Weather Records on 20 September 1917

100 weather records were set or tied worldwide on 20 September 1917. Highest significance: Wollun, AU.

Key Facts for 20 September 1917

On 20 September 1917, 100 weather records were set or tied at long-record stations worldwide.
26 were record highs and 0 were record lows, counting maximum and minimum temperature.
By timescale, 0 were all-time records, 8 monthly and 92 daily.
Wollun set a monthly record daily precipitation of 109.2 mm (4.3 in) on 20 September 1917.
Across 156 earlier years (1812 to 2026) the same calendar date averaged 444 records.

Record Map

100 stations

100 station records on 20 September 1917 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 20 September 1917: highest significance records shown on the map
Station	Country	Type	Value	Significance
Wollun	Australia	Record daily precipitation	109.2 mm (4.3 in)	55 of 100 (Notable)
Lue Station	Australia	Record daily precipitation	54.1 mm (2.1 in)	53 of 100 (Notable)
Dural Public School	Australia	Record daily precipitation	81.3 mm (3.2 in)	52 of 100 (Notable)
Mount Victoria (Mt Victoria (S	Australia	Record daily precipitation	77.2 mm (3.0 in)	51 of 100 (Notable)
Coolah (Binnia St)	Australia	Record daily precipitation	61.0 mm (2.4 in)	50 of 100 (Notable)
Sydney (Observatory Hill)	Australia	Record daily precipitation	77.7 mm (3.1 in)	49 of 100 (Notable)
Glenfield (Macquarie)	Australia	Record daily precipitation	38.1 mm (1.5 in)	48 of 100 (Notable)
Botany No.1 Dam	Australia	Record daily precipitation	75.4 mm (3.0 in)	47 of 100 (Notable)
Penshurst (Gresford)	Australia	Record daily precipitation	71.4 mm (2.8 in)	46 of 100 (Notable)
Mudgee (George Street)	Australia	Record daily precipitation	38.1 mm (1.5 in)	45 of 100 (Notable)
Moss Vale (Hoskins Street)	Australia	Record daily precipitation	82.6 mm (3.3 in)	44 of 100 (Notable)
Wyong (Wyong Golf Club)	Australia	Record daily precipitation	83.1 mm (3.3 in)	43 of 100 (Notable)
Burwood 1	Australia	Record daily precipitation	55.4 mm (2.2 in)	43 of 100 (Notable)
Katoomba (Murri St)	Australia	Record daily precipitation	88.9 mm (3.5 in)	42 of 100 (Notable)
Gosford (Gertrude Place)	Australia	Record daily precipitation	115.1 mm (4.5 in)	41 of 100 (Notable)
Campbelltown 1	Australia	Record daily precipitation	32.0 mm (1.3 in)	40 of 100 (Notable)
Jamberoo (Lorna)	Australia	Record daily precipitation	130.8 mm (5.1 in)	39 of 100 (Notable)
Wingen (Murrulla)	Australia	Record daily precipitation	50.8 mm (2.0 in)	37 of 100 (Notable)
Prospect Reservoir	Australia	Record daily precipitation	38.6 mm (1.5 in)	36 of 100 (Notable)
Premer Post Office	Australia	Record daily precipitation	47.8 mm (1.9 in)	35 of 100 (Notable)
Binnaway (Hawthorne)	Australia	Record daily precipitation	35.6 mm (1.4 in)	35 of 100 (Notable)
Crown St. Reservoir	Australia	Record daily precipitation	48.3 mm (1.9 in)	33 of 100 (Routine)
Richmond - Uws Hawkesbury	Australia	Record daily precipitation	36.3 mm (1.4 in)	33 of 100 (Routine)
Lithgow (Cooerwull)	Australia	Record daily precipitation	55.9 mm (2.2 in)	32 of 100 (Routine)
Gundy (Miller St)	Australia	Record daily precipitation	69.6 mm (2.7 in)	31 of 100 (Routine)
