Weather Records on 21 August 1917

101 weather records were set or tied worldwide on 21 August 1917. Highest significance: Jamestown, AU.

Key Facts for 21 August 1917

On 21 August 1917, 101 weather records were set or tied at long-record stations worldwide.
2 were record highs and 9 were record lows, counting maximum and minimum temperature.
By timescale, 0 were all-time records, 2 monthly and 99 daily.
Jamestown set a daily record precipitation of 34.3 mm (1.4 in) on 21 August 1917.
Across 165 earlier years (1800 to 2026) the same calendar date averaged 452 records.

Record Map

101 stations

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

Weather records on 21 August 1917: highest significance records shown on the map
Station	Country	Type	Value	Significance
Jamestown	Australia	Record daily precipitation	34.3 mm (1.4 in)	44 of 100 (Notable)
Hingham (1)	United States	Record daily precipitation	104.9 mm (4.1 in)	42 of 100 (Notable)
Bridgewater	Australia	Record daily precipitation	45.7 mm (1.8 in)	40 of 100 (Notable)
Gorlitz	Germany	Record daily precipitation	43.6 mm (1.7 in)	37 of 100 (Notable)
Mundoora	Australia	Record daily precipitation	29.2 mm (1.1 in)	33 of 100 (Routine)
Port Victoria	Australia	Record daily precipitation	12.7 mm (0.5 in)	20 of 100 (Routine)
Edithburgh Post Office	Australia	Record daily precipitation	13.5 mm (0.5 in)	20 of 100 (Routine)
Adelaide (Thorndon Park)	Australia	Record daily precipitation	15.0 mm (0.6 in)	20 of 100 (Routine)
Lobethal	Australia	Record daily precipitation	24.1 mm (0.9 in)	20 of 100 (Routine)
North Adelaide	Australia	Record daily precipitation	18.3 mm (0.7 in)	20 of 100 (Routine)
Balaklava	Australia	Record daily precipitation	15.5 mm (0.6 in)	20 of 100 (Routine)
Plauen	Germany	Record daily precipitation	19.1 mm (0.8 in)	20 of 100 (Routine)
Warooka	Australia	Record daily precipitation	9.7 mm (0.38 in)	20 of 100 (Routine)
Mitcham Post Office	Australia	Record daily precipitation	13.2 mm (0.5 in)	20 of 100 (Routine)
Adelaide (Pooraka)	Australia	Record daily precipitation	12.7 mm (0.5 in)	20 of 100 (Routine)
Dingo Vale	Australia	Record daily precipitation	29.2 mm (1.1 in)	20 of 100 (Routine)
Bendigo Prison	Australia	Record daily precipitation	10.9 mm (0.4 in)	20 of 100 (Routine)
Kanmantoo	Australia	Record daily precipitation	14.0 mm (0.6 in)	19 of 100 (Routine)
Mount Barker	Australia	Record daily precipitation	25.7 mm (1.0 in)	19 of 100 (Routine)
Truro	Australia	Record daily precipitation	22.1 mm (0.9 in)	19 of 100 (Routine)
Buangor 1	Australia	Record daily precipitation	18.3 mm (0.7 in)	19 of 100 (Routine)
Munchen-Nymphenburg	Germany	Record daily precipitation	25.4 mm (1.0 in)	19 of 100 (Routine)
Mount Torrens	Australia	Record daily precipitation	24.1 mm (0.9 in)	18 of 100 (Routine)
Canary Island	Australia	Record daily precipitation	10.2 mm (0.4 in)	18 of 100 (Routine)
Seymour Shire Depot	Australia	Record daily precipitation	14.2 mm (0.6 in)	18 of 100 (Routine)
Hoyleton	Australia	Record daily precipitation	16.5 mm (0.6 in)	17 of 100 (Routine)
