Weather Records on 17 September 1975

478 weather records were set or tied worldwide on 17 September 1975. Highest significance: Lajas Substn, PR.

Key Facts for 17 September 1975

On 17 September 1975, 478 weather records were set or tied at long-record stations worldwide.
177 were record highs and 92 were record lows, counting maximum and minimum temperature.
By timescale, 4 were all-time records, 19 monthly and 455 daily.
Lajas Substn set an all-time record daily precipitation of 311.4 mm (12.3 in) on 17 September 1975.
Across 164 earlier years (1796 to 2026) the same calendar date averaged 422 records.

Record Map

478 stations

478 station records on 17 September 1975 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 17 September 1975: highest significance records shown on the map
Station	Country	Type	Value	Significance
Lajas Substn	Puerto Rico [United States]	Record daily precipitation	311.4 mm (12.3 in)	70 of 100 (Major)
Arecibo 3 ESE	Puerto Rico [United States]	Record daily precipitation	228.6 mm (9.0 in)	66 of 100 (Major)
Isabela Substn	Puerto Rico [United States]	Record daily precipitation	123.7 mm (4.9 in)	66 of 100 (Major)
Eberys	Australia	Record daily precipitation	54.2 mm (2.1 in)	58 of 100 (Notable)
Juana Diaz Camp	Puerto Rico [United States]	Record daily precipitation	191.5 mm (7.5 in)	54 of 100 (Notable)
Moosomin	Canada	Record daily precipitation	34.5 mm (1.4 in)	53 of 100 (Notable)
Boissevain	Canada	Record daily precipitation	28.4 mm (1.1 in)	51 of 100 (Notable)
Mayaguez City	Puerto Rico [United States]	Record daily precipitation	170.2 mm (6.7 in)	49 of 100 (Notable)
Cartwright	Canada	Record daily precipitation	29.2 mm (1.1 in)	48 of 100 (Notable)
Ninette	Canada	Record daily precipitation	44.7 mm (1.8 in)	48 of 100 (Notable)
Hohenpeissenberg	Germany	Record high minimum temperature	21.2 C (70.2 F)	47 of 100 (Notable)
Pierson	Canada	Record daily precipitation	27.9 mm (1.1 in)	46 of 100 (Notable)
Garzas	Puerto Rico [United States]	Record daily precipitation	174.0 mm (6.9 in)	46 of 100 (Notable)
Borinquen AP	Puerto Rico [United States]	Record daily precipitation	86.4 mm (3.4 in)	46 of 100 (Notable)
Humacao 2 SSE	Puerto Rico [United States]	Record daily precipitation	132.6 mm (5.2 in)	45 of 100 (Notable)
Juncos 1 SE	Puerto Rico [United States]	Record daily precipitation	91.2 mm (3.6 in)	45 of 100 (Notable)
Saentis	Switzerland	Record high maximum temperature	17.0 C (62.6 F)	45 of 100 (Notable)
Ruy Barbosa	Brazil	Record daily precipitation	35.0 mm (1.4 in)	44 of 100 (Notable)
Indian Head Cda	Canada	Record daily precipitation	30.0 mm (1.2 in)	44 of 100 (Notable)
Russell	Canada	Record daily precipitation	34.3 mm (1.4 in)	44 of 100 (Notable)
Murchison	Australia	Record daily precipitation	35.4 mm (1.4 in)	43 of 100 (Notable)
Whitlands (Burder's Lane)	Australia	Record daily precipitation	65.8 mm (2.6 in)	43 of 100 (Notable)
Weissenburg	Germany	Record high minimum temperature	16.7 C (62.1 F)	43 of 100 (Notable)
Medina	United States	Record daily precipitation	38.4 mm (1.5 in)	43 of 100 (Notable)
Ponce 4 E	Puerto Rico [United States]	Record daily precipitation	197.6 mm (7.8 in)	42 of 100 (Notable)
