Weather Records on 18 August 1991

533 weather records were set or tied worldwide on 18 August 1991. Highest significance: Springfield 2W, US.

Key Facts for 18 August 1991

On 18 August 1991, 533 weather records were set or tied at long-record stations worldwide.
267 were record highs and 88 were record lows, counting maximum and minimum temperature.
By timescale, 1 were all-time records, 17 monthly and 515 daily.
Springfield 2W set a daily record precipitation of 69.3 mm (2.7 in) on 18 August 1991.
Across 171 earlier years (1797 to 2026) the same calendar date averaged 440 records.

Record Map

533 stations

533 station records on 18 August 1991 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 18 August 1991: highest significance records shown on the map
Station	Country	Type	Value	Significance
Springfield 2W	United States	Record daily precipitation	69.3 mm (2.7 in)	57 of 100 (Notable)
Cape Hatteras - Billy Mitchell	United States	Record daily precipitation	134.6 mm (5.3 in)	49 of 100 (Notable)
Hillsboro	United States	Record daily precipitation	64.0 mm (2.5 in)	47 of 100 (Notable)
Merida Centro	Mexico	Record low maximum temperature	25.0 C (77.0 F)	43 of 100 (Notable)
W Plains	United States	Record daily precipitation	76.7 mm (3.0 in)	43 of 100 (Notable)
New Albany	United States	Record daily precipitation	48.3 mm (1.9 in)	42 of 100 (Notable)
Piketon	United States	Record daily precipitation	53.3 mm (2.1 in)	41 of 100 (Notable)
Ratcliff	United States	Record daily precipitation	53.3 mm (2.1 in)	39 of 100 (Notable)
Knightstown 2 ENE	United States	Record daily precipitation	42.9 mm (1.7 in)	39 of 100 (Notable)
Porvoo Jernbole	Finland	Record daily precipitation	59.5 mm (2.3 in)	38 of 100 (Notable)
Stratford	United States	Record daily precipitation	53.3 mm (2.1 in)	38 of 100 (Notable)
Fredericksburg Np	United States	Record high minimum temperature	24.4 C (75.9 F)	38 of 100 (Notable)
Maceio (Aeroporto)	Brazil	Record daily precipitation	66.0 mm (2.6 in)	36 of 100 (Notable)
Mkambati	South Africa	Record daily precipitation	53.9 mm (2.1 in)	36 of 100 (Notable)
McKenzie Rvr Rs	United States	Record daily precipitation	36.3 mm (1.4 in)	36 of 100 (Notable)
Seymour 1 WSW	United States	Record daily precipitation	32.0 mm (1.3 in)	35 of 100 (Notable)
Walterboro 1 SW	United States	Record high minimum temperature	25.6 C (78.1 F)	35 of 100 (Notable)
Mixquiahuala (Smn)	Mexico	Record daily precipitation	31.0 mm (1.2 in)	34 of 100 (Routine)
Soledad de Doblado	Mexico	Record high maximum temperature	42.8 C (109.0 F)	34 of 100 (Routine)
Manorkill	United States	Record daily precipitation	48.8 mm (1.9 in)	34 of 100 (Routine)
Paso de San Antonio	Mexico	Record daily precipitation	190.0 mm (7.5 in)	33 of 100 (Routine)
Faywood	United States	Record daily precipitation	40.6 mm (1.6 in)	33 of 100 (Routine)
Helsinki-Malmin Lentoasema	Finland	Record daily precipitation	37.7 mm (1.5 in)	32 of 100 (Routine)
San Lucas Ojitlan	Mexico	Record low minimum temperature	17.8 C (64.0 F)	32 of 100 (Routine)
Sakon Nakhon	Thailand	Record daily precipitation	132.1 mm (5.2 in)	32 of 100 (Routine)
Khon Kaen	Thailand	Record daily precipitation	72.9 mm (2.9 in)	32 of 100 (Routine)
