Weather Records on 18 August 2009

839 weather records were set or tied worldwide on 18 August 2009. Highest significance: Brunswick, US.

Key Facts for 18 August 2009

On 18 August 2009, 839 weather records were set or tied at long-record stations worldwide.
408 were record highs and 259 were record lows, counting maximum and minimum temperature.
By timescale, 4 were all-time records, 27 monthly and 808 daily.
Brunswick set a daily record precipitation of 98.8 mm (3.9 in) on 18 August 2009.
Across 171 earlier years (1797 to 2026) the same calendar date averaged 439 records.

Record Map

839 stations

839 station records on 18 August 2009 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 18 August 2009: highest significance records shown on the map
Station	Country	Type	Value	Significance
Brunswick	United States	Record daily precipitation	98.8 mm (3.9 in)	65 of 100 (Major)
Paulding	United States	Record daily precipitation	74.7 mm (2.9 in)	63 of 100 (Major)
Webster	United States	Record daily precipitation	111.8 mm (4.4 in)	62 of 100 (Major)
Tancochapa	Mexico	Record daily precipitation	134.9 mm (5.3 in)	57 of 100 (Notable)
Weatherford	United States	Record daily precipitation	88.9 mm (3.5 in)	55 of 100 (Notable)
Actopan	Mexico	Record low maximum temperature	24.4 C (75.9 F)	53 of 100 (Notable)
Warsaw	United States	Record daily precipitation	110.0 mm (4.3 in)	52 of 100 (Notable)
Presa la Calera	Mexico	Record low minimum temperature	15.6 C (60.1 F)	51 of 100 (Notable)
Jefferson 3SE	United States	Record daily precipitation	152.4 mm (6.0 in)	51 of 100 (Notable)
Oahe Dam	United States	Record daily precipitation	47.0 mm (1.9 in)	51 of 100 (Notable)
Great Bend 3WNW	United States	Record daily precipitation	52.1 mm (2.1 in)	50 of 100 (Notable)
Blackwell 1SSW	United States	Record daily precipitation	174.0 mm (6.9 in)	50 of 100 (Notable)
Ponca City	United States	Record daily precipitation	100.3 mm (3.9 in)	48 of 100 (Notable)
Yanzhou	China	Record daily precipitation	113.3 mm (4.5 in)	46 of 100 (Notable)
Azueta	Mexico	Record low maximum temperature	23.9 C (75.0 F)	46 of 100 (Notable)
Jerseyville 2 SW	United States	Record daily precipitation	59.2 mm (2.3 in)	46 of 100 (Notable)
Caldwell	United States	Record daily precipitation	105.4 mm (4.1 in)	46 of 100 (Notable)
Santiago Choapan	Mexico	Record daily precipitation	170.9 mm (6.7 in)	45 of 100 (Notable)
Guthrie 5S	United States	Record daily precipitation	64.0 mm (2.5 in)	45 of 100 (Notable)
Watonga	United States	Record daily precipitation	84.6 mm (3.3 in)	45 of 100 (Notable)
Evergreen	United States	Record low maximum temperature	25.6 C (78.1 F)	44 of 100 (Notable)
Zapote	Mexico	Record low maximum temperature	25.0 C (77.0 F)	43 of 100 (Notable)
W Lafayette 6 NW	United States	Record daily precipitation	65.0 mm (2.6 in)	43 of 100 (Notable)
Billings	United States	Record daily precipitation	73.7 mm (2.9 in)	43 of 100 (Notable)
Canton	Mexico	Record daily precipitation	130.3 mm (5.1 in)	42 of 100 (Notable)
Selma	United States	Record low maximum temperature	26.7 C (80.1 F)	42 of 100 (Notable)
Donnybrook	Australia	Record high minimum temperature	14.4 C (57.9 F)	41 of 100 (Notable)