Stansbury	Australia	Record daily precipitation	11.4 mm (0.4 in)	17 of 100 (Routine)
Port Clinton (Yararoo)	Australia	Record daily precipitation	13.2 mm (0.5 in)	17 of 100 (Routine)
Birdwood	Australia	Record daily precipitation	21.1 mm (0.8 in)	17 of 100 (Routine)
Dohne (Sar)	South Africa	Record daily precipitation	3.8 mm (0.15 in)	17 of 100 (Routine)
Warnertown (Willow Lodge)	Australia	Record daily precipitation	20.1 mm (0.8 in)	16 of 100 (Routine)
Ashbourne	Australia	Record daily precipitation	17.8 mm (0.7 in)	16 of 100 (Routine)
Gumeracha	Australia	Record daily precipitation	21.6 mm (0.9 in)	16 of 100 (Routine)
Adelaide (Tea Tree Gully Counc	Australia	Record daily precipitation	15.5 mm (0.6 in)	16 of 100 (Routine)
Kadina	Australia	Record daily precipitation	13.5 mm (0.5 in)	15 of 100 (Routine)
Meningie	Australia	Record daily precipitation	10.7 mm (0.4 in)	15 of 100 (Routine)
Gunnedah Pool	Australia	Record low maximum temperature	13.3 C (55.9 F)	15 of 100 (Routine)
Wanganella (Zara)	Australia	Record daily precipitation	5.1 mm (0.20 in)	15 of 100 (Routine)
Donald Post Office	Australia	Record daily precipitation	7.4 mm (0.29 in)	15 of 100 (Routine)
Wedderburn (Post Office)	Australia	Record daily precipitation	11.9 mm (0.5 in)	15 of 100 (Routine)
Daylesford	Australia	Record daily precipitation	18.0 mm (0.7 in)	15 of 100 (Routine)
Yorketown	Australia	Record daily precipitation	10.7 mm (0.4 in)	14 of 100 (Routine)
Kapunda	Australia	Record daily precipitation	21.6 mm (0.9 in)	14 of 100 (Routine)
Lyndoch (Pewsey Vale)	Australia	Record daily precipitation	26.2 mm (1.0 in)	14 of 100 (Routine)
Macclesfield	Australia	Record daily precipitation	19.8 mm (0.8 in)	14 of 100 (Routine)
Woodside	Australia	Record daily precipitation	17.8 mm (0.7 in)	14 of 100 (Routine)
Glenthompson (Brie Brie)	Australia	Record daily precipitation	10.2 mm (0.4 in)	14 of 100 (Routine)
Bundaleer Forest Reserve	Australia	Record daily precipitation	15.5 mm (0.6 in)	13 of 100 (Routine)
Paskeville	Australia	Record daily precipitation	12.2 mm (0.5 in)	13 of 100 (Routine)
Adelaide (Salisbury Bowling Cl	Australia	Record daily precipitation	12.2 mm (0.5 in)	13 of 100 (Routine)
Gawler (Loos)	Australia	Record daily precipitation	10.2 mm (0.4 in)	13 of 100 (Routine)
Laen	Australia	Record daily precipitation	9.7 mm (0.38 in)	13 of 100 (Routine)
Nhill	Australia	Record daily precipitation	5.3 mm (0.21 in)	13 of 100 (Routine)
Tullaroop Reservoir	Australia	Record daily precipitation	6.9 mm (0.27 in)	13 of 100 (Routine)
Corny Point Lighthouse	Australia	Record daily precipitation	11.4 mm (0.4 in)	12 of 100 (Routine)
Adelaide West Terrace	Australia	Record low maximum temperature	10.6 C (51.1 F)	12 of 100 (Routine)
Kapunda Water Works	Australia	Record daily precipitation	21.6 mm (0.9 in)	12 of 100 (Routine)
Belair (State Flora Nursery)	Australia	Record daily precipitation	13.0 mm (0.5 in)	12 of 100 (Routine)
Sedan (Sandleton)	Australia	Record daily precipitation	12.7 mm (0.5 in)	12 of 100 (Routine)
Macarthur (Glenhuntly)	Australia	Record daily precipitation	15.0 mm (0.6 in)	12 of 100 (Routine)

