Weather Records on 18 August 1917

70 weather records were set or tied worldwide on 18 August 1917. Highest significance: Runnymede, AU.

Key Facts for 18 August 1917

On 18 August 1917, 70 weather records were set or tied at long-record stations worldwide.
13 were record highs and 3 were record lows, counting maximum and minimum temperature.
By timescale, 0 were all-time records, 1 monthly and 69 daily.
Runnymede set a daily record precipitation of 25.4 mm (1.0 in) on 18 August 1917.
Across 171 earlier years (1797 to 2026) the same calendar date averaged 443 records.

Record Map

70 stations

70 station records on 18 August 1917 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 18 August 1917: highest significance records shown on the map
Station	Country	Type	Value	Significance
Runnymede	Australia	Record daily precipitation	25.4 mm (1.0 in)	47 of 100 (Notable)
Lugansk	Ukraine	Record daily precipitation	59.8 mm (2.4 in)	29 of 100 (Routine)
Clare (Hill River)	Australia	Record daily precipitation	32.5 mm (1.3 in)	28 of 100 (Routine)
The Olives	Australia	Record daily precipitation	26.7 mm (1.1 in)	27 of 100 (Routine)
Pine Lodge 1	Australia	Record daily precipitation	19.8 mm (0.8 in)	20 of 100 (Routine)
Binya Post Office	Australia	Record daily precipitation	11.4 mm (0.4 in)	20 of 100 (Routine)
Macclesfield	Australia	Record daily precipitation	15.0 mm (0.6 in)	20 of 100 (Routine)
Walcha Post Office	Australia	Record daily precipitation	12.2 mm (0.5 in)	20 of 100 (Routine)
Manfred	Australia	Record daily precipitation	9.4 mm (0.37 in)	20 of 100 (Routine)
Clunes	Australia	Record daily precipitation	14.7 mm (0.6 in)	20 of 100 (Routine)
Bridgewater	Australia	Record daily precipitation	18.5 mm (0.7 in)	20 of 100 (Routine)
Litchfield	Australia	Record daily precipitation	6.6 mm (0.26 in)	20 of 100 (Routine)
Cape Otway Lighthouse	Australia	Record high minimum temperature	11.7 C (53.1 F)	20 of 100 (Routine)
Binya (Merribee)	Australia	Record daily precipitation	14.0 mm (0.6 in)	19 of 100 (Routine)
Warnertown (Willow Lodge)	Australia	Record daily precipitation	10.7 mm (0.4 in)	18 of 100 (Routine)
Adelaide (Tea Tree Gully Counc	Australia	Record daily precipitation	11.4 mm (0.4 in)	18 of 100 (Routine)
Woodside	Australia	Record daily precipitation	11.9 mm (0.5 in)	18 of 100 (Routine)
Halden	Norway	Record daily precipitation	27.0 mm (1.1 in)	18 of 100 (Routine)
Wooroonook	Australia	Record daily precipitation	14.7 mm (0.6 in)	17 of 100 (Routine)
Ashbourne	Australia	Record daily precipitation	15.7 mm (0.6 in)	16 of 100 (Routine)
Naracoorte	Australia	Record daily precipitation	7.6 mm (0.30 in)	16 of 100 (Routine)
Melton	Australia	Record daily precipitation	8.9 mm (0.35 in)	16 of 100 (Routine)
Urawilkie	Australia	Record daily precipitation	9.4 mm (0.37 in)	15 of 100 (Routine)
Bjornholt	Norway	Record daily precipitation	46.8 mm (1.8 in)	15 of 100 (Routine)
Bramfield Post Office	Australia	Record daily precipitation	10.2 mm (0.4 in)	14 of 100 (Routine)