Oyameles	Mexico	Record daily precipitation	35.8 mm (1.4 in)	31 of 100 (Routine)
Dzitas	Mexico	Record high minimum temperature	26.7 C (80.1 F)	31 of 100 (Routine)
Gunib	Russia	Record daily precipitation	41.1 mm (1.6 in)	31 of 100 (Routine)
Alingsas_D	Sweden	Record daily precipitation	42.9 mm (1.7 in)	31 of 100 (Routine)
Nimrod Dam	United States	Record daily precipitation	54.9 mm (2.2 in)	31 of 100 (Routine)
Wauchula	United States	Record high minimum temperature	25.0 C (77.0 F)	31 of 100 (Routine)
Teocelo	Mexico	Record high maximum temperature	30.6 C (87.1 F)	30 of 100 (Routine)
Saint Maries	United States	Record high minimum temperature	17.2 C (63.0 F)	30 of 100 (Routine)
Mt Wx	United States	Record high minimum temperature	21.7 C (71.1 F)	30 of 100 (Routine)
Oujda	Morocco	Record high maximum temperature	40.5 C (104.9 F)	29 of 100 (Routine)
San Diego de Alejandria	Mexico	Record high maximum temperature	35.0 C (95.0 F)	29 of 100 (Routine)
Hatch	United States	Record daily precipitation	43.2 mm (1.7 in)	29 of 100 (Routine)
Palmerton	United States	Record high maximum temperature	33.9 C (93.0 F)	28 of 100 (Routine)
El Salto	Mexico	Record daily precipitation	44.7 mm (1.8 in)	27 of 100 (Routine)
Danville	United States	Record daily precipitation	32.5 mm (1.3 in)	27 of 100 (Routine)
Ordway 4 W	United States	Record daily precipitation	25.9 mm (1.0 in)	27 of 100 (Routine)
Pleasant Hill	United States	Record daily precipitation	35.6 mm (1.4 in)	27 of 100 (Routine)
Benxi	China	Record daily precipitation	83.0 mm (3.3 in)	26 of 100 (Routine)
Nakhon Sawan	Thailand	Record low maximum temperature	27.4 C (81.3 F)	26 of 100 (Routine)
Columbus	United States	Record daily precipitation	34.0 mm (1.3 in)	26 of 100 (Routine)
Lagodehi	Georgia	Record daily precipitation	33.9 mm (1.3 in)	25 of 100 (Routine)
Monclova (Dge)	Mexico	Record low maximum temperature	20.6 C (69.1 F)	25 of 100 (Routine)
Sihccajavri	Norway	Record daily precipitation	25.1 mm (1.0 in)	25 of 100 (Routine)
Chazy	United States	Record high minimum temperature	20.6 C (69.1 F)	25 of 100 (Routine)
Morrisville 6 SW	United States	Record high minimum temperature	19.4 C (66.9 F)	25 of 100 (Routine)
Espoo Kauklahti	Finland	Record daily precipitation	38.8 mm (1.5 in)	24 of 100 (Routine)
Inari Ivalo Lentoasema	Finland	Record daily precipitation	50.2 mm (2.0 in)	24 of 100 (Routine)
Inari Toivoniemi	Finland	Record daily precipitation	26.5 mm (1.0 in)	24 of 100 (Routine)
Huatusco de Chicuellar	Mexico	Record high maximum temperature	31.7 C (89.1 F)	24 of 100 (Routine)
Choshi	Japan	Record low maximum temperature	23.9 C (75.0 F)	23 of 100 (Routine)
Santiago	Mexico	Record high minimum temperature	26.7 C (80.1 F)	23 of 100 (Routine)
Ingenio Catmis	Mexico	Record high minimum temperature	23.9 C (75.0 F)	23 of 100 (Routine)
Steinhatchee 6 ENE	United States	Record high minimum temperature	26.1 C (79.0 F)	23 of 100 (Routine)
Eaton Rapids	United States	Record daily precipitation	41.1 mm (1.6 in)	23 of 100 (Routine)

Counts by Type and Timescale

533 records

Records set or tied on 18 August 1991 by type: Highest daily maximum 114, Lowest daily maximum 40, Highest daily minimum 153, Lowest daily minimum 48, Heaviest daily rainfall 178.