Counts by Type and Timescale

101 records

Records set or tied on 21 August 1917 by type: Highest daily maximum 2, Lowest daily maximum 8, Lowest daily minimum 1, Heaviest daily rainfall 90.

Records on 21 August 1917 by type
Record type	Records
Highest daily maximum	2
Lowest daily maximum	8
Highest daily minimum	0
Lowest daily minimum	1
Heaviest daily rainfall	90
Heaviest daily snowfall	0
Deepest snow cover	0

Records on 21 August 1917 by timescale: all-time 0, monthly 2, daily 99.

How Much Records Were Beaten By

89 broken records

Margins by which the 89 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 30.2. Ties are not counted.

Top 20 by Significance

21 August 1917

Top 20 records on 21 August 1917 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
21 August 1917	Jamestown, AU	daily rain	34.3 mm (1.4 in)	19.1 mm (0.8 in)	22 years	44 of 100 (Notable)
21 August 1917	Hingham (1), US	monthly rain	104.9 mm (4.1 in)	29.5 mm (1.2 in)	28 years	42 of 100 (Notable)
21 August 1917	Bridgewater, AU	daily rain	45.7 mm (1.8 in)	30.2 mm (1.2 in)	27 years	40 of 100 (Notable)
21 August 1917	Gorlitz, DE	daily rain	43.6 mm (1.7 in)	25.8 mm (1.0 in)	0 years	37 of 100 (Notable)
21 August 1917	Mundoora, AU	daily rain	29.2 mm (1.1 in)	14.0 mm (0.6 in)	8 years	33 of 100 (Routine)
21 August 1917	Port Victoria, AU	daily rain	12.7 mm (0.5 in)	9.4 mm (0.37 in)	22 years	20 of 100 (Routine)
21 August 1917	Edithburgh Post Office, AU	daily rain	13.5 mm (0.5 in)	6.6 mm (0.26 in)	22 years	20 of 100 (Routine)
21 August 1917	Adelaide (Thorndon Park), AU	daily rain	15.0 mm (0.6 in)	6.1 mm (0.24 in)	35 years	20 of 100 (Routine)
21 August 1917	Lobethal, AU	daily rain	24.1 mm (0.9 in)	13.2 mm (0.5 in)	22 years	20 of 100 (Routine)
21 August 1917	North Adelaide, AU	daily rain	18.3 mm (0.7 in)	9.2 mm (0.36 in)	14 years	20 of 100 (Routine)
21 August 1917	Balaklava, AU	daily rain	15.5 mm (0.6 in)	5.8 mm (0.23 in)	30 years	20 of 100 (Routine)
21 August 1917	Plauen, DE	daily rain	19.1 mm (0.8 in)	7.4 mm (0.29 in)	25 years	20 of 100 (Routine)
21 August 1917	Warooka, AU	daily rain	9.7 mm (0.38 in)	3.9 mm (0.15 in)	27 years	20 of 100 (Routine)
21 August 1917	Mitcham Post Office, AU	daily rain	13.2 mm (0.5 in)	6.6 mm (0.26 in)	22 years	20 of 100 (Routine)
21 August 1917	Adelaide (Pooraka), AU	daily rain	12.7 mm (0.5 in)	4.8 mm (0.19 in)	22 years	20 of 100 (Routine)
21 August 1917	Dingo Vale, AU	daily rain	29.2 mm (1.1 in)	14.0 mm (0.6 in)	4 years	20 of 100 (Routine)
21 August 1917	Bendigo Prison, AU	daily rain	10.9 mm (0.4 in)	4.3 mm (0.17 in)	27 years	20 of 100 (Routine)
21 August 1917	Kanmantoo, AU	daily rain	14.0 mm (0.6 in)	5.1 mm (0.20 in)	22 years	19 of 100 (Routine)
21 August 1917	Mount Barker, AU	daily rain	25.7 mm (1.0 in)	9.7 mm (0.38 in)	4 years	19 of 100 (Routine)
21 August 1917	Truro, AU	daily rain	22.1 mm (0.9 in)	6.6 mm (0.26 in)	22 years	19 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

1800 to 1917

Records set or tied on this calendar date in each year from 1800 to 1917. 1917 had 101 records.

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

Records on 08-21 in each year
Year	Records
1800	1
1802	1
1804	1
1807	1
1816	1
1818	1
1832	1
1834	1
1839	3
1843	1
1847	1
1849	3
1850	1
1851	2
1863	1
1866	1
1867	2
1870	3
1871	2
1872	1
1873	1
1876	1
1877	2
1879	2
1884	2
1885	5
1886	1
1887	5
1888	2
1889	3
1890	4
1891	2
1893	4
1894	8
1895	3
1896	2
1897	4
1898	4
1899	7
1900	4
1901	9
1902	8
1903	6
1904	8
1905	4
1906	22
1907	20
1908	13
1909	17
1910	33
1911	19
1912	50
1913	37
1914	24
1915	21
1916	106
1917	101
1918	202
1919	19
1920	59
1921	34
1922	58
1923	111
1924	135
1925	220
1926	227
1927	228
1928	110
1929	234
1930	297
1931	277
1932	264
1933	328
1934	320
1935	318
1936	807
1937	762
1938	239
1939	630
1940	683
1941	180
1942	415
1943	438
1944	346
1945	544
1946	390
1947	954
1948	305
1949	508
1950	958
1951	699
1952	368
1953	331
1954	497
1955	885
1956	701
1957	490
1958	389
1959	704
1960	490
1961	644
1962	469
1963	338
1964	794
1965	455
1966	661
1967	541
1968	1,014
1969	650
1970	373
1971	660
1972	441
1973	438
1974	564
1975	545
1976	756
1977	764
1978	445
1979	778
1980	904
1981	1,015
1982	769
1983	1,407
1984	975
1985	623
1986	1,166
1987	740
1988	889
1989	828
1990	910
1991	828
1992	957
1993	698
1994	968
1995	962
1996	950
1997	1,291
1998	948
1999	717
2000	861
2001	797
2002	965
2003	1,241
2004	1,585
2005	1,071
2006	797
2007	1,829
2008	1,012
2009	1,319
2010	1,155
2011	1,022
2012	990
2013	513
2014	624
2015	651
2016	890
2017	347
2018	816
2019	631
2020	1,147
2021	767
2022	917
2023	1,826
2024	777
2025	1,230
2026	1,289

Download the Data

Data for records on 1917-08-21: 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 5	61
5 to 10	20
10 to 15	4
15 to 20	1
20 to 25	0
25 to 30	2
30 to 35	1