Boolcoomatta	Australia	Record daily precipitation	2.3 mm (0.09 in)	14 of 100 (Routine)
Fredericton Unb	Canada	Record daily precipitation	35.1 mm (1.4 in)	14 of 100 (Routine)
Watervale	Australia	Record daily precipitation	10.2 mm (0.4 in)	13 of 100 (Routine)
Wellington East	Australia	Record daily precipitation	6.4 mm (0.25 in)	13 of 100 (Routine)
Buangor 1	Australia	Record daily precipitation	12.7 mm (0.5 in)	13 of 100 (Routine)
Nicosia	Cyprus	Record high maximum temperature	43.3 C (109.9 F)	13 of 100 (Routine)
Karesuando	Sweden	Record high minimum temperature	13.0 C (55.4 F)	13 of 100 (Routine)
Elliston	Australia	Record daily precipitation	10.2 mm (0.4 in)	12 of 100 (Routine)
Adelaide (Thorndon Park)	Australia	Record daily precipitation	9.1 mm (0.36 in)	12 of 100 (Routine)
Kingston SE	Australia	Record daily precipitation	7.6 mm (0.30 in)	12 of 100 (Routine)
Millicent	Australia	Record daily precipitation	7.6 mm (0.30 in)	12 of 100 (Routine)
Budgery	Australia	Record daily precipitation	7.4 mm (0.29 in)	12 of 100 (Routine)
Carabost	Australia	Record daily precipitation	21.6 mm (0.9 in)	12 of 100 (Routine)
Minimay (Booroopki)	Australia	Record daily precipitation	5.1 mm (0.20 in)	12 of 100 (Routine)
Wrixum/Fohr	Germany	Record high minimum temperature	17.0 C (62.6 F)	12 of 100 (Routine)
Bordertown	Australia	Record daily precipitation	7.1 mm (0.28 in)	11 of 100 (Routine)
Swift Current	Canada	Record high maximum temperature	33.3 C (91.9 F)	11 of 100 (Routine)
Malin Head	Ireland	Record daily precipitation	12.3 mm (0.5 in)	11 of 100 (Routine)
Anticosti SW Point	Canada	Record high minimum temperature	16.1 C (61.0 F)	10 of 100 (Routine)
Sarna	Sweden	Record daily precipitation	10.5 mm (0.4 in)	10 of 100 (Routine)
Miltalie (Poodra)	Australia	Record daily precipitation	3.3 mm (0.13 in)	9 of 100 (Routine)
Adelaide (Salisbury Bowling Cl	Australia	Record daily precipitation	7.4 mm (0.29 in)	9 of 100 (Routine)
Stromsfoss Sluse	Norway	Record daily precipitation	20.0 mm (0.8 in)	9 of 100 (Routine)
Halmstad	Sweden	Record high minimum temperature	15.5 C (59.9 F)	9 of 100 (Routine)
Beachport	Australia	Record daily precipitation	9.4 mm (0.37 in)	8 of 100 (Routine)
Merungle	Australia	Record daily precipitation	6.6 mm (0.26 in)	8 of 100 (Routine)
Mitcham Post Office	Australia	Record daily precipitation	9.4 mm (0.37 in)	6 of 100 (Routine)
Battunga	Australia	Record daily precipitation	7.1 mm (0.28 in)	6 of 100 (Routine)
Kingscote	Australia	Record daily precipitation	5.3 mm (0.21 in)	4 of 100 (Routine)
North Adelaide	Australia	Record daily precipitation	8.6 mm (0.34 in)	4 of 100 (Routine)
Adelaide (Pooraka)	Australia	Record daily precipitation	6.6 mm (0.26 in)	4 of 100 (Routine)
Meadows	Australia	Record daily precipitation	9.4 mm (0.37 in)	4 of 100 (Routine)
Echunga Golf Course	Australia	Record daily precipitation	8.1 mm (0.32 in)	3 of 100 (Routine)
Penola Post Office	Australia	Record daily precipitation	11.7 mm (0.5 in)	3 of 100 (Routine)
Yarmouth	Canada	Record high minimum temperature	15.6 C (60.1 F)	3 of 100 (Routine)

