Hartline Threshold Days by Year (USC00453529)

15 fixed thresholds counted per year at Hartline (USC00453529): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Hartline Thresholds

Hartline: nights with a minimum temperature at or below 0 C (32 F) in 55 years, most in 1948 with 173.
Hartline: nights with a minimum temperature at or below -10 C (14 F) in 54 years, most in 1985 with 54.
Hartline: days with a maximum temperature at or above 30 C (86 F) in 51 years, most in 1967 with 83.
Hartline: days with a maximum temperature at or above 90 F (32.2 C) in 51 years, most in 1967 with 62.
15 fixed thresholds have at least one qualifying day at Hartline.

Days at or above 30 C (86 F)

51 years with a qualifying day

Days per year at Hartline with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 83 in 1967.

Days at or above 30 C (86 F) per year at Hartline
Year	Days	Decade average
1930	40	47.6
1932	40	47.6
1933	44	47.6
1936	50	47.6
1937	41	47.6
1938	74	47.6
1939	44	47.6
1940	55	44.3
1941	41	44.3
1942	48	44.3
1943	42	44.3
1944	52	44.3
1945	53	44.3
1946	38	44.3
1948	25	44.3
1953	41	51.2
1956	63	51.2
1957	40	51.2
1958	74	51.2
1959	38	51.2
1960	54	57
1961	63	57
1962	49	57
1967	83	57
1968	43	57
1969	50	57
1970	59	52.1
1971	45	52.1
1972	48	52.1
1973	57	52.1
1974	62	52.1
1975	46	52.1
1976	35	52.1
1977	56	52.1
1978	43	52.1
1979	70	52.1
1980	30	45.6
1981	57	45.6
1983	36	45.6
1984	38	45.6
1985	50	45.6
1986	60	45.6
1987	47	45.6
1988	47	45.6
1990	58	44
1991	42	44
1993	33	44
1996	43	44
2000	41	41
2014	45	43.5
2019	42	43.5

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

First to last qualifying date each year at Hartline
Year	First date	Last date
1930	1930-06-06	1930-09-04
1932	1932-06-11	1932-09-06
1933	1933-06-03	1933-09-02
1936	1936-04-17	1936-09-21
1937	1937-06-01	1937-09-15
1938	1938-05-22	1938-09-23
1939	1939-05-13	1939-09-22
1940	1940-05-22	1940-09-11
1941	1941-05-23	1941-08-21
1942	1942-06-29	1942-09-26
1943	1943-06-28	1943-10-07
1944	1944-05-14	1944-09-12
1945	1945-05-30	1945-09-14
1946	1946-06-13	1946-09-01
1948	1948-06-06	1948-09-14
1953	1953-07-06	1953-09-15
1956	1956-05-18	1956-09-20
1957	1957-05-31	1957-09-25
1958	1958-05-19	1958-09-11
1959	1959-06-03	1959-09-13
1960	1960-06-03	1960-09-15
1961	1961-06-03	1961-08-30
1962	1962-06-17	1962-09-27
1967	1967-06-15	1967-09-28
1968	1968-06-18	1968-09-09
1969	1969-05-23	1969-09-12
1970	1970-05-16	1970-08-31
1971	1971-06-21	1971-08-30
1972	1972-05-28	1972-09-04
1973	1973-05-14	1973-09-12
1974	1974-06-12	1974-09-25
1975	1975-06-01	1975-09-23
1976	1976-06-29	1976-09-30
1977	1977-04-23	1977-08-23
1978	1978-06-02	1978-09-26
1979	1979-05-22	1979-09-21
1980	1980-07-01	1980-09-11
1981	1981-06-25	1981-09-19
1983	1983-05-23	1983-08-31
1984	1984-05-29	1984-09-18
1985	1985-05-17	1985-08-29
1986	1986-05-27	1986-09-05
1987	1987-04-27	1987-09-24
1988	1988-05-12	1988-09-13
1990	1990-06-21	1990-09-24
1991	1991-07-02	1991-09-29
1993	1993-05-11	1993-09-11
1996	1996-06-07	1996-08-31
2000	2000-06-25	2000-09-15
2014	2014-06-23	2014-09-22
2019	2019-06-12	2019-09-07

Every Fixed Threshold

Fixed thresholds at Hartline
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	51	83	1967	42
35 C (95 F): Days	50	36	1958	6
40 C (104 F): Days	15	5	1938	3
90 F (32.2 C): Days	51	62	1967	17
100 F (37.8 C): Days	42	15	1967	2
110 F (43.3 C): Days	2	1	1960	1
0 C (32 F): Ice days (max	51	78	1985	55
0 C (32 F): Frost days (min	55	173	1948	146
-10 C (14 F): Days with min	54	54	1985	24
-20 C (-4 F): Days with min	28	13	1957	4
20 C (68 F): Tropical nights (min	48	11	1961	2
25 C (77 F): Days with min	5	1	1939	1
10 mm (0.39 in): Days with 10 mm or more rain	44	16	1983	4
25 mm (0.98 in): Days with 25 mm or more rain	14	2	1946	2
10 cm (3.9 in): Days with 10 cm or more snowfall	27	8	1996	2

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1930.

Download the Data

Data for Hartline 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).

Hartline Threshold Days by Year (USC00453529)

Key Facts for Hartline Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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