San Juan City	Puerto Rico [United States]	Record daily precipitation	54.6 mm (2.1 in)	42 of 100 (Notable)
Burnie (Round Hill)	Australia	Record daily precipitation	61.8 mm (2.4 in)	41 of 100 (Notable)
Lares	Puerto Rico [United States]	Record daily precipitation	153.7 mm (6.1 in)	41 of 100 (Notable)
Ridgley	Australia	Record daily precipitation	62.0 mm (2.4 in)	40 of 100 (Notable)
Dublin Phoenix Park	Ireland	Record daily precipitation	37.0 mm (1.5 in)	40 of 100 (Notable)
Dillingham FAA AP	United States	Record daily precipitation	42.7 mm (1.7 in)	40 of 100 (Notable)
Orly	France	Record daily precipitation	31.7 mm (1.2 in)	38 of 100 (Notable)
Nurnberg	Germany	Record high maximum temperature	31.0 C (87.8 F)	38 of 100 (Notable)
Isabela Substn	Puerto Rico [United States]	Record low maximum temperature	24.4 C (75.9 F)	38 of 100 (Notable)
Le Bourget	France	Record daily precipitation	33.3 mm (1.3 in)	37 of 100 (Notable)
Myrrhee (Joelyn)	Australia	Record daily precipitation	45.2 mm (1.8 in)	36 of 100 (Notable)
Murrindindi	Australia	Record daily precipitation	32.0 mm (1.3 in)	36 of 100 (Notable)
Moorleah (Preolenna Road)	Australia	Record daily precipitation	70.4 mm (2.8 in)	36 of 100 (Notable)
Corozal Substn	Puerto Rico [United States]	Record low maximum temperature	23.9 C (75.0 F)	36 of 100 (Notable)
Col du Grand St-Bernard	Switzerland	Record high maximum temperature	15.5 C (59.9 F)	36 of 100 (Notable)
Songkhla	Thailand	Record daily precipitation	68.0 mm (2.7 in)	36 of 100 (Notable)
Strathbogie North	Australia	Record daily precipitation	50.0 mm (2.0 in)	35 of 100 (Notable)
Ulverstone (Knights Road)	Australia	Record daily precipitation	49.8 mm (2.0 in)	35 of 100 (Notable)
Virden	Canada	Record daily precipitation	29.0 mm (1.1 in)	35 of 100 (Notable)
Plauen	Germany	Record high minimum temperature	16.9 C (62.4 F)	35 of 100 (Notable)
Salekhard	Russia	Record high minimum temperature	10.8 C (51.4 F)	35 of 100 (Notable)
Nardy	Australia	Record daily precipitation	93.0 mm (3.7 in)	34 of 100 (Routine)
Calhoun 2 N	United States	Record daily precipitation	43.2 mm (1.7 in)	34 of 100 (Routine)
Wagga Wagga Agricultural Insti	Australia	Record high minimum temperature	15.1 C (59.2 F)	33 of 100 (Routine)
Whitfield	Australia	Record daily precipitation	60.0 mm (2.4 in)	33 of 100 (Routine)
Whitewood	Canada	Record daily precipitation	35.1 mm (1.4 in)	33 of 100 (Routine)
Irishtown	Australia	Record daily precipitation	49.0 mm (1.9 in)	32 of 100 (Routine)
Oberstdorf	Germany	Record high maximum temperature	33.3 C (91.9 F)	32 of 100 (Routine)
Fenn Rs	United States	Record daily precipitation	30.0 mm (1.2 in)	32 of 100 (Routine)
Dandongadale (Mountain View)	Australia	Record daily precipitation	58.0 mm (2.3 in)	30 of 100 (Routine)
Marseille Obs. Palais-Lonchamp	France	Record high maximum temperature	30.8 C (87.4 F)	30 of 100 (Routine)
Guayama 1SW	Puerto Rico [United States]	Record low maximum temperature	25.6 C (78.1 F)	30 of 100 (Routine)
Masindi	Uganda	Record daily precipitation	36.7 mm (1.4 in)	30 of 100 (Routine)
Wandering Comparison	Australia	Record low minimum temperature	-1.5 C (29.3 F)	29 of 100 (Routine)
Saude	Brazil	Record daily precipitation	25.2 mm (1.0 in)	29 of 100 (Routine)