Counts by Type and Timescale

70 records

Records set or tied on 18 August 1917 by type: Highest daily maximum 3, Highest daily minimum 10, Lowest daily minimum 3, Heaviest daily rainfall 54.

Records on 18 August 1917 by type
Record type	Records
Highest daily maximum	3
Lowest daily maximum	0
Highest daily minimum	10
Lowest daily minimum	3
Heaviest daily rainfall	54
Heaviest daily snowfall	0
Deepest snow cover	0

Records on 18 August 1917 by timescale: all-time 0, monthly 1, daily 69.

How Much Records Were Beaten By

59 broken records

Margins by which the 59 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 21.6. Ties are not counted.

Top 20 by Significance

18 August 1917

Top 20 records on 18 August 1917 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
18 August 1917	Runnymede, AU	daily rain	25.4 mm (1.0 in)	21.6 mm (0.9 in)	16 years	47 of 100 (Notable)
18 August 1917	Lugansk, UA	monthly rain	59.8 mm (2.4 in)	10.6 mm (0.4 in)	14 years	29 of 100 (Routine)
18 August 1917	Clare (Hill River), AU	daily rain	32.5 mm (1.3 in)	17.8 mm (0.7 in)	11 years	28 of 100 (Routine)
18 August 1917	The Olives, AU	daily rain	26.7 mm (1.1 in)	14.5 mm (0.6 in)	11 years	27 of 100 (Routine)
18 August 1917	Pine Lodge 1, AU	daily rain	19.8 mm (0.8 in)	16.8 mm (0.7 in)	29 years	20 of 100 (Routine)
18 August 1917	Binya Post Office, AU	daily rain	11.4 mm (0.4 in)	11.4 mm (0.4 in)	40 years	20 of 100 (Routine)
18 August 1917	Macclesfield, AU	daily rain	15.0 mm (0.6 in)	9.9 mm (0.39 in)	30 years	20 of 100 (Routine)
18 August 1917	Walcha Post Office, AU	daily rain	12.2 mm (0.5 in)	9.7 mm (0.38 in)	34 years	20 of 100 (Routine)
18 August 1917	Manfred, AU	daily rain	9.4 mm (0.37 in)	7.4 mm (0.29 in)	30 years	20 of 100 (Routine)
18 August 1917	Clunes, AU	daily rain	14.7 mm (0.6 in)	6.1 mm (0.24 in)	26 years	20 of 100 (Routine)
18 August 1917	Bridgewater, AU	daily rain	18.5 mm (0.7 in)	10.9 mm (0.4 in)	28 years	20 of 100 (Routine)
18 August 1917	Litchfield, AU	daily rain	6.6 mm (0.26 in)	4.3 mm (0.17 in)	33 years	20 of 100 (Routine)
18 August 1917	Cape Otway Lighthouse, AU	daily high min	11.7 C (53.1 F)	1.1 C (2.0 F)	33 years	20 of 100 (Routine)
18 August 1917	Binya (Merribee), AU	daily rain	14.0 mm (0.6 in)	9.7 mm (0.38 in)	25 years	19 of 100 (Routine)
18 August 1917	Warnertown (Willow Lodge), AU	daily rain	10.7 mm (0.4 in)	5.6 mm (0.22 in)	25 years	18 of 100 (Routine)
18 August 1917	Adelaide (Tea Tree Gully Counc, AU	daily rain	11.4 mm (0.4 in)	4.8 mm (0.19 in)	28 years	18 of 100 (Routine)
18 August 1917	Woodside, AU	daily rain	11.9 mm (0.5 in)	5.5 mm (0.22 in)	30 years	18 of 100 (Routine)
18 August 1917	Halden, NO	daily rain	27.0 mm (1.1 in)	9.0 mm (0.35 in)	14 years	18 of 100 (Routine)
18 August 1917	Wooroonook, AU	daily rain	14.7 mm (0.6 in)	7.3 mm (0.29 in)	12 years	17 of 100 (Routine)
18 August 1917	Ashbourne, AU	daily rain	15.7 mm (0.6 in)	9.3 mm (0.37 in)	0 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

1797 to 1917

Records set or tied on this calendar date in each year from 1797 to 1917. 1917 had 70 records.

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

Records on 08-18 in each year
Year	Records
1797	2
1805	1
1816	1
1827	1
1829	1
1830	1
1833	1
1841	1
1844	1
1845	3
1846	1
1847	1
1849	1
1851	1
1852	1
1853	1
1854	2
1855	1
1856	1
1861	1
1864	2
1866	1
1868	2
1869	1
1870	2
1872	1
1873	1
1875	3
1876	1
1878	1
1879	2
1883	3
1885	3
1886	3
1887	3
1888	2
1889	1
1890	1
1891	2
1892	6
1893	4
1894	4
1895	1
1898	4
1899	6
1900	2
1901	10
1902	8
1903	6
1904	8
1905	10
1906	40
1907	7
1908	21
1909	24
1910	16
1911	11
1912	21
1913	43
1914	37
1915	60
1916	71
1917	70
1918	53
1919	34
1920	51
1921	39
1922	129
1923	90
1924	225
1925	300
1926	168
1927	269
1928	141
1929	181
1930	150
1931	241
1932	382
1933	431
1934	638
1935	424
1936	766
1937	308
1938	243
1939	381
1940	434
1941	467
1942	333
1943	738
1944	325
1945	400
1946	416
1947	958
1948	315
1949	393
1950	683
1951	355
1952	405
1953	323
1954	622
1955	795
1956	580
1957	380
1958	580
1959	537
1960	599
1961	415
1962	428
1963	760
1964	443
1965	525
1966	573
1967	623
1968	795
1969	530
1970	597
1971	381
1972	493
1973	734
1974	639
1975	844
1976	917
1977	1,112
1978	854
1979	1,309
1980	771
1981	1,386
1982	563
1983	1,420
1984	600
1985	765
1986	861
1987	1,609
1988	1,351
1989	952
1990	920
1991	533
1992	1,497
1993	706
1994	1,027
1995	1,882
1996	760
1997	1,191
1998	923
1999	888
2000	1,183
2001	1,036
2002	1,306
2003	860
2004	1,050
2005	865
2006	842
2007	1,116
2008	1,265
2009	839
2010	1,167
2011	1,239
2012	1,247
2013	752
2014	751
2015	880
2016	704
2017	565
2018	462
2019	615
2020	1,541
2021	1,118
2022	1,237
2023	1,094
2024	696
2025	455
2026	545

Download the Data

Data for records on 1917-08-18: 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 5	38
5 to 10	12
10 to 15	6
15 to 20	2
20 to 25	1