Weather Records on 21 May 1917

76 weather records were set or tied worldwide on 21 May 1917. Highest significance: Milwaukee Wb City, US.

Key Facts for 21 May 1917

On 21 May 1917, 76 weather records were set or tied at long-record stations worldwide.
6 were record highs and 39 were record lows, counting maximum and minimum temperature.
By timescale, 0 were all-time records, 2 monthly and 74 daily.
Milwaukee Wb City set a daily record precipitation of 35.1 mm (1.4 in) on 21 May 1917.
Across 156 earlier years (1793 to 2026) the same calendar date averaged 463 records.

Record Map

76 stations

76 station records on 21 May 1917 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 21 May 1917: highest significance records shown on the map
Station	Country	Type	Value	Significance
Milwaukee Wb City	United States	Record daily precipitation	35.1 mm (1.4 in)	27 of 100 (Routine)
Uccle	Belgium	Record high minimum temperature	15.1 C (59.2 F)	25 of 100 (Routine)
Uppsala_Aut	Sweden	Record low minimum temperature	-6.0 C (21.2 F)	25 of 100 (Routine)
Kristianstad	Sweden	Record low maximum temperature	7.0 C (44.6 F)	22 of 100 (Routine)
Sandvig	Denmark	Record low minimum temperature	2.0 C (35.6 F)	21 of 100 (Routine)
Beeac (Eurack)	Australia	Record daily precipitation	21.6 mm (0.9 in)	20 of 100 (Routine)
Bird Rocks	Canada	Record daily precipitation	17.8 mm (0.7 in)	20 of 100 (Routine)
Niznij Novgorod	Russia	Record daily precipitation	24.1 mm (0.9 in)	20 of 100 (Routine)
Cap Madeleine	Canada	Record daily precipitation	22.9 mm (0.9 in)	20 of 100 (Routine)
Naracoorte	Australia	Record daily precipitation	19.1 mm (0.8 in)	20 of 100 (Routine)
Lyndoch (Pewsey Vale)	Australia	Record daily precipitation	22.9 mm (0.9 in)	19 of 100 (Routine)
Linkoeping-Malmslaett	Sweden	Record low minimum temperature	-2.5 C (27.5 F)	19 of 100 (Routine)
Lucindale Post Office	Australia	Record daily precipitation	12.2 mm (0.5 in)	18 of 100 (Routine)
Newlyn Reservoir	Australia	Record daily precipitation	31.5 mm (1.2 in)	18 of 100 (Routine)
Vasteras-Hasslo	Sweden	Record low minimum temperature	-4.5 C (23.9 F)	18 of 100 (Routine)
Tumby Bay (Warratta Vale)	Australia	Record daily precipitation	5.8 mm (0.23 in)	17 of 100 (Routine)
Mount Torrens	Australia	Record daily precipitation	28.2 mm (1.1 in)	17 of 100 (Routine)
Greenville Dwtn AP	United States	Record high maximum temperature	34.4 C (93.9 F)	17 of 100 (Routine)
Lobethal	Australia	Record daily precipitation	29.5 mm (1.2 in)	16 of 100 (Routine)
Galway	Ireland	Record daily precipitation	26.0 mm (1.0 in)	16 of 100 (Routine)
Kiev	Ukraine	Record low minimum temperature	0.0 C (32.0 F)	16 of 100 (Routine)
Gumeracha	Australia	Record daily precipitation	23.9 mm (0.9 in)	15 of 100 (Routine)
Charlottetown	Canada	Record low maximum temperature	6.7 C (44.1 F)	15 of 100 (Routine)
Stellenbosch (Tnk)	South Africa	Record daily precipitation	17.8 mm (0.7 in)	15 of 100 (Routine)
Vastervik	Sweden	Record low minimum temperature	0.0 C (32.0 F)	15 of 100 (Routine)
