Weather Records on 17 August 1978

814 weather records were set or tied worldwide on 17 August 1978. Highest significance: Lajas Substn, PR.

Key Facts for 17 August 1978

On 17 August 1978, 814 weather records were set or tied at long-record stations worldwide.
298 were record highs and 300 were record lows, counting maximum and minimum temperature.
By timescale, 7 were all-time records, 21 monthly and 786 daily.
Lajas Substn set a monthly record daily precipitation of 233.7 mm (9.2 in) on 17 August 1978.
Across 162 earlier years (1797 to 2026) the same calendar date averaged 472 records.

Record Map

814 stations

814 station records on 17 August 1978 are marked on the map, coloured by record type. Dot size shows the significance score. Made with Natural Earth.

Weather records on 17 August 1978: highest significance records shown on the map
Station	Country	Type	Value	Significance
Lajas Substn	Puerto Rico [United States]	Record daily precipitation	233.7 mm (9.2 in)	61 of 100 (Major)
Millstream	Australia	Record daily precipitation	58.2 mm (2.3 in)	53 of 100 (Notable)
Lethbridge A	Canada	Record daily precipitation	35.8 mm (1.4 in)	50 of 100 (Notable)
Mayaguez City	Puerto Rico [United States]	Record daily precipitation	81.3 mm (3.2 in)	46 of 100 (Notable)
Paauhau 217	United States	Record daily precipitation	82.6 mm (3.3 in)	43 of 100 (Notable)
Boaz	United States	Record daily precipitation	76.2 mm (3.0 in)	42 of 100 (Notable)
Dillon U of Montana Western	United States	Record low maximum temperature	13.3 C (55.9 F)	40 of 100 (Notable)
Ft Madison	United States	Record daily precipitation	43.2 mm (1.7 in)	39 of 100 (Notable)
Norris Madison Pwr House	United States	Record low maximum temperature	13.3 C (55.9 F)	39 of 100 (Notable)
Middletown 4 W	United States	Record high minimum temperature	23.9 C (75.0 F)	38 of 100 (Notable)
Virginia City	United States	Record low minimum temperature	-1.1 C (30.0 F)	38 of 100 (Notable)
Ny City Cntrl Park	United States	Record high minimum temperature	25.6 C (78.1 F)	38 of 100 (Notable)
Middleton	United States	Record high minimum temperature	25.0 C (77.0 F)	37 of 100 (Notable)
Bozeman Montana State UNIV	United States	Record low maximum temperature	12.2 C (54.0 F)	37 of 100 (Notable)
Alta 1 NNW	United States	Record low maximum temperature	12.8 C (55.0 F)	37 of 100 (Notable)
Butte Bert Mooney AP	United States	Record low maximum temperature	9.4 C (48.9 F)	37 of 100 (Notable)
Cambridge	United States	Record low minimum temperature	1.7 C (35.1 F)	36 of 100 (Notable)
Hobbs	United States	Record high minimum temperature	25.6 C (78.1 F)	36 of 100 (Notable)
Carmel	United States	Record high minimum temperature	22.8 C (73.0 F)	36 of 100 (Notable)
Kukuihaele Hic 199	United States	Record daily precipitation	97.8 mm (3.9 in)	36 of 100 (Notable)
Lewistown AP	United States	Record low maximum temperature	11.1 C (52.0 F)	36 of 100 (Notable)
Guayama 1SW	Puerto Rico [United States]	Record low maximum temperature	27.2 C (81.0 F)	35 of 100 (Notable)
Belle Glade	United States	Record daily precipitation	83.8 mm (3.3 in)	35 of 100 (Notable)
Saint Maries	United States	Record low maximum temperature	12.8 C (55.0 F)	35 of 100 (Notable)
Moorestown 4 E	United States	Record high maximum temperature	36.7 C (98.1 F)	35 of 100 (Notable)
