Weather Records on 21 September 2017

1,178 weather records were set or tied worldwide on 21 September 2017. Highest significance: Williams, AU.

Key Facts for 21 September 2017

On 21 September 2017, 1,178 weather records were set or tied at long-record stations worldwide.
654 were record highs and 296 were record lows, counting maximum and minimum temperature.
By timescale, 3 were all-time records, 33 monthly and 1,142 daily.
Williams set a daily record precipitation of 35.2 mm (1.4 in) on 21 September 2017.
Across 155 earlier years (1805 to 2026) the same calendar date averaged 446 records.

Record Map

1,178 stations

1,178 station records on 21 September 2017 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 21 September 2017: highest significance records shown on the map
Station	Country	Type	Value	Significance
Williams	Australia	Record daily precipitation	35.2 mm (1.4 in)	76 of 100 (Major)
Chilton	United States	Record daily precipitation	90.2 mm (3.6 in)	71 of 100 (Major)
Maricao Fish Hatchery	Puerto Rico [United States]	Record daily precipitation	558.8 mm (22.0 in)	65 of 100 (Major)
Sagar	India	Record daily precipitation	132.1 mm (5.2 in)	64 of 100 (Major)
Fairfield	United States	Record daily precipitation	147.6 mm (5.8 in)	63 of 100 (Major)
Beowawe	United States	Record daily precipitation	28.2 mm (1.1 in)	55 of 100 (Notable)
Aberdeen Exp STN	United States	Record daily precipitation	25.9 mm (1.0 in)	53 of 100 (Notable)
Blackfoot Fire Dept	United States	Record daily precipitation	29.0 mm (1.1 in)	53 of 100 (Notable)
Ft Hall 1 NNE	United States	Record daily precipitation	25.7 mm (1.0 in)	53 of 100 (Notable)
Fisher Creek	United States	Record daily precipitation	40.6 mm (1.6 in)	53 of 100 (Notable)
Ensenada 1 W	Puerto Rico [United States]	Record daily precipitation	236.2 mm (9.3 in)	51 of 100 (Notable)
Lajas Substn	Puerto Rico [United States]	Record daily precipitation	190.5 mm (7.5 in)	51 of 100 (Notable)
Brunswick Junction	Australia	Record daily precipitation	33.8 mm (1.3 in)	50 of 100 (Notable)
Greenville 2 NNE	United States	Record high maximum temperature	35.6 C (96.1 F)	49 of 100 (Notable)
Two Ocean Plateau	United States	Record daily precipitation	50.8 mm (2.0 in)	49 of 100 (Notable)
Marradong	Australia	Record daily precipitation	26.0 mm (1.0 in)	48 of 100 (Notable)
Penang Intl	Malaysia	Record daily precipitation	122.2 mm (4.8 in)	48 of 100 (Notable)
Crater Lake Nps HQ	United States	Record daily snowfall	17.8 cm (7.0 in)	47 of 100 (Notable)
White Mill	United States	Record daily precipitation	40.6 mm (1.6 in)	47 of 100 (Notable)
Box Canyon	United States	Record daily precipitation	27.9 mm (1.1 in)	46 of 100 (Notable)
Nantucket Mem AP	United States	Record daily precipitation	81.0 mm (3.2 in)	46 of 100 (Notable)
Wagerup Refinery	Australia	Record daily precipitation	58.0 mm (2.3 in)	45 of 100 (Notable)
Podor	Senegal	Record high maximum temperature	43.5 C (110.3 F)	45 of 100 (Notable)
Merced	United States	Record low maximum temperature	22.2 C (72.0 F)	45 of 100 (Notable)
Trang	Thailand	Record daily precipitation	118.9 mm (4.7 in)	44 of 100 (Notable)
Ft Hall 1 NNE	United States	Record low maximum temperature	6.7 C (44.1 F)	44 of 100 (Notable)