Ciudad Aleman	Mexico	Record low maximum temperature	26.1 C (79.0 F)	41 of 100 (Notable)
Tuba City	United States	Record low minimum temperature	8.3 C (46.9 F)	41 of 100 (Notable)
Calhoun City	United States	Record low maximum temperature	27.8 C (82.0 F)	41 of 100 (Notable)
Turgaj	Kazakhstan	Record low maximum temperature	17.6 C (63.7 F)	40 of 100 (Notable)
Jose Cardel	Mexico	Record low maximum temperature	25.0 C (77.0 F)	40 of 100 (Notable)
Norrby_S	Sweden	Record daily precipitation	28.4 mm (1.1 in)	40 of 100 (Notable)
Karesuando	Sweden	Record low minimum temperature	-0.7 C (30.7 F)	40 of 100 (Notable)
Trinidad	United States	Record low minimum temperature	3.3 C (37.9 F)	40 of 100 (Notable)
Niceville	United States	Record low maximum temperature	25.6 C (78.1 F)	40 of 100 (Notable)
Ellsworth	United States	Record low maximum temperature	23.3 C (73.9 F)	40 of 100 (Notable)
Leavenworth	United States	Record daily precipitation	68.6 mm (2.7 in)	40 of 100 (Notable)
Newton	United States	Record daily precipitation	35.8 mm (1.4 in)	40 of 100 (Notable)
Sandusky	United States	Record high minimum temperature	21.1 C (70.0 F)	40 of 100 (Notable)
Wheeler	United States	Record daily precipitation	48.3 mm (1.9 in)	40 of 100 (Notable)
Jesus Carranza	Mexico	Record low maximum temperature	25.0 C (77.0 F)	39 of 100 (Notable)
Nyssa	United States	Record low minimum temperature	2.8 C (37.0 F)	39 of 100 (Notable)
Apuka	Russia	Record high maximum temperature	21.3 C (70.3 F)	38 of 100 (Notable)
Del Norte 3ENE	United States	Record low minimum temperature	2.2 C (36.0 F)	38 of 100 (Notable)
Daytona Beach	United States	Record high minimum temperature	27.8 C (82.0 F)	38 of 100 (Notable)
Melbourne WFO	United States	Record high minimum temperature	27.2 C (81.0 F)	38 of 100 (Notable)
Fall Rvr Lake	United States	Record daily precipitation	65.0 mm (2.6 in)	38 of 100 (Notable)
Howard 2SE	United States	Record daily precipitation	70.1 mm (2.8 in)	38 of 100 (Notable)
Lincoln 1 SE	United States	Record low maximum temperature	23.9 C (75.0 F)	38 of 100 (Notable)
Norwich	United States	Record low maximum temperature	25.0 C (77.0 F)	38 of 100 (Notable)
Kingfisher	United States	Record daily precipitation	45.7 mm (1.8 in)	38 of 100 (Notable)
Dinosaur Nm-Quarry Area	United States	Record low minimum temperature	-0.6 C (30.9 F)	38 of 100 (Notable)
Greenville	United States	Record low maximum temperature	26.7 C (80.1 F)	37 of 100 (Notable)
Hudson	United States	Record daily precipitation	47.0 mm (1.9 in)	37 of 100 (Notable)
Defiance	United States	Record daily precipitation	76.7 mm (3.0 in)	37 of 100 (Notable)
Newkirk 5NE	United States	Record daily precipitation	85.1 mm (3.4 in)	37 of 100 (Notable)
Brewton 3 SSE	United States	Record low maximum temperature	26.7 C (80.1 F)	36 of 100 (Notable)
Aberdeen	United States	Record low maximum temperature	27.2 C (81.0 F)	36 of 100 (Notable)
Mazamitla	Mexico	Record daily precipitation	63.0 mm (2.5 in)	35 of 100 (Notable)

Counts by Type and Timescale

839 records

Records set or tied on 18 August 2009 by type: Highest daily maximum 206, Lowest daily maximum 144, Highest daily minimum 202, Lowest daily minimum 115, Heaviest daily rainfall 172.