Counts by Type and Timescale

478 records

Records set or tied on 17 September 1975 by type: Highest daily maximum 55, Lowest daily maximum 58, Highest daily minimum 122, Lowest daily minimum 34, Heaviest daily rainfall 209.

Records on 17 September 1975 by type
Record type	Records
Highest daily maximum	55
Lowest daily maximum	58
Highest daily minimum	122
Lowest daily minimum	34
Heaviest daily rainfall	209
Heaviest daily snowfall	0
Deepest snow cover	0

Records on 17 September 1975 by timescale: all-time 4, monthly 19, daily 455.

How Much Records Were Beaten By

406 broken records

Margins by which the 406 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 135.6. Ties are not counted.

Top 20 by Significance

17 September 1975

Top 20 records on 17 September 1975 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
17 September 1975	Lajas Substn, PR	all-time rain	311.4 mm (12.3 in)	128.5 mm (5.1 in)	11 years	70 of 100 (Major)
17 September 1975	Arecibo 3 ESE, PR	all-time rain	228.6 mm (9.0 in)	67.3 mm (2.6 in)	6 years	66 of 100 (Major)
17 September 1975	Isabela Substn, PR	daily rain	123.7 mm (4.9 in)	70.4 mm (2.8 in)	64 years	66 of 100 (Major)
17 September 1975	Eberys, AU	daily rain	54.2 mm (2.1 in)	31.8 mm (1.3 in)	41 years	58 of 100 (Notable)
17 September 1975	Juana Diaz Camp, PR	daily rain	191.5 mm (7.5 in)	135.6 mm (5.3 in)	34 years	54 of 100 (Notable)
17 September 1975	Moosomin, CA	daily rain	34.5 mm (1.4 in)	25.4 mm (1.0 in)	69 years	53 of 100 (Notable)
17 September 1975	Boissevain, CA	daily rain	28.4 mm (1.1 in)	22.8 mm (0.9 in)	44 years	51 of 100 (Notable)
17 September 1975	Mayaguez City, PR	daily rain	170.2 mm (6.7 in)	105.2 mm (4.1 in)	8 years	49 of 100 (Notable)
17 September 1975	Cartwright, CA	daily rain	29.2 mm (1.1 in)	21.3 mm (0.8 in)	69 years	48 of 100 (Notable)
17 September 1975	Ninette, CA	daily rain	44.7 mm (1.8 in)	18.5 mm (0.7 in)	53 years	48 of 100 (Notable)
17 September 1975	Hohenpeissenberg, DE	monthly high min	21.2 C (70.2 F)	1.8 C (3.2 F)	80 years	47 of 100 (Notable)
17 September 1975	Pierson, CA	daily rain	27.9 mm (1.1 in)	19.0 mm (0.7 in)	53 years	46 of 100 (Notable)
17 September 1975	Garzas, PR	daily rain	174.0 mm (6.9 in)	129.0 mm (5.1 in)	12 years	46 of 100 (Notable)
17 September 1975	Borinquen AP, PR	daily rain	86.4 mm (3.4 in)	56.9 mm (2.2 in)	12 years	46 of 100 (Notable)
17 September 1975	Humacao 2 SSE, PR	daily rain	132.6 mm (5.2 in)	83.6 mm (3.3 in)	4 years	45 of 100 (Notable)
17 September 1975	Juncos 1 SE, PR	daily rain	91.2 mm (3.6 in)	60.7 mm (2.4 in)	22 years	45 of 100 (Notable)
17 September 1975	Saentis, CH	monthly high max	17.0 C (62.6 F)	0.1 C (0.2 F)	89 years	45 of 100 (Notable)
17 September 1975	Ruy Barbosa, BR	daily rain	35.0 mm (1.4 in)	23.7 mm (0.9 in)	1 year	44 of 100 (Notable)
17 September 1975	Indian Head Cda, CA	daily rain	30.0 mm (1.2 in)	17.3 mm (0.7 in)	56 years	44 of 100 (Notable)
17 September 1975	Russell, CA	daily rain	34.3 mm (1.4 in)	18.6 mm (0.7 in)	29 years	44 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

1796 to 1975

Records set or tied on this calendar date in each year from 1796 to 1975. 1975 had 478 records.

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

Records on 09-17 in each year
Year	Records
1796	1
1797	1
1805	1
1833	1
1834	1
1837	2
1845	1
1847	3
1848	1
1850	1
1851	2
1853	2
1854	2
1859	1
1862	1
1867	1
1870	1
1871	1
1872	1
1873	1
1874	1
1875	1
1877	1
1881	1
1882	2
1884	3
1885	3
1886	6
1888	2
1889	8
1891	1
1893	3
1894	1
1895	4
1896	9
1897	4
1898	7
1899	1
1900	4
1901	5
1902	5
1903	28
1904	2
1905	17
1906	10
1907	15
1908	13
1909	7
1910	38
1911	15
1912	17
1913	28
1914	38
1915	48
1916	40
1917	255
1918	41
1919	21
1920	40
1921	66
1922	47
1923	159
1924	80
1925	338
1926	154
1927	420
1928	78
1929	168
1930	147
1931	564
1932	425
1933	415
1934	246
1935	321
1936	219
1937	463
1938	363
1939	294
1940	326
1941	328
1942	581
1943	513
1944	403
1945	614
1946	620
1947	680
1948	630
1949	292
1950	412
1951	359
1952	263
1953	344
1954	449
1955	649
1956	437
1957	405
1958	806
1959	1,210
1960	385
1961	657
1962	432
1963	297
1964	559
1965	1,394
1966	523
1967	331
1968	691
1969	352
1970	412
1971	898
1972	556
1973	638
1974	491
1975	478
1976	636
1977	641
1978	764
1979	804
1980	794
1981	1,155
1982	606
1983	862
1984	1,006
1985	448
1986	1,314
1987	926
1988	982
1989	863
1990	650
1991	1,407
1992	686
1993	950
1994	986
1995	1,145
1996	1,342
1997	1,057
1998	1,137
1999	1,102
2000	1,318
2001	895
2002	1,025
2003	586
2004	872
2005	1,042
2006	1,344
2007	752
2008	886
2009	871
2010	907
2011	1,116
2012	597
2013	1,253
2014	571
2015	953
2016	707
2017	455
2018	899
2019	774
2020	651
2021	345
2022	313
2023	646
2024	954
2025	634
2026	968

Download the Data

Data for records on 1975-09-17: 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 2026-10-16. Last revised 16 October 2026 (2026-10-16).

Margin	Records
0 to 20	380
20 to 40	15
40 to 60	2
60 to 80	4
80 to 100	1
100 to 120	1
120 to 140	3