Cap Madeleine	Canada	Record daily snowfall	1.3 cm (0.5 in)	14 of 100 (Routine)
Pitea	Sweden	Record low minimum temperature	-4.0 C (24.8 F)	14 of 100 (Routine)
Parnu	Estonia	Record low minimum temperature	-2.3 C (27.9 F)	13 of 100 (Routine)
St. Petersburg	Russia	Record low minimum temperature	-2.0 C (28.4 F)	13 of 100 (Routine)
Visby_Flygplats	Sweden	Record low minimum temperature	-2.0 C (28.4 F)	13 of 100 (Routine)
Halmstad	Sweden	Record low minimum temperature	-1.0 C (30.2 F)	13 of 100 (Routine)
Lyndoch	Australia	Record daily precipitation	13.0 mm (0.5 in)	12 of 100 (Routine)
Nairne	Australia	Record daily precipitation	22.9 mm (0.9 in)	12 of 100 (Routine)
Atyrau	Kazakhstan	Record daily precipitation	4.6 mm (0.18 in)	12 of 100 (Routine)
Arhangelsk	Russia	Record low minimum temperature	-5.5 C (22.1 F)	12 of 100 (Routine)
Kristianstad	Sweden	Record low minimum temperature	0.5 C (32.9 F)	12 of 100 (Routine)
Orebro	Sweden	Record low minimum temperature	-2.0 C (28.4 F)	12 of 100 (Routine)
Madison Wb City	United States	Record daily precipitation	23.4 mm (0.9 in)	12 of 100 (Routine)
Cape Jervis Lighthouse	Australia	Record daily precipitation	7.1 mm (0.28 in)	11 of 100 (Routine)
Daylesford	Australia	Record daily precipitation	21.6 mm (0.9 in)	11 of 100 (Routine)
Haparanda	Sweden	Record low minimum temperature	-5.0 C (23.0 F)	11 of 100 (Routine)
Karlshamn	Sweden	Record low maximum temperature	7.5 C (45.5 F)	11 of 100 (Routine)
Karesuando	Sweden	Record low minimum temperature	-10.0 C (14.0 F)	11 of 100 (Routine)
Madison Wb City	United States	Record low maximum temperature	7.8 C (46.0 F)	11 of 100 (Routine)
Collingrove	Australia	Record daily precipitation	17.8 mm (0.7 in)	10 of 100 (Routine)
Macarthur (Glenhuntly)	Australia	Record daily precipitation	20.3 mm (0.8 in)	10 of 100 (Routine)
Hvar	Croatia	Record high minimum temperature	19.6 C (67.3 F)	10 of 100 (Routine)
Harnosand	Sweden	Record low minimum temperature	-3.0 C (26.6 F)	10 of 100 (Routine)
Vanersborg	Sweden	Record low minimum temperature	0.0 C (32.0 F)	10 of 100 (Routine)
Bjuraker	Sweden	Record low minimum temperature	-5.5 C (22.1 F)	10 of 100 (Routine)
Wilmington Wb City	United States	Record high maximum temperature	32.8 C (91.0 F)	10 of 100 (Routine)
Green Bay	United States	Record low maximum temperature	7.2 C (45.0 F)	10 of 100 (Routine)
Lincoln UNIV Pwr Plt	United States	Record daily precipitation	36.3 mm (1.4 in)	10 of 100 (Routine)
Angaston	Australia	Record daily precipitation	9.9 mm (0.39 in)	9 of 100 (Routine)
Jamieson	Australia	Record daily precipitation	35.3 mm (1.4 in)	9 of 100 (Routine)
Macclesfield	Australia	Record daily precipitation	13.2 mm (0.5 in)	8 of 100 (Routine)
Brisbane Regional Office	Australia	Record low minimum temperature	5.8 C (42.4 F)	8 of 100 (Routine)
Gunnedah Pool	Australia	Record low maximum temperature	12.8 C (55.0 F)	8 of 100 (Routine)
Karlsruhe	Germany	Record high minimum temperature	16.9 C (62.4 F)	8 of 100 (Routine)
Woodside	Australia	Record daily precipitation	15.7 mm (0.6 in)	7 of 100 (Routine)

