Arco Threshold Days by Year (USC00100375)

17 fixed thresholds counted per year at Arco (USC00100375): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Arco Thresholds

Arco: days with 10 mm (0.39 in) or more of precipitation in 71 years, most in 1923 with 14.
Arco: nights with a minimum temperature at or below 0 C (32 F) in 70 years, most in 1921 with 223.
Arco: nights with a minimum temperature at or below -10 C (14 F) in 70 years, most in 1964 with 119.
Arco: days with a maximum temperature at or above 30 C (86 F) in 68 years, most in 1937 with 71.
17 fixed thresholds have at least one qualifying day at Arco.

Days at or above 30 C (86 F)

68 years with a qualifying day

Days per year at Arco with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 71 in 1937.

Days at or above 30 C (86 F) per year at Arco
Year	Days	Decade average
1915	20	20
1920	44	44.3
1921	49	44.3
1922	54	44.3
1923	30	44.3
1932	46	54.2
1933	55	54.2
1934	59	54.2
1935	49	54.2
1937	71	54.2
1939	45	54.2
1941	43	39
1947	36	39
1948	38	39
1952	35	35.8
1953	42	35.8
1954	36	35.8
1955	45	35.8
1956	23	35.8
1957	20	35.8
1958	35	35.8
1959	50	35.8
1960	55	33.3
1961	61	33.3
1962	27	33.3
1963	29	33.3
1964	24	33.3
1965	8	33.3
1966	32	33.3
1967	42	33.3
1968	21	33.3
1969	34	33.3
1970	49	38.6
1971	46	38.6
1972	26	38.6
1973	33	38.6
1974	56	38.6
1975	30	38.6
1976	34	38.6
1977	35	38.6
1981	61	52.3
1987	38	52.3
1988	71	52.3
1989	39	52.3
1990	64	48.7
1991	48	48.7
1992	34	48.7
2002	50	53.8
2003	69	53.8
2005	42	53.8
2006	54	53.8
2010	22	37.1
2011	29	37.1
2012	49	37.1
2013	63	37.1
2014	31	37.1
2015	31	37.1
2016	39	37.1
2017	44	37.1
2018	35	37.1
2019	28	37.1
2020	38	43.1
2021	56	43.1
2022	61	43.1
2023	24	43.1
2024	45	43.1
2025	45	43.1
2026	33	43.1

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

First to last qualifying date each year at Arco
Year	First date	Last date
1915	1915-07-05	1915-08-30
1920	1920-06-21	1920-09-16
1921	1921-06-22	1921-08-31
1922	1922-06-03	1922-09-20
1923	1923-04-18	1923-09-12
1932	1932-06-22	1932-09-07
1933	1933-06-11	1933-09-04
1934	1934-05-22	1934-09-07
1935	1935-06-22	1935-09-03
1937	1937-05-09	1937-09-20
1939	1939-05-31	1939-09-20
1941	1941-06-13	1941-08-23
1947	1947-07-02	1947-09-05
1948	1948-06-06	1948-09-15
1952	1952-06-05	1952-09-26
1953	1953-07-05	1953-09-14
1954	1954-05-18	1954-09-01
1955	1955-06-07	1955-09-08
1956	1956-06-27	1956-09-19
1957	1957-06-04	1957-09-07
1958	1958-05-19	1958-09-07
1959	1959-06-12	1959-09-12
1960	1960-06-03	1960-09-12
1961	1961-06-11	1961-08-28
1962	1962-06-23	1962-09-18
1963	1963-07-01	1963-09-12
1964	1964-06-25	1964-08-17
1965	1965-07-15	1965-08-10
1966	1966-05-04	1966-09-23
1967	1967-05-22	1967-09-03
1968	1968-06-19	1968-08-08
1969	1969-06-03	1969-09-01
1970	1970-06-03	1970-08-26
1971	1971-06-22	1971-09-14
1972	1972-06-29	1972-09-04
1973	1973-06-24	1973-08-20
1974	1974-06-12	1974-09-04
1975	1975-07-02	1975-09-09
1976	1976-06-29	1976-09-06
1977	1977-06-01	1977-09-08
1981	1981-06-25	1981-09-17
1987	1987-04-29	1987-09-25
1988	1988-05-16	1988-09-10
1989	1989-06-08	1989-08-18
1990	1990-06-22	1990-09-23
1991	1991-07-02	1991-09-07
1992	1992-04-29	1992-08-22
2002	2002-05-30	2002-09-04
2003	2003-05-24	2003-09-04
2005	2005-06-20	2005-09-08
2006	2006-05-18	2006-09-05
2010	2010-06-28	2010-08-04
2011	2011-06-28	2011-08-28
2012	2012-06-04	2012-08-29
2013	2013-06-08	2013-09-12
2014	2014-07-02	2014-08-18
2015	2015-06-09	2015-09-12
2016	2016-06-05	2016-08-31
2017	2017-06-07	2017-09-07
2018	2018-07-05	2018-08-16
2019	2019-07-09	2019-09-04
2020	2020-05-28	2020-09-06
2021	2021-06-02	2021-09-14
2022	2022-06-17	2022-09-07
2023	2023-07-02	2023-08-30
2024	2024-06-07	2024-09-10
2025	2025-05-31	2025-09-04
2026	2026-05-12	2026-08-01

Every Fixed Threshold

Fixed thresholds at Arco
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	68	71	1937	33
35 C (95 F): Days	47	25	2003	9
90 F (32.2 C): Days	68	44	2003	26
100 F (37.8 C): Days	9	5	2003	5
0 C (32 F): Ice days (max	68	91	2022	13
0 C (32 F): Frost days (min	70	223	1921	83
-10 C (14 F): Days with min	70	119	1964	16
-20 C (-4 F): Days with min	64	55	1922	10
-30 C (-22 F): Days with min	29	15	1937	1
-40 C (-40 F): Days with min	2	1	1937	1
20 C (68 F): Tropical nights (min	7	1	1935	1
10 mm (0.39 in): Days with 10 mm or more rain	71	14	1923	1
25 mm (0.98 in): Days with 25 mm or more rain	21	4	1968	1
50 mm (1.97 in): Days with 50 mm or more rain	1	0	n/a	1
10 cm (3.9 in): Days with 10 cm or more snowfall	34	13	1964	1
25 cm (9.8 in): Days with 25 cm or more snowfall	9	1	1915	1
50 cm (19.7 in): Days with 50 cm or more snowfall	2	1	1915	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1915.

Download the Data

Data for Arco 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 2026-10-12. Last revised 12 October 2026 (2026-10-12).

Arco Threshold Days by Year (USC00100375)

Key Facts for Arco Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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