Berry Masonic Village	Australia	Record daily precipitation	77.7 mm (3.1 in)	29 of 100 (Routine)
Wien	Austria	Record high maximum temperature	29.3 C (84.7 F)	29 of 100 (Routine)
Burrundulla	Australia	Record daily precipitation	40.6 mm (1.6 in)	28 of 100 (Routine)
Rotherwood	Australia	Record daily precipitation	29.5 mm (1.2 in)	27 of 100 (Routine)
Belltrees Homestead	Australia	Record daily precipitation	34.3 mm (1.4 in)	25 of 100 (Routine)
Rylstone (Ilford Rd)	Australia	Record daily precipitation	45.2 mm (1.8 in)	24 of 100 (Routine)
Bowral Post Office	Australia	Record daily precipitation	59.7 mm (2.4 in)	23 of 100 (Routine)
Willow Tree (Valais)	Australia	Record daily precipitation	42.7 mm (1.7 in)	22 of 100 (Routine)
Springwood Bowling Club	Australia	Record daily precipitation	47.0 mm (1.9 in)	22 of 100 (Routine)
Epping Chester Street	Australia	Record daily precipitation	69.3 mm (2.7 in)	22 of 100 (Routine)
Cataract River	Australia	Record daily precipitation	41.9 mm (1.6 in)	22 of 100 (Routine)
Munchen-Nymphenburg	Germany	Record high minimum temperature	17.1 C (62.8 F)	22 of 100 (Routine)
Walcha Post Office	Australia	Record daily precipitation	67.3 mm (2.6 in)	21 of 100 (Routine)
Oktjabrskij-Gorodok	Russia	Record daily precipitation	18.7 mm (0.7 in)	20 of 100 (Routine)
Tenterden	Australia	Record daily precipitation	28.7 mm (1.1 in)	20 of 100 (Routine)
Ellerston	Australia	Record daily precipitation	53.6 mm (2.1 in)	20 of 100 (Routine)
Milton Post Office	Australia	Record daily precipitation	52.1 mm (2.1 in)	20 of 100 (Routine)
Boggabri Post Office	Australia	Record daily precipitation	25.7 mm (1.0 in)	19 of 100 (Routine)
Murrurundi Post Office	Australia	Record daily precipitation	39.9 mm (1.6 in)	19 of 100 (Routine)
Nowra Council Offices	Australia	Record daily precipitation	49.8 mm (2.0 in)	19 of 100 (Routine)
Innsbruck	Austria	Record high maximum temperature	26.0 C (78.8 F)	19 of 100 (Routine)
Plauen	Germany	Record high maximum temperature	25.1 C (77.2 F)	19 of 100 (Routine)
Zagreb-Gric	Croatia	Record high maximum temperature	28.8 C (83.8 F)	19 of 100 (Routine)
Freiburg	Germany	Record high minimum temperature	17.6 C (63.7 F)	18 of 100 (Routine)
Branxton Post Office	Australia	Record daily precipitation	18.0 mm (0.7 in)	17 of 100 (Routine)
Menangle Jmai	Australia	Record daily precipitation	26.4 mm (1.0 in)	17 of 100 (Routine)
Mittagong (Beatrice Street)	Australia	Record daily precipitation	48.5 mm (1.9 in)	17 of 100 (Routine)
Hohenpeissenberg	Germany	Record high maximum temperature	23.2 C (73.8 F)	17 of 100 (Routine)
Nurnberg	Germany	Record high maximum temperature	25.2 C (77.4 F)	17 of 100 (Routine)
Scone (Philip Street)	Australia	Record daily precipitation	19.1 mm (0.8 in)	16 of 100 (Routine)
Emu Plains	Australia	Record daily precipitation	32.0 mm (1.3 in)	16 of 100 (Routine)
Hohenpeissenberg	Germany	Record high minimum temperature	17.8 C (64.0 F)	16 of 100 (Routine)
Port Victoria	Australia	Record daily precipitation	4.1 mm (0.16 in)	15 of 100 (Routine)
Waverley (Belltrees 2)	Australia	Record daily precipitation	29.5 mm (1.2 in)	15 of 100 (Routine)
Llangollen	Australia	Record daily precipitation	15.7 mm (0.6 in)	15 of 100 (Routine)