Records on 18 August 1991 by type
Record type	Records
Highest daily maximum	114
Lowest daily maximum	40
Highest daily minimum	153
Lowest daily minimum	48
Heaviest daily rainfall	178
Heaviest daily snowfall	0
Deepest snow cover	0

Records on 18 August 1991 by timescale: all-time 1, monthly 17, daily 515.

How Much Records Were Beaten By

374 broken records

Margins by which the 374 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 83.5. Ties are not counted.

Top 20 by Significance

18 August 1991

Top 20 records on 18 August 1991 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
18 August 1991	Springfield 2W, US	daily rain	69.3 mm (2.7 in)	48.0 mm (1.9 in)	44 years	57 of 100 (Notable)
18 August 1991	Cape Hatteras - Billy Mitchell, US	daily rain	134.6 mm (5.3 in)	83.5 mm (3.3 in)	20 years	49 of 100 (Notable)
18 August 1991	Hillsboro, US	monthly rain	64.0 mm (2.5 in)	8.1 mm (0.32 in)	65 years	47 of 100 (Notable)
18 August 1991	Merida Centro, MX	monthly low max	25.0 C (77.0 F)	3.9 C (7.0 F)	25 years	43 of 100 (Notable)
18 August 1991	W Plains, US	daily rain	76.7 mm (3.0 in)	51.0 mm (2.0 in)	30 years	43 of 100 (Notable)
18 August 1991	New Albany, US	daily rain	48.3 mm (1.9 in)	15.0 mm (0.6 in)	80 years	42 of 100 (Notable)
18 August 1991	Piketon, US	daily rain	53.3 mm (2.1 in)	25.6 mm (1.0 in)	46 years	41 of 100 (Notable)
18 August 1991	Ratcliff, US	daily rain	53.3 mm (2.1 in)	42.9 mm (1.7 in)	30 years	39 of 100 (Notable)
18 August 1991	Knightstown 2 ENE, US	daily rain	42.9 mm (1.7 in)	25.4 mm (1.0 in)	42 years	39 of 100 (Notable)
18 August 1991	Porvoo Jernbole, FI	all-time rain	59.5 mm (2.3 in)	4.5 mm (0.18 in)	31 years	38 of 100 (Notable)
18 August 1991	Stratford, US	daily rain	53.3 mm (2.1 in)	34.2 mm (1.3 in)	9 years	38 of 100 (Notable)
18 August 1991	Fredericksburg Np, US	daily high min	24.4 C (75.9 F)	1.1 C (2.0 F)	89 years	38 of 100 (Notable)
18 August 1991	Maceio (Aeroporto), BR	daily rain	66.0 mm (2.6 in)	6.2 mm (0.24 in)	76 years	36 of 100 (Notable)
18 August 1991	Mkambati, ZA	daily rain	53.9 mm (2.1 in)	41.4 mm (1.6 in)	24 years	36 of 100 (Notable)
18 August 1991	McKenzie Rvr Rs, US	daily rain	36.3 mm (1.4 in)	15.5 mm (0.6 in)	22 years	36 of 100 (Notable)
18 August 1991	Seymour 1 WSW, US	daily rain	32.0 mm (1.3 in)	3.6 mm (0.14 in)	80 years	35 of 100 (Notable)
18 August 1991	Walterboro 1 SW, US	daily high min	25.6 C (78.1 F)	0.6 C (1.1 F)	81 years	35 of 100 (Notable)
18 August 1991	Mixquiahuala (Smn), MX	daily rain	31.0 mm (1.2 in)	19.1 mm (0.8 in)	36 years	34 of 100 (Routine)
18 August 1991	Soledad de Doblado, MX	monthly high max	42.8 C (109.0 F)	2.2 C (4.0 F)	39 years	34 of 100 (Routine)
18 August 1991	Manorkill, US	daily rain	48.8 mm (1.9 in)	32.8 mm (1.3 in)	16 years	34 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 1991

Records set or tied on this calendar date in each year from 1797 to 1991. 1991 had 533 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 1991-08-18: 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 2026-10-16. Last revised 16 October 2026 (2026-10-16).

Margin	Records
0 to 20	355
20 to 40	12
40 to 60	6
60 to 80	0
80 to 100	1