Oshkosh	United States	Record daily precipitation	61.7 mm (2.4 in)	44 of 100 (Notable)
Galesburg	United States	Record high maximum temperature	33.3 C (91.9 F)	42 of 100 (Notable)
Brighton	United States	Record daily precipitation	58.4 mm (2.3 in)	42 of 100 (Notable)
Maquoketa	United States	Record high maximum temperature	33.3 C (91.9 F)	42 of 100 (Notable)
Charlevoix	United States	Record high maximum temperature	28.9 C (84.0 F)	42 of 100 (Notable)
Unionville	United States	Record high minimum temperature	20.6 C (69.1 F)	42 of 100 (Notable)
Falls City 2 SSW	United States	Record low maximum temperature	12.2 C (54.0 F)	42 of 100 (Notable)
Heppner	United States	Record low maximum temperature	12.2 C (54.0 F)	42 of 100 (Notable)
Wilbur	United States	Record low maximum temperature	10.6 C (51.1 F)	42 of 100 (Notable)
Darlington Wwtp	United States	Record high maximum temperature	32.2 C (90.0 F)	42 of 100 (Notable)
Walnut	United States	Record high maximum temperature	33.9 C (93.0 F)	41 of 100 (Notable)
Allerton	United States	Record high minimum temperature	20.6 C (69.1 F)	41 of 100 (Notable)
Montague 4 NW	United States	Record high maximum temperature	30.6 C (87.1 F)	41 of 100 (Notable)
Ewing	United States	Record high minimum temperature	23.3 C (73.9 F)	41 of 100 (Notable)
Greenville Kgvl Radio	United States	Record high minimum temperature	26.1 C (79.0 F)	41 of 100 (Notable)
Lake Mills Wwtp	United States	Record high maximum temperature	33.9 C (93.0 F)	41 of 100 (Notable)
Reedsburg Wwtp	United States	Record high maximum temperature	30.6 C (87.1 F)	41 of 100 (Notable)
Big Creek Sum	United States	Record daily precipitation	25.4 mm (1.0 in)	41 of 100 (Notable)
Kursk	Russia	Record high maximum temperature	26.5 C (79.7 F)	40 of 100 (Notable)
Tak	Thailand	Record daily precipitation	112.0 mm (4.4 in)	40 of 100 (Notable)
Keosauqua	United States	Record high maximum temperature	34.4 C (93.9 F)	40 of 100 (Notable)
Adel	United States	Record low maximum temperature	9.4 C (48.9 F)	40 of 100 (Notable)
Antlers	United States	Record high minimum temperature	23.9 C (75.0 F)	40 of 100 (Notable)
Bonham 3NNE	United States	Record high minimum temperature	25.0 C (77.0 F)	40 of 100 (Notable)
Dwellingup	Australia	Record daily precipitation	42.0 mm (1.7 in)	39 of 100 (Notable)
Majuro Wbas AP	Marshall Islands	Record daily precipitation	91.9 mm (3.6 in)	39 of 100 (Notable)
Elgin Water	United States	Record high maximum temperature	32.2 C (90.0 F)	39 of 100 (Notable)
Cedar Rapids #1	United States	Record high maximum temperature	34.4 C (93.9 F)	39 of 100 (Notable)
Fallon Exp STN	United States	Record low maximum temperature	13.3 C (55.9 F)	39 of 100 (Notable)
Weatherford	United States	Record high minimum temperature	23.9 C (75.0 F)	39 of 100 (Notable)
Wills Pt	United States	Record high minimum temperature	24.4 C (75.9 F)	39 of 100 (Notable)
Goldendale	United States	Record low maximum temperature	12.8 C (55.0 F)	39 of 100 (Notable)
Alta 1 NNW	United States	Record daily precipitation	28.7 mm (1.1 in)	39 of 100 (Notable)
Parker Peak	United States	Record daily precipitation	35.6 mm (1.4 in)	39 of 100 (Notable)