Counts by Type and Timescale

76 records

Records set or tied on 21 May 1917 by type: Highest daily maximum 2, Lowest daily maximum 10, Highest daily minimum 4, Lowest daily minimum 29, Heaviest daily rainfall 30, Heaviest daily snowfall 1.

Records on 21 May 1917 by type
Record type	Records
Highest daily maximum	2
Lowest daily maximum	10
Highest daily minimum	4
Lowest daily minimum	29
Heaviest daily rainfall	30
Heaviest daily snowfall	1
Deepest snow cover	0

Records on 21 May 1917 by timescale: all-time 0, monthly 2, daily 74.

How Much Records Were Beaten By

64 broken records

Margins by which the 64 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 15.3. Ties are not counted.

Top 20 by Significance

21 May 1917

Top 20 records on 21 May 1917 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
21 May 1917	Milwaukee Wb City, US	daily rain	35.1 mm (1.4 in)	15.3 mm (0.6 in)	22 years	27 of 100 (Routine)
21 May 1917	Uccle, BE	daily high min	15.1 C (59.2 F)	0.3 C (0.5 F)	59 years	25 of 100 (Routine)
21 May 1917	Uppsala_Aut, SE	daily low min	-6.0 C (21.2 F)	1.3 C (2.3 F)	50 years	25 of 100 (Routine)
21 May 1917	Kristianstad, SE	daily low max	7.0 C (44.6 F)	4.5 C (8.1 F)	29 years	22 of 100 (Routine)
21 May 1917	Sandvig, DK	daily low min	2.0 C (35.6 F)	1.5 C (2.7 F)	39 years	21 of 100 (Routine)
21 May 1917	Beeac (Eurack), AU	daily rain	21.6 mm (0.9 in)	13.2 mm (0.5 in)	31 years	20 of 100 (Routine)
21 May 1917	Bird Rocks, CA	daily rain	17.8 mm (0.7 in)	12.2 mm (0.5 in)	14 years	20 of 100 (Routine)
21 May 1917	Niznij Novgorod, RU	daily rain	24.1 mm (0.9 in)	10.9 mm (0.4 in)	4 years	20 of 100 (Routine)
21 May 1917	Cap Madeleine, CA	daily rain	22.9 mm (0.9 in)	8.9 mm (0.35 in)	16 years	20 of 100 (Routine)
21 May 1917	Naracoorte, AU	daily rain	19.1 mm (0.8 in)	4.1 mm (0.16 in)	27 years	20 of 100 (Routine)
21 May 1917	Lyndoch (Pewsey Vale), AU	daily rain	22.9 mm (0.9 in)	6.1 mm (0.24 in)	27 years	19 of 100 (Routine)
21 May 1917	Linkoeping-Malmslaett, SE	daily low min	-2.5 C (27.5 F)	3.5 C (6.3 F)	23 years	19 of 100 (Routine)
21 May 1917	Lucindale Post Office, AU	daily rain	12.2 mm (0.5 in)	4.8 mm (0.19 in)	27 years	18 of 100 (Routine)
21 May 1917	Newlyn Reservoir, AU	daily rain	31.5 mm (1.2 in)	5.8 mm (0.23 in)	27 years	18 of 100 (Routine)
21 May 1917	Vasteras-Hasslo, SE	daily low min	-4.5 C (23.9 F)	3.5 C (6.3 F)	22 years	18 of 100 (Routine)
21 May 1917	Tumby Bay (Warratta Vale), AU	daily rain	5.8 mm (0.23 in)	3.3 mm (0.13 in)	26 years	17 of 100 (Routine)
21 May 1917	Mount Torrens, AU	daily rain	28.2 mm (1.1 in)	4.8 mm (0.19 in)	27 years	17 of 100 (Routine)
21 May 1917	Greenville Dwtn AP, US	daily high max	34.4 C (93.9 F)	2.2 C (4.0 F)	32 years	17 of 100 (Routine)
21 May 1917	Lobethal, AU	daily rain	29.5 mm (1.2 in)	4.9 mm (0.19 in)	27 years	16 of 100 (Routine)
21 May 1917	Galway, IE	daily rain	26.0 mm (1.0 in)	5.6 mm (0.22 in)	2 years	16 of 100 (Routine)

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 1917

Records set or tied on this calendar date in each year from 1793 to 1917. 1917 had 76 records.

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

Records on 05-21 in each year
Year	Records
1793	1
1795	1
1811	1
1837	2
1842	1
1847	2
1854	1
1857	1
1858	1
1865	1
1866	1
1870	2
1875	1
1876	1
1880	2
1882	1
1885	1
1886	2
1887	3
1889	5
1890	3
1891	6
1892	1
1893	1
1894	4
1895	4
1896	5
1897	2
1898	1
1899	5
1900	1
1901	3
1902	4
1903	26
1904	8
1905	7
1906	12
1907	36
1908	13
1909	13
1910	14
1911	87
1912	24
1913	13
1914	26
1915	24
1916	13
1917	76
1918	51
1919	170
1920	39
1921	158
1922	39
1923	125
1924	148
1925	250
1926	221
1927	207
1928	173
1929	247
1930	133
1931	488
1932	343
1933	290
1934	590
1935	190
1936	328
1937	227
1938	348
1939	355
1940	456
1941	525
1942	482
1943	463
1944	310
1945	515
1946	324
1947	485
1948	312
1949	593
1950	403
1951	271
1952	385
1953	501
1954	961
1955	507
1956	409
1957	709
1958	511
1959	684
1960	615
1961	306
1962	553
1963	598
1964	788
1965	238
1966	296
1967	1,022
1968	549
1969	832
1970	449
1971	536
1972	557
1973	493
1974	847
1975	1,160
1976	393
1977	756
1978	575
1979	787
1980	857
1981	1,550
1982	599
1983	1,106
1984	950
1985	610
1986	908
1987	1,242
1988	819
1989	671
1990	947
1991	1,065
1992	1,143
1993	1,197
1994	656
1995	749
1996	1,461
1997	953
1998	1,200
1999	544
2000	897
2001	1,187
2002	2,048
2003	807
2004	898
2005	1,020
2006	810
2007	894
2008	740
2009	1,315
2010	962
2011	959
2012	848
2013	884
2014	522
2015	956
2016	567
2017	780
2018	525
2019	1,668
2020	707
2021	1,131
2022	1,512
2023	794
2024	751
2025	776
2026	356

Download the Data

Data for records on 1917-05-21: 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 2026-10-12. Last revised 12 October 2026 (2026-10-12).

Margin	Records
0 to 2	32
2 to 4	13
4 to 6	11
6 to 8	1
8 to 10	2
10 to 12	1
12 to 14	3
14 to 16	1