Counts by Type and Timescale

100 records

Records set or tied on 20 September 1917 by type: Highest daily maximum 13, Highest daily minimum 13, Heaviest daily rainfall 74.

Records on 20 September 1917 by type
Record type	Records
Highest daily maximum	13
Lowest daily maximum	0
Highest daily minimum	13
Lowest daily minimum	0
Heaviest daily rainfall	74
Heaviest daily snowfall	0
Deepest snow cover	0

Records on 20 September 1917 by timescale: all-time 0, monthly 8, daily 92.

How Much Records Were Beaten By

96 broken records

Margins by which the 96 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 67.1. Ties are not counted.

Top 20 by Significance

20 September 1917

Top 20 records on 20 September 1917 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
20 September 1917	Wollun, AU	monthly rain	109.2 mm (4.3 in)	58.4 mm (2.3 in)	9 years	55 of 100 (Notable)
20 September 1917	Lue Station, AU	daily rain	54.1 mm (2.1 in)	43.9 mm (1.7 in)	33 years	53 of 100 (Notable)
20 September 1917	Dural Public School, AU	daily rain	81.3 mm (3.2 in)	53.9 mm (2.1 in)	25 years	52 of 100 (Notable)
20 September 1917	Mount Victoria (Mt Victoria (S, AU	daily rain	77.2 mm (3.0 in)	62.5 mm (2.5 in)	24 years	51 of 100 (Notable)
20 September 1917	Coolah (Binnia St), AU	daily rain	61.0 mm (2.4 in)	43.2 mm (1.7 in)	25 years	50 of 100 (Notable)
20 September 1917	Sydney (Observatory Hill), AU	daily rain	77.7 mm (3.1 in)	56.1 mm (2.2 in)	12 years	49 of 100 (Notable)
20 September 1917	Glenfield (Macquarie), AU	daily rain	38.1 mm (1.5 in)	34.0 mm (1.3 in)	16 years	48 of 100 (Notable)
20 September 1917	Botany No.1 Dam, AU	daily rain	75.4 mm (3.0 in)	58.6 mm (2.3 in)	12 years	47 of 100 (Notable)
20 September 1917	Penshurst (Gresford), AU	daily rain	71.4 mm (2.8 in)	44.7 mm (1.8 in)	27 years	46 of 100 (Notable)
20 September 1917	Mudgee (George Street), AU	daily rain	38.1 mm (1.5 in)	29.5 mm (1.2 in)	39 years	45 of 100 (Notable)
20 September 1917	Moss Vale (Hoskins Street), AU	daily rain	82.6 mm (3.3 in)	48.6 mm (1.9 in)	2 years	44 of 100 (Notable)
20 September 1917	Wyong (Wyong Golf Club), AU	daily rain	83.1 mm (3.3 in)	67.1 mm (2.6 in)	2 years	43 of 100 (Notable)
20 September 1917	Burwood 1, AU	daily rain	55.4 mm (2.2 in)	45.2 mm (1.8 in)	3 years	43 of 100 (Notable)
20 September 1917	Katoomba (Murri St), AU	daily rain	88.9 mm (3.5 in)	49.8 mm (2.0 in)	12 years	42 of 100 (Notable)
20 September 1917	Gosford (Gertrude Place), AU	daily rain	115.1 mm (4.5 in)	62.5 mm (2.5 in)	28 years	41 of 100 (Notable)
20 September 1917	Campbelltown 1, AU	daily rain	32.0 mm (1.3 in)	22.9 mm (0.9 in)	24 years	40 of 100 (Notable)
20 September 1917	Jamberoo (Lorna), AU	monthly rain	130.8 mm (5.1 in)	38.1 mm (1.5 in)	3 years	39 of 100 (Notable)
20 September 1917	Wingen (Murrulla), AU	daily rain	50.8 mm (2.0 in)	29.5 mm (1.2 in)	2 years	37 of 100 (Notable)
20 September 1917	Prospect Reservoir, AU	daily rain	38.6 mm (1.5 in)	24.1 mm (0.9 in)	25 years	36 of 100 (Notable)
20 September 1917	Premer Post Office, AU	daily rain	47.8 mm (1.9 in)	30.5 mm (1.2 in)	2 years	35 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

1812 to 1917

Records set or tied on this calendar date in each year from 1812 to 1917. 1917 had 100 records.

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

Records on 09-20 in each year
Year	Records
1812	1
1837	1
1840	1
1844	1
1848	2
1851	1
1852	1
1854	2
1855	1
1856	2
1859	2
1860	1
1862	1
1870	1
1871	2
1882	2
1883	1
1884	1
1886	2
1887	1
1888	2
1889	8
1891	4
1893	5
1894	1
1895	2
1896	1
1897	16
1898	4
1899	1
1900	2
1901	3
1902	3
1903	3
1904	12
1905	8
1906	22
1907	11
1908	24
1909	10
1910	8
1911	21
1912	34
1913	48
1914	28
1915	239
1916	28
1917	100
1918	59
1919	55
1920	64
1921	40
1922	52
1923	249
1924	329
1925	330
1926	129
1927	169
1928	144
1929	373
1930	102
1931	564
1932	270
1933	223
1934	349
1935	201
1936	133
1937	385
1938	506
1939	312
1940	591
1941	582
1942	436
1943	419
1944	466
1945	406
1946	766
1947	460
1948	454
1949	268
1950	435
1951	267
1952	434
1953	479
1954	628
1955	625
1956	985
1957	514
1958	410
1959	489
1960	352
1961	384
1962	707
1963	290
1964	482
1965	1,180
1966	414
1967	449
1968	617
1969	604
1970	591
1971	884
1972	582
1973	569
1974	771
1975	527
1976	375
1977	776
1978	1,216
1979	767
1980	567
1981	979
1982	911
1983	1,958
1984	895
1985	730
1986	743
1987	856
1988	698
1989	968
1990	743
1991	1,835
1992	718
1993	1,031
1994	788
1995	1,374
1996	1,077
1997	1,282
1998	1,157
1999	923
2000	908
2001	821
2002	845
2003	910
2004	1,156
2005	960
2006	732
2007	645
2008	648
2009	715
2010	1,497
2011	650
2012	549
2013	595
2014	577
2015	439
2016	778
2017	920
2018	1,020
2019	835
2020	630
2021	565
2022	786
2023	482
2024	596
2025	877
2026	682

Download the Data

Data for records on 1917-09-20: 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 2026-10-17 (17 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-15. Last revised 15 October 2026 (2026-10-15).

Margin	Records
0 to 10	55
10 to 20	10
20 to 30	12
30 to 40	5
40 to 50	7
50 to 60	4
60 to 70	3