Moran 5WNW	United States	Record low maximum temperature	11.1 C (52.0 F)	35 of 100 (Notable)
Lakeland Linder Rgnl AP	United States	Record daily precipitation	74.4 mm (2.9 in)	35 of 100 (Notable)
Hakea	Australia	Record daily precipitation	28.4 mm (1.1 in)	34 of 100 (Routine)
Island Falls	Canada	Record daily precipitation	32.2 mm (1.3 in)	34 of 100 (Routine)
Batamaj	Russia	Record daily precipitation	25.1 mm (1.0 in)	34 of 100 (Routine)
Merced	United States	Record low minimum temperature	5.6 C (42.1 F)	34 of 100 (Routine)
Elk City 1NE	United States	Record low maximum temperature	13.3 C (55.9 F)	34 of 100 (Routine)
Darby	United States	Record low maximum temperature	15.0 C (59.0 F)	34 of 100 (Routine)
Snowville	United States	Record low maximum temperature	21.7 C (71.1 F)	34 of 100 (Routine)
Oktjabrskij-Gorodok	Russia	Record low minimum temperature	3.3 C (37.9 F)	33 of 100 (Routine)
Hazelton	United States	Record low maximum temperature	17.2 C (63.0 F)	33 of 100 (Routine)
Riggins	United States	Record low maximum temperature	18.9 C (66.0 F)	33 of 100 (Routine)
Cascade 5 S	United States	Record low maximum temperature	12.8 C (55.0 F)	33 of 100 (Routine)
Wamsutter	United States	Record low minimum temperature	1.1 C (34.0 F)	33 of 100 (Routine)
Low Head (Comparison)	Australia	Record low minimum temperature	0.5 C (32.9 F)	32 of 100 (Routine)
Coloso	Puerto Rico [United States]	Record low maximum temperature	27.2 C (81.0 F)	32 of 100 (Routine)
Canon City	United States	Record low minimum temperature	7.8 C (46.0 F)	32 of 100 (Routine)
Malad	United States	Record low maximum temperature	18.3 C (64.9 F)	32 of 100 (Routine)
Payette	United States	Record low minimum temperature	3.9 C (39.0 F)	32 of 100 (Routine)
Frederick Police Brks	United States	Record high minimum temperature	22.8 C (73.0 F)	32 of 100 (Routine)
Plattsburgh AFB	United States	Record high minimum temperature	20.6 C (69.1 F)	32 of 100 (Routine)
Snowville	United States	Record low minimum temperature	1.1 C (34.0 F)	32 of 100 (Routine)
Rock Springs AP	United States	Record low maximum temperature	13.3 C (55.9 F)	32 of 100 (Routine)
Geraldton Town	Australia	Record daily precipitation	31.4 mm (1.2 in)	31 of 100 (Routine)
Maunabo	Puerto Rico [United States]	Record daily precipitation	56.6 mm (2.2 in)	31 of 100 (Routine)
Augusta	United States	Record low maximum temperature	17.2 C (63.0 F)	31 of 100 (Routine)
Red Rvr	United States	Record high minimum temperature	12.2 C (54.0 F)	31 of 100 (Routine)
Snake Rvr	United States	Record low maximum temperature	14.4 C (57.9 F)	31 of 100 (Routine)
Yellowstone Park Mammoth	United States	Record low maximum temperature	11.7 C (53.1 F)	31 of 100 (Routine)
Oneonta	United States	Record daily precipitation	48.8 mm (1.9 in)	30 of 100 (Routine)
Caldwell	United States	Record low minimum temperature	3.9 C (39.0 F)	30 of 100 (Routine)
Houlton	United States	Record high minimum temperature	20.6 C (69.1 F)	30 of 100 (Routine)
Ft Benton	United States	Record low maximum temperature	16.7 C (62.1 F)	30 of 100 (Routine)
Dongara	Australia	Record daily precipitation	27.0 mm (1.1 in)	29 of 100 (Routine)
Whitesand Dam	Canada	Record daily precipitation	61.2 mm (2.4 in)	29 of 100 (Routine)

