Ankeny Threshold Days by Year (USC00130241)

18 fixed thresholds counted per year at Ankeny (USC00130241): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Ankeny Thresholds

Ankeny: days with 10 mm (0.39 in) or more of precipitation in 65 years, most in 1993 with 45.
Ankeny: days with 25 mm (0.98 in) or more of precipitation in 65 years, most in 2010 with 21.
Ankeny: days with a maximum temperature at or above 30 C (86 F) in 64 years, most in 2010 with 73.
Ankeny: days with a maximum temperature at or above 90 F (32.2 C) in 64 years, most in 1983 with 51.
18 fixed thresholds have at least one qualifying day at Ankeny.

Days at or above 30 C (86 F)

64 years with a qualifying day

Days per year at Ankeny with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 73 in 2010.

Days at or above 30 C (86 F) per year at Ankeny
Year	Days	Decade average
1951	23	48.1
1952	53	48.1
1953	62	48.1
1954	56	48.1
1955	65	48.1
1956	62	48.1
1957	40	48.1
1958	30	48.1
1959	42	48.1
1960	30	39.7
1961	34	39.7
1962	45	39.7
1963	56	39.7
1964	49	39.7
1965	33	39.7
1966	50	39.7
1967	37	39.7
1968	34	39.7
1969	29	39.7
1970	49	46.6
1971	53	46.6
1972	37	46.6
1974	32	46.6
1975	48	46.6
1976	53	46.6
1977	49	46.6
1978	52	46.6
1980	63	47.6
1981	33	47.6
1982	30	47.6
1983	71	47.6
1984	46	47.6
1985	50	47.6
1986	36	47.6
1987	50	47.6
1988	67	47.6
1989	30	47.6
1990	33	36.8
1991	48	36.8
1992	15	36.8
1993	15	36.8
1994	39	36.8
1995	50	36.8
1996	32	36.8
1997	46	36.8
1998	52	36.8
1999	38	36.8
2000	49	51.6
2001	50	51.6
2002	63	51.6
2003	60	51.6
2004	27	51.6
2005	67	51.6
2006	64	51.6
2007	72	51.6
2008	39	51.6
2009	25	51.6
2010	73	52.5
2011	73	52.5
2013	52	52.5
2015	24	52.5
2016	43	52.5
2017	50	52.5
2020	55	55

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

First to last qualifying date each year at Ankeny
Year	First date	Last date
1951	1951-06-27	1951-08-31
1952	1952-04-29	1952-10-01
1953	1953-05-25	1953-10-15
1954	1954-04-24	1954-09-27
1955	1955-05-02	1955-09-18
1956	1956-05-09	1956-10-12
1957	1957-06-05	1957-09-01
1958	1958-05-11	1958-09-24
1959	1959-06-08	1959-09-08
1960	1960-04-22	1960-09-07
1961	1961-05-12	1961-09-10
1962	1962-05-05	1962-10-10
1963	1963-05-08	1963-10-07
1964	1964-04-16	1964-09-09
1965	1965-04-30	1965-09-10
1966	1966-05-05	1966-09-01
1967	1967-04-16	1967-10-03
1968	1968-04-12	1968-08-24
1969	1969-05-29	1969-08-31
1970	1970-04-29	1970-09-21
1971	1971-05-15	1971-10-02
1972	1972-05-21	1972-09-20
1974	1974-06-15	1974-09-27
1975	1975-05-19	1975-10-14
1976	1976-05-21	1976-10-04
1977	1977-04-10	1977-09-07
1978	1978-05-25	1978-09-16
1980	1980-04-20	1980-09-20
1981	1981-04-02	1981-09-29
1982	1982-05-04	1982-09-11
1983	1983-06-09	1983-10-02
1984	1984-05-17	1984-09-24
1985	1985-04-17	1985-09-19
1986	1986-03-29	1986-09-26
1987	1987-04-20	1987-09-05
1988	1988-05-14	1988-09-17
1989	1989-04-24	1989-08-31
1990	1990-04-24	1990-10-06
1991	1991-04-07	1991-09-15
1992	1992-05-01	1992-08-25
1993	1993-06-18	1993-09-13
1994	1994-04-19	1994-10-02
1995	1995-06-08	1995-09-16
1996	1996-05-18	1996-09-07
1997	1997-05-19	1997-10-08
1998	1998-05-19	1998-09-29
1999	1999-06-06	1999-09-08
2000	2000-05-08	2000-09-19
2001	2001-04-27	2001-09-13
2002	2002-04-16	2002-10-01
2003	2003-04-02	2003-10-21
2004	2004-04-17	2004-09-20
2005	2005-06-07	2005-10-05
2006	2006-04-14	2006-10-04
2007	2007-04-30	2007-10-07
2008	2008-05-26	2008-09-18
2009	2009-04-25	2009-08-15
2010	2010-04-03	2010-10-10
2011	2011-04-11	2011-10-09
2013	2013-05-15	2013-09-28
2015	2015-06-10	2015-09-07
2016	2016-05-31	2016-10-18
2017	2017-05-16	2017-09-25
2020	2020-06-02	2020-09-27

Every Fixed Threshold

Fixed thresholds at Ankeny
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	64	73	2010	55
35 C (95 F): Days	52	25	2011	5
40 C (104 F): Days	2	3	2011	3
90 F (32.2 C): Days	64	51	1983	23
100 F (37.8 C): Days	18	9	2011	2
0 C (32 F): Ice days (max	64	85	1960	40
0 C (32 F): Frost days (min	62	171	1996	153
-10 C (14 F): Days with min	62	73	1978	31
-20 C (-4 F): Days with min	61	31	1963	8
-30 C (-22 F): Days with min	12	5	1996	1
20 C (68 F): Tropical nights (min	62	37	1983	30
25 C (77 F): Days with min	26	7	1988	1
10 mm (0.39 in): Days with 10 mm or more rain	65	45	1993	22
25 mm (0.98 in): Days with 25 mm or more rain	65	21	2010	6
50 mm (1.97 in): Days with 50 mm or more rain	52	5	1982	1
100 mm (3.94 in): Days with 100 mm or more rain	3	1	1954	1
10 cm (3.9 in): Days with 10 cm or more snowfall	49	6	1959	4
25 cm (9.8 in): Days with 25 cm or more snowfall	7	1	1961	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1951.

Download the Data

Data for Ankeny 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).

Ankeny Threshold Days by Year (USC00130241)

Key Facts for Ankeny Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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