Irwin Threshold Days by Year (USC00364276)

18 fixed thresholds counted per year at Irwin (USC00364276): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Irwin Thresholds

Irwin: days with 10 mm (0.39 in) or more of precipitation in 54 years, most in 1940 with 47.
Irwin: days with 25 mm (0.98 in) or more of precipitation in 54 years, most in 1951 with 12.
Irwin: nights with a minimum temperature at or below 0 C (32 F) in 51 years, most in 1926 with 150.
Irwin: nights with a minimum temperature at or below -10 C (14 F) in 51 years, most in 1917 with 42.
18 fixed thresholds have at least one qualifying day at Irwin.

Days at or above 30 C (86 F)

47 years with a qualifying day

Days per year at Irwin with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 87 in 1908.

Days at or above 30 C (86 F) per year at Irwin
Year	Days	Decade average
1903	40	52.1
1904	46	52.1
1905	50	52.1
1906	67	52.1
1907	37	52.1
1908	87	52.1
1909	38	52.1
1910	40	38.3
1911	71	38.3
1912	31	38.3
1915	38	38.3
1916	44	38.3
1917	27	38.3
1918	19	38.3
1919	36	38.3
1920	3	28.8
1921	57	28.8
1924	16	28.8
1925	57	28.8
1926	45	28.8
1927	26	28.8
1928	12	28.8
1929	14	28.8
1930	39	49.7
1931	42	49.7
1932	63	49.7
1933	45	49.7
1934	56	49.7
1935	28	49.7
1936	69	49.7
1938	45	49.7
1939	60	49.7
1940	50	52.3
1941	65	52.3
1942	56	52.3
1943	54	52.3
1944	63	52.3
1945	53	52.3
1946	39	52.3
1947	47	52.3
1948	41	52.3
1949	55	52.3
1950	22	51
1951	53	51
1952	67	51
1953	69	51
1954	44	51

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

First to last qualifying date each year at Irwin
Year	First date	Last date
1903	1903-05-16	1903-10-04
1904	1904-05-06	1904-10-19
1905	1905-03-29	1905-10-18
1906	1906-05-15	1906-09-23
1907	1907-03-22	1907-09-20
1908	1908-05-18	1908-10-16
1909	1909-06-21	1909-10-10
1910	1910-06-18	1910-10-20
1911	1911-05-11	1911-09-26
1912	1912-05-23	1912-09-15
1915	1915-04-24	1915-10-21
1916	1916-05-15	1916-10-08
1917	1917-06-13	1917-08-22
1918	1918-05-19	1918-08-25
1919	1919-05-30	1919-10-04
1920	1920-10-14	1920-10-21
1921	1921-05-20	1921-09-18
1924	1924-06-19	1924-09-01
1925	1925-04-23	1925-09-21
1926	1926-05-02	1926-10-04
1927	1927-05-21	1927-10-02
1928	1928-05-04	1928-08-30
1929	1929-05-26	1929-09-06
1930	1930-04-11	1930-09-26
1931	1931-05-27	1931-09-21
1932	1932-05-25	1932-09-22
1933	1933-06-06	1933-09-25
1934	1934-05-05	1934-09-25
1935	1935-07-04	1935-09-19
1936	1936-05-07	1936-09-23
1938	1938-04-27	1938-09-07
1939	1939-05-07	1939-10-10
1940	1940-05-19	1940-09-21
1941	1941-04-19	1941-10-07
1942	1942-04-26	1942-09-19
1943	1943-06-03	1943-09-07
1944	1944-05-24	1944-09-04
1945	1945-05-16	1945-09-29
1946	1946-06-11	1946-09-28
1947	1947-05-29	1947-09-20
1948	1948-05-11	1948-09-18
1949	1949-05-04	1949-08-28
1950	1950-06-07	1950-08-29
1951	1951-05-17	1951-10-05
1952	1952-06-06	1952-10-01
1953	1953-05-10	1953-10-04
1954	1954-04-21	1954-09-30

Every Fixed Threshold

Fixed thresholds at Irwin
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	47	87	1908	44
35 C (95 F): Days	30	18	1911	2
40 C (104 F): Days	1	1	1911	1
90 F (32.2 C): Days	46	53	1908	23
100 F (37.8 C): Days	6	4	1936	2
0 C (32 F): Ice days (max	47	39	1926	24
0 C (32 F): Frost days (min	51	150	1926	117
-10 C (14 F): Days with min	51	42	1917	11
-20 C (-4 F): Days with min	33	11	1904	2
-30 C (-22 F): Days with min	1	1	1912	1
20 C (68 F): Tropical nights (min	51	24	1946	5
25 C (77 F): Days with min	1	1	1939	1
10 mm (0.39 in): Days with 10 mm or more rain	54	47	1940	26
25 mm (0.98 in): Days with 25 mm or more rain	54	12	1951	4
50 mm (1.97 in): Days with 50 mm or more rain	30	4	1912	2
10 cm (3.9 in): Days with 10 cm or more snowfall	22	5	1929	2
25 cm (9.8 in): Days with 25 cm or more snowfall	4	2	1927	1
50 cm (19.7 in): Days with 50 cm or more snowfall	1	1	1950	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1903.

Download the Data

Data for Irwin 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).

Irwin Threshold Days by Year (USC00364276)

Key Facts for Irwin Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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