Counts by Type and Timescale

1,178 records

Records set or tied on 21 September 2017 by type: Highest daily maximum 290, Lowest daily maximum 257, Highest daily minimum 364, Lowest daily minimum 39, Heaviest daily rainfall 216, Heaviest daily snowfall 6, Deepest snow cover 6.

Records on 21 September 2017 by type
Record type	Records
Highest daily maximum	290
Lowest daily maximum	257
Highest daily minimum	364
Lowest daily minimum	39
Heaviest daily rainfall	216
Heaviest daily snowfall	6
Deepest snow cover	6

Records on 21 September 2017 by timescale: all-time 3, monthly 33, daily 1,142.

How Much Records Were Beaten By

932 broken records

Margins by which the 932 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 171.4. Ties are not counted.

Top 20 by Significance

21 September 2017

Top 20 records on 21 September 2017 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
21 September 2017	Williams, AU	daily rain	35.2 mm (1.4 in)	22.5 mm (0.9 in)	88 years	76 of 100 (Major)
21 September 2017	Chilton, US	daily rain	90.2 mm (3.6 in)	51.1 mm (2.0 in)	70 years	71 of 100 (Major)
21 September 2017	Maricao Fish Hatchery, PR	all-time rain	558.8 mm (22.0 in)	100.3 mm (3.9 in)	18 years	65 of 100 (Major)
21 September 2017	Sagar, IN	daily rain	132.1 mm (5.2 in)	90.1 mm (3.5 in)	48 years	64 of 100 (Major)
21 September 2017	Fairfield, US	all-time rain	147.6 mm (5.8 in)	29.5 mm (1.2 in)	47 years	63 of 100 (Major)
21 September 2017	Beowawe, US	daily rain	28.2 mm (1.1 in)	23.1 mm (0.9 in)	19 years	55 of 100 (Notable)
21 September 2017	Aberdeen Exp STN, US	daily rain	25.9 mm (1.0 in)	13.2 mm (0.5 in)	48 years	53 of 100 (Notable)
21 September 2017	Blackfoot Fire Dept, US	daily rain	29.0 mm (1.1 in)	12.7 mm (0.5 in)	72 years	53 of 100 (Notable)
21 September 2017	Ft Hall 1 NNE, US	daily rain	25.7 mm (1.0 in)	11.7 mm (0.5 in)	72 years	53 of 100 (Notable)
21 September 2017	Fisher Creek, US	daily rain	40.6 mm (1.6 in)	25.4 mm (1.0 in)	32 years	53 of 100 (Notable)
21 September 2017	Ensenada 1 W, PR	daily rain	236.2 mm (9.3 in)	171.4 mm (6.7 in)	19 years	51 of 100 (Notable)
21 September 2017	Lajas Substn, PR	daily rain	190.5 mm (7.5 in)	48.3 mm (1.9 in)	68 years	51 of 100 (Notable)
21 September 2017	Brunswick Junction, AU	daily rain	33.8 mm (1.3 in)	11.4 mm (0.4 in)	87 years	50 of 100 (Notable)
21 September 2017	Greenville 2 NNE, US	daily high max	35.6 C (96.1 F)	4.5 C (8.1 F)	103 years	49 of 100 (Notable)
21 September 2017	Two Ocean Plateau, US	monthly rain	50.8 mm (2.0 in)	15.2 mm (0.6 in)	31 years	49 of 100 (Notable)
21 September 2017	Marradong, AU	daily rain	26.0 mm (1.0 in)	7.5 mm (0.30 in)	88 years	48 of 100 (Notable)
21 September 2017	Penang Intl, MY	daily rain	122.2 mm (4.8 in)	62.3 mm (2.5 in)	51 years	48 of 100 (Notable)
21 September 2017	Crater Lake Nps HQ, US	daily snowfall	17.8 cm (7.0 in)	17.0 cm (6.7 in)	56 years	47 of 100 (Notable)
21 September 2017	White Mill, US	monthly rain	40.6 mm (1.6 in)	12.7 mm (0.5 in)	24 years	47 of 100 (Notable)
21 September 2017	Box Canyon, US	daily rain	27.9 mm (1.1 in)	15.2 mm (0.6 in)	32 years	46 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

1805 to 2017

Records set or tied on this calendar date in each year from 1805 to 2017. 2017 had 1,178 records.

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

Records on 09-21 in each year
Year	Records
1805	1
1812	1
1825	2
1840	1
1841	1
1842	1
1848	1
1854	1
1856	2
1868	1
1872	2
1873	1
1877	1
1878	1
1881	1
1882	1
1884	1
1886	1
1888	2
1889	1
1891	10
1892	1
1893	10
1894	2
1895	3
1896	2
1897	6
1898	6
1899	3
1900	2
1901	5
1902	5
1903	8
1904	20
1905	12
1906	17
1907	10
1908	17
1909	10
1910	8
1911	18
1912	26
1913	37
1914	29
1915	34
1916	48
1917	28
1918	43
1919	54
1920	29
1921	64
1922	35
1923	232
1924	291
1925	278
1926	178
1927	165
1928	81
1929	232
1930	82
1931	681
1932	242
1933	193
1934	492
1935	199
1936	329
1937	487
1938	508
1939	308
1940	908
1941	416
1942	291
1943	407
1944	413
1945	507
1946	176
1947	534
1948	301
1949	298
1950	334
1951	241
1952	430
1953	382
1954	453
1955	752
1956	1,100
1957	366
1958	588
1959	513
1960	418
1961	441
1962	1,085
1963	306
1964	374
1965	1,088
1966	565
1967	577
1968	790
1969	593
1970	708
1971	645
1972	599
1973	421
1974	652
1975	528
1976	694
1977	918
1978	818
1979	736
1980	990
1981	696
1982	1,484
1983	2,207
1984	707
1985	796
1986	671
1987	965
1988	557
1989	1,002
1990	716
1991	1,021
1992	752
1993	911
1994	713
1995	2,002
1996	1,233
1997	1,112
1998	1,481
1999	1,025
2000	884
2001	718
2002	696
2003	959
2004	888
2005	1,143
2006	920
2007	742
2008	740
2009	715
2010	1,290
2011	542
2012	595
2013	769
2014	716
2015	565
2016	989
2017	1,178
2018	1,051
2019	833
2020	580
2021	465
2022	1,049
2023	783
2024	470
2025	588
2026	469

Download the Data

Data for records on 2017-09-21: 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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-13. Last revised 13 October 2026 (2026-10-13).

Margin	Records
0 to 25	908
25 to 50	15
50 to 75	4
75 to 100	2
100 to 125	1
125 to 150	0
150 to 175	2