Williamson Threshold Days by Year (USC00469605)

17 fixed thresholds counted per year at Williamson (USC00469605): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Williamson Thresholds

Williamson: days with 10 mm (0.39 in) or more of precipitation in 79 years, most in 1929 with 55.
Williamson: days with 25 mm (0.98 in) or more of precipitation in 79 years, most in 1901 with 23.
Williamson: nights with a minimum temperature at or below 0 C (32 F) in 75 years, most in 1976 with 133.
Williamson: nights with a minimum temperature at or above 20 C (68 F) in 75 years, most in 1928 with 61.
17 fixed thresholds have at least one qualifying day at Williamson.

Days at or above 30 C (86 F)

71 years with a qualifying day

Days per year at Williamson with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 129 in 1959.

Days at or above 30 C (86 F) per year at Williamson
Year	Days	Decade average
1901	67	73
1902	68	73
1903	80	73
1904	59	73
1906	72	73
1907	64	73
1908	96	73
1909	78	73
1910	73	64.2
1911	104	64.2
1912	62	64.2
1913	71	64.2
1914	57	64.2
1915	58	64.2
1916	68	64.2
1917	39	64.2
1918	52	64.2
1919	58	64.2
1920	11	40.5
1921	36	40.5
1922	22	40.5
1923	30	40.5
1924	22	40.5
1927	86	40.5
1928	67	40.5
1929	50	40.5
1930	101	90.4
1931	106	90.4
1932	88	90.4
1933	101	90.4
1934	79	90.4
1935	59	90.4
1936	104	90.4
1937	78	90.4
1938	65	90.4
1939	123	90.4
1940	76	93.3
1941	116	93.3
1942	78	93.3
1943	88	93.3
1944	96	93.3
1945	104	93.3
1946	82	93.3
1947	98	93.3
1948	92	93.3
1949	103	93.3
1950	60	103.5
1951	98	103.5
1952	104	103.5
1953	117	103.5
1954	120	103.5
1955	111	103.5
1956	81	103.5
1957	116	103.5
1958	99	103.5
1959	129	103.5
1960	124	97.3
1961	91	97.3
1962	104	97.3
1963	90	97.3
1964	102	97.3
1965	102	97.3
1966	89	97.3
1967	76	97.3
1973	82	75.8
1974	68	75.8
1975	84	75.8
1976	69	75.8
1981	90	97.7
1983	98	97.7
1985	105	97.7

For each year, a bar from the first to the last day at Williamson meeting 30 C (86 F).

First to last qualifying date each year at Williamson
Year	First date	Last date
1901	1901-04-29	1901-09-10
1902	1902-04-25	1902-09-23
1903	1903-04-12	1903-10-07
1904	1904-05-26	1904-10-11
1906	1906-04-14	1906-09-12
1907	1907-03-21	1907-09-24
1908	1908-03-18	1908-10-18
1909	1909-04-05	1909-09-19
1910	1910-03-24	1910-10-06
1911	1911-03-12	1911-10-04
1912	1912-04-12	1912-10-09
1913	1913-04-24	1913-10-10
1914	1914-04-28	1914-09-21
1915	1915-04-20	1915-10-14
1916	1916-04-20	1916-10-08
1917	1917-04-19	1917-09-02
1918	1918-05-05	1918-09-04
1919	1919-05-04	1919-10-02
1920	1920-06-11	1920-07-31
1921	1921-06-01	1921-09-02
1922	1922-06-16	1922-09-08
1923	1923-06-01	1923-08-15
1924	1924-06-18	1924-09-02
1927	1927-04-19	1927-10-03
1928	1928-03-30	1928-10-16
1929	1929-04-07	1929-10-17
1930	1930-04-12	1930-09-27
1931	1931-05-05	1931-10-08
1932	1932-05-05	1932-09-23
1933	1933-04-30	1933-10-02
1934	1934-05-05	1934-09-26
1935	1935-06-19	1935-09-22
1936	1936-04-16	1936-10-10
1937	1937-04-19	1937-09-06
1938	1938-05-04	1938-10-19
1939	1939-04-24	1939-10-27
1940	1940-05-07	1940-09-24
1941	1941-04-14	1941-10-08
1942	1942-04-26	1942-09-20
1943	1943-05-07	1943-09-16
1944	1944-04-23	1944-09-22
1945	1945-03-17	1945-10-23
1946	1946-04-03	1946-11-02
1947	1947-04-06	1947-10-24
1948	1948-04-20	1948-11-06
1949	1949-03-25	1949-10-22
1950	1950-03-28	1950-11-01
1951	1951-04-25	1951-10-07
1952	1952-04-21	1952-10-02
1953	1953-04-10	1953-10-22
1954	1954-03-26	1954-10-15
1955	1955-04-18	1955-10-08
1956	1956-04-28	1956-10-16
1957	1957-04-20	1957-09-23
1958	1958-04-19	1958-11-19
1959	1959-04-02	1959-10-08
1960	1960-04-14	1960-10-16
1961	1961-04-25	1961-11-04
1962	1962-04-26	1962-10-17
1963	1963-03-31	1963-10-20
1964	1964-04-18	1964-09-23
1965	1965-04-12	1965-09-23
1966	1966-03-23	1966-09-11
1967	1967-03-14	1967-10-06
1973	1973-03-15	1973-10-05
1974	1974-04-02	1974-09-14
1975	1975-05-07	1975-10-15
1976	1976-04-16	1976-09-14
1981	1981-04-05	1981-10-02
1983	1983-04-28	1983-10-05
1985	1985-04-06	1985-10-20

Every Fixed Threshold

Fixed thresholds at Williamson
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	71	129	1959	105
35 C (95 F): Days	58	43	1930	14
40 C (104 F): Days	6	2	1930	1
90 F (32.2 C): Days	71	95	1959	57
100 F (37.8 C): Days	22	18	1930	4
0 C (32 F): Ice days (max	70	23	1914	16
0 C (32 F): Frost days (min	75	133	1976	94
-10 C (14 F): Days with min	71	38	1958	20
-20 C (-4 F): Days with min	9	5	1963	3
20 C (68 F): Tropical nights (min	75	61	1928	24
25 C (77 F): Days with min	3	8	1930	1
10 mm (0.39 in): Days with 10 mm or more rain	79	55	1929	36
25 mm (0.98 in): Days with 25 mm or more rain	79	23	1901	5
50 mm (1.97 in): Days with 50 mm or more rain	48	5	1929	1
100 mm (3.94 in): Days with 100 mm or more rain	3	1	1945	1
10 cm (3.9 in): Days with 10 cm or more snowfall	33	4	1947	1
25 cm (9.8 in): Days with 25 cm or more snowfall	3	2	1928	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1901.

Download the Data

Data for Williamson threshold days by year: CSV or JSON. Field meanings are on the data page.

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)) Data as of 2026-10-17 (17 October 2026). Threshold counts are computed by this site.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).

Williamson Threshold Days by Year (USC00469605)

Key Facts for Williamson Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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