Counts by Type and Timescale

814 records

Records set or tied on 17 August 1978 by type: Highest daily maximum 77, Lowest daily maximum 181, Highest daily minimum 221, Lowest daily minimum 119, Heaviest daily rainfall 212, Heaviest daily snowfall 3, Deepest snow cover 1.

Records on 17 August 1978 by type
Record type	Records
Highest daily maximum	77
Lowest daily maximum	181
Highest daily minimum	221
Lowest daily minimum	119
Heaviest daily rainfall	212
Heaviest daily snowfall	3
Deepest snow cover	1

Records on 17 August 1978 by timescale: all-time 7, monthly 21, daily 786.

How Much Records Were Beaten By

596 broken records

Margins by which the 596 broken records beat the old ones, in degrees Celsius for temperature and millimetres for precipitation and snow; the largest margin was 100.1. Ties are not counted.

Top 20 by Significance

17 August 1978

Top 20 records on 17 August 1978 by significance
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
17 August 1978	Lajas Substn, PR	monthly rain	233.7 mm (9.2 in)	100.1 mm (3.9 in)	15 years	61 of 100 (Major)
17 August 1978	Millstream, AU	monthly rain	58.2 mm (2.3 in)	23.4 mm (0.9 in)	5 years	53 of 100 (Notable)
17 August 1978	Lethbridge A, CA	daily rain	35.8 mm (1.4 in)	33.8 mm (1.3 in)	21 years	50 of 100 (Notable)
17 August 1978	Mayaguez City, PR	daily rain	81.3 mm (3.2 in)	30.8 mm (1.2 in)	69 years	46 of 100 (Notable)
17 August 1978	Paauhau 217, US	daily rain	82.6 mm (3.3 in)	30.3 mm (1.2 in)	64 years	43 of 100 (Notable)
17 August 1978	Boaz, US	daily rain	76.2 mm (3.0 in)	43.7 mm (1.7 in)	28 years	42 of 100 (Notable)
17 August 1978	Dillon U of Montana Western, US	daily low max	13.3 C (55.9 F)	4.5 C (8.1 F)	72 years	40 of 100 (Notable)
17 August 1978	Ft Madison, US	daily rain	43.2 mm (1.7 in)	17.3 mm (0.7 in)	76 years	39 of 100 (Notable)
17 August 1978	Norris Madison Pwr House, US	daily low max	13.3 C (55.9 F)	5.6 C (10.1 F)	65 years	39 of 100 (Notable)
17 August 1978	Middletown 4 W, US	daily high min	23.9 C (75.0 F)	1.1 C (2.0 F)	89 years	38 of 100 (Notable)
17 August 1978	Virginia City, US	daily low min	-1.1 C (30.0 F)	3.9 C (7.0 F)	65 years	38 of 100 (Notable)
17 August 1978	Ny City Cntrl Park, US	daily high min	25.6 C (78.1 F)	0.6 C (1.1 F)	89 years	38 of 100 (Notable)
17 August 1978	Middleton, US	all-time high min	25.0 C (77.0 F)	0.6 C (1.1 F)	40 years	37 of 100 (Notable)
17 August 1978	Bozeman Montana State UNIV, US	daily low max	12.2 C (54.0 F)	3.4 C (6.1 F)	72 years	37 of 100 (Notable)
17 August 1978	Alta 1 NNW, US	daily low max	12.8 C (55.0 F)	4.4 C (7.9 F)	65 years	37 of 100 (Notable)
17 August 1978	Butte Bert Mooney AP, US	daily low max	9.4 C (48.9 F)	3.4 C (6.1 F)	76 years	37 of 100 (Notable)
17 August 1978	Cambridge, US	daily low min	1.7 C (35.1 F)	2.2 C (4.0 F)	78 years	36 of 100 (Notable)
17 August 1978	Hobbs, US	daily high min	25.6 C (78.1 F)	3.4 C (6.1 F)	53 years	36 of 100 (Notable)
17 August 1978	Carmel, US	daily high min	22.8 C (73.0 F)	1.7 C (3.1 F)	77 years	36 of 100 (Notable)
17 August 1978	Kukuihaele Hic 199, US	daily rain	97.8 mm (3.9 in)	38.1 mm (1.5 in)	12 years	36 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 1978

Records set or tied on this calendar date in each year from 1797 to 1978. 1978 had 814 records.

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

Records on 08-17 in each year
Year	Records
1797	2
1802	2
1820	2
1837	1
1838	2
1841	2
1842	1
1845	2
1853	1
1854	1
1856	1
1857	1
1861	3
1862	1
1867	1
1868	3
1869	1
1872	1
1875	2
1876	5
1879	1
1881	1
1882	1
1883	2
1885	3
1886	1
1888	5
1891	1
1892	3
1893	2
1894	3
1895	2
1896	3
1897	1
1898	5
1899	8
1900	3
1901	14
1902	7
1903	6
1904	2
1905	11
1906	28
1907	9
1908	26
1909	24
1910	17
1911	18
1912	31
1913	79
1914	41
1915	28
1916	33
1917	35
1918	112
1919	37
1920	110
1921	37
1922	169
1923	161
1924	171
1925	130
1926	182
1927	228
1928	131
1929	243
1930	138
1931	302
1932	360
1933	260
1934	377
1935	437
1936	670
1937	726
1938	466
1939	364
1940	341
1941	378
1942	461
1943	743
1944	531
1945	387
1946	433
1947	682
1948	475
1949	371
1950	522
1951	413
1952	470
1953	345
1954	685
1955	465
1956	407
1957	504
1958	519
1959	543
1960	533
1961	998
1962	445
1963	650
1964	410
1965	641
1966	496
1967	679
1968	953
1969	593
1970	467
1971	447
1972	1,044
1973	750
1974	582
1975	612
1976	797
1977	1,216
1978	814
1979	1,464
1980	895
1981	1,112
1982	554
1983	1,574
1984	726
1985	948
1986	916
1987	1,150
1988	1,608
1989	687
1990	949
1991	560
1992	1,813
1993	803
1994	1,038
1995	1,724
1996	752
1997	1,544
1998	1,003
1999	697
2000	994
2001	1,101
2002	1,266
2003	948
2004	1,046
2005	722
2006	814
2007	1,646
2008	1,301
2009	922
2010	1,105
2011	956
2012	1,215
2013	802
2014	997
2015	890
2016	748
2017	544
2018	518
2019	467
2020	1,529
2021	800
2022	1,428
2023	1,032
2024	740
2025	538
2026	535

Download the Data

Data for records on 1978-08-17: 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	582
20 to 40	12
40 to 60	1
60 to 80	0
80 to 100	0
100 to 120	1