied on this calendar date in each year from 1793 to 2017. 2017 had 459 records.

Counts for years before the ledger starts come from the same station rules.

Records on 12-21 in each year
Year	Records
1793	1
1794	1
1799	1
1801	2
1808	3
1825	1
1828	1
1839	1
1846	1
1850	1
1855	7
1859	1
1860	1
1868	1
1870	1
1871	2
1874	2
1875	3
1876	1
1877	1
1878	1
1879	1
1880	1
1884	1
1886	3
1889	1
1890	4
1893	4
1894	1
1895	5
1896	3
1897	3
1898	1
1900	8
1901	15
1902	5
1903	25
1904	3
1905	15
1906	15
1907	17
1908	19
1909	20
1910	29
1911	36
1912	23
1913	11
1914	107
1915	43
1916	40
1917	18
1918	41
1919	57
1920	30
1921	104
1922	34
1923	323
1924	377
1925	120
1926	178
1927	147
1928	70
1929	156
1930	66
1931	556
1932	150
1933	581
1934	230
1935	398
1936	323
1937	189
1938	145
1939	140
1940	622
1941	651
1942	968
1943	148
1944	762
1945	396
1946	495
1947	700
1948	297
1949	1,281
1950	504
1951	1,061
1952	197
1953	256
1954	444
1955	888
1956	672
1957	846
1958	516
1959	272
1960	585
1961	254
1962	563
1963	1,137
1964	613
1965	247
1966	400
1967	1,923
1968	818
1969	828
1970	547
1971	680
1972	651
1973	1,292
1974	374
1975	548
1976	446
1977	470
1978	517
1979	558
1980	726
1981	1,476
1982	702
1983	3,324
1984	1,012
1985	979
1986	404
1987	775
1988	717
1989	3,203
1990	2,701
1991	1,125
1992	751
1993	967
1994	793
1995	878
1996	1,114
1997	810
1998	1,142
1999	851
2000	944
2001	650
2002	579
2003	1,103
2004	675
2005	606
2006	1,443
2007	946
2008	1,062
2009	1,097
2010	2,039
2011	653
2012	759
2013	1,029
2014	878
2015	1,173
2016	543
2017	459
2018	742
2019	755
2020	965
2021	323
2022	528
2023	1,170
2024	778
2025	1,100

Download the Data

Data for records on 2017-12-21: CSV or JSON. Field meanings are on the data page.

Sources: Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Made with Natural Earth. Public domain map data. Borders are Natural Earth's de facto depiction. Data as of 2026-10-14 (14 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-13. Last revised 13 October 2026 (2026-10-13).

Margin	Records
0 to 25	326
25 to 50	26
50 to 75	12
75 to 100	5
100 to 125	2
125 to 150	1
150 to 175	0
175 to 200	1