Records on 18 August 2009 by type
Record type	Records
Highest daily maximum	206
Lowest daily maximum	144
Highest daily minimum	202
Lowest daily minimum	115
Heaviest daily rainfall	172
Heaviest daily snowfall	0
Deepest snow cover	0

Records on 18 August 2009 by timescale: all-time 4, monthly 27, daily 808.

How Much Records Were Beaten By

570 broken records

Margins by which the 570 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 101.6. Ties are not counted.

Top 20 by Significance

18 August 2009

Top 20 records on 18 August 2009 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
18 August 2009	Brunswick, US	daily rain	98.8 mm (3.9 in)	39.4 mm (1.6 in)	94 years	65 of 100 (Major)
18 August 2009	Paulding, US	daily rain	74.7 mm (2.9 in)	40.9 mm (1.6 in)	55 years	63 of 100 (Major)
18 August 2009	Webster, US	monthly rain	111.8 mm (4.4 in)	33.6 mm (1.3 in)	53 years	62 of 100 (Major)
18 August 2009	Tancochapa, MX	daily rain	134.9 mm (5.3 in)	101.6 mm (4.0 in)	38 years	57 of 100 (Notable)
18 August 2009	Weatherford, US	daily rain	88.9 mm (3.5 in)	26.7 mm (1.1 in)	99 years	55 of 100 (Notable)
18 August 2009	Actopan, MX	daily low max	24.4 C (75.9 F)	6.2 C (11.2 F)	48 years	53 of 100 (Notable)
18 August 2009	Warsaw, US	daily rain	110.0 mm (4.3 in)	66.8 mm (2.6 in)	8 years	52 of 100 (Notable)
18 August 2009	Presa la Calera, MX	daily low min	15.6 C (60.1 F)	4.4 C (7.9 F)	32 years	51 of 100 (Notable)
18 August 2009	Jefferson 3SE, US	monthly rain	152.4 mm (6.0 in)	3.0 mm (0.12 in)	111 years	51 of 100 (Notable)
18 August 2009	Oahe Dam, US	daily rain	47.0 mm (1.9 in)	31.8 mm (1.3 in)	38 years	51 of 100 (Notable)
18 August 2009	Great Bend 3WNW, US	daily rain	52.1 mm (2.1 in)	32.5 mm (1.3 in)	68 years	50 of 100 (Notable)
18 August 2009	Blackwell 1SSW, US	all-time rain	174.0 mm (6.9 in)	18.8 mm (0.7 in)	47 years	50 of 100 (Notable)
18 August 2009	Ponca City, US	monthly rain	100.3 mm (3.9 in)	13.9 mm (0.5 in)	67 years	48 of 100 (Notable)
18 August 2009	Yanzhou, CN	daily rain	113.3 mm (4.5 in)	64.8 mm (2.6 in)	44 years	46 of 100 (Notable)
18 August 2009	Azueta, MX	daily low max	23.9 C (75.0 F)	5.5 C (9.9 F)	48 years	46 of 100 (Notable)
18 August 2009	Jerseyville 2 SW, US	daily rain	59.2 mm (2.3 in)	40.9 mm (1.6 in)	44 years	46 of 100 (Notable)
18 August 2009	Caldwell, US	monthly rain	105.4 mm (4.1 in)	26.7 mm (1.1 in)	40 years	46 of 100 (Notable)
18 August 2009	Santiago Choapan, MX	monthly rain	170.9 mm (6.7 in)	49.5 mm (1.9 in)	25 years	45 of 100 (Notable)
18 August 2009	Guthrie 5S, US	daily rain	64.0 mm (2.5 in)	38.3 mm (1.5 in)	44 years	45 of 100 (Notable)
18 August 2009	Watonga, US	daily rain	84.6 mm (3.3 in)	38.4 mm (1.5 in)	48 years	45 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

1797 to 2009

Records set or tied on this calendar date in each year from 1797 to 2009. 2009 had 839 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 2009-08-18: 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	530
20 to 40	31
40 to 60	5
60 to 80	3
80 to 100	0
100 to 120	1