Mason City Muni AP Threshold Days by Year (USW00014940)

18 fixed thresholds counted per year at Mason City Muni AP (USW00014940): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Mason City Muni AP Thresholds

Mason City Muni AP: days with a maximum temperature at or above 30 C (86 F) in 79 years, most in 1988 with 61.
Mason City Muni AP: days with a maximum temperature at or above 90 F (32.2 C) in 79 years, most in 2012 with 41.
Mason City Muni AP: days with a maximum temperature at or below 0 C (32 F) in 79 years, most in 1978 with 106.
Mason City Muni AP: nights with a minimum temperature at or below 0 C (32 F) in 79 years, most in 1996 with 185.
18 fixed thresholds have at least one qualifying day at Mason City Muni AP.

Days at or above 30 C (86 F)

79 years with a qualifying day

Days per year at Mason City Muni AP with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 61 in 1988.

Days at or above 30 C (86 F) per year at Mason City Muni AP
Year	Days	Decade average
1948	49	46
1949	43	46
1950	16	29
1951	10	29
1952	35	29
1953	33	29
1954	25	29
1955	51	29
1956	37	29
1957	26	29
1958	22	29
1959	35	29
1960	38	29.1
1961	33	29.1
1962	20	29.1
1963	34	29.1
1964	42	29.1
1965	27	29.1
1966	31	29.1
1967	16	29.1
1968	24	29.1
1969	26	29.1
1970	47	39.8
1971	36	39.8
1972	37	39.8
1973	36	39.8
1974	35	39.8
1975	52	39.8
1976	55	39.8
1977	30	39.8
1978	36	39.8
1979	34	39.8
1980	47	36.9
1981	20	36.9
1982	15	36.9
1983	55	36.9
1984	31	36.9
1985	40	36.9
1986	18	36.9
1987	46	36.9
1988	61	36.9
1989	36	36.9
1990	28	25.9
1991	32	25.9
1992	12	25.9
1993	14	25.9
1994	21	25.9
1995	37	25.9
1996	20	25.9
1997	28	25.9
1998	38	25.9
1999	29	25.9
2000	27	28.8
2001	41	28.8
2002	46	28.8
2003	25	28.8
2004	10	28.8
2005	42	28.8
2006	33	28.8
2007	40	28.8
2008	14	28.8
2009	10	28.8
2010	40	32.7
2011	39	32.7
2012	60	32.7
2013	38	32.7
2014	14	32.7
2015	22	32.7
2016	24	32.7
2017	30	32.7
2018	32	32.7
2019	28	32.7
2020	40	35.7
2021	44	35.7
2022	27	35.7
2023	46	35.7
2024	32	35.7
2025	32	35.7
2026	29	35.7

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

First to last qualifying date each year at Mason City Muni AP
Year	First date	Last date
1948	1948-05-20	1948-09-19
1949	1949-04-25	1949-08-26
1950	1950-06-13	1950-09-18
1951	1951-07-07	1951-08-30
1952	1952-04-29	1952-09-30
1953	1953-05-29	1953-10-02
1954	1954-05-23	1954-09-18
1955	1955-05-02	1955-09-18
1956	1956-05-13	1956-10-12
1957	1957-06-06	1957-08-31
1958	1958-05-11	1958-10-15
1959	1959-05-01	1959-09-08
1960	1960-04-22	1960-09-07
1961	1961-05-11	1961-09-10
1962	1962-04-24	1962-09-12
1963	1963-05-08	1963-10-15
1964	1964-04-16	1964-09-09
1965	1965-05-02	1965-08-26
1966	1966-05-05	1966-09-01
1967	1967-05-18	1967-08-16
1968	1968-04-30	1968-08-23
1969	1969-05-27	1969-08-30
1970	1970-04-27	1970-09-20
1971	1971-06-04	1971-09-30
1972	1972-05-16	1972-09-16
1973	1973-06-07	1973-08-31
1974	1974-06-03	1974-09-26
1975	1975-05-19	1975-10-13
1976	1976-06-06	1976-10-01
1977	1977-05-18	1977-08-27
1978	1978-05-19	1978-09-11
1979	1979-05-17	1979-09-11
1980	1980-04-21	1980-09-19
1981	1981-04-27	1981-09-10
1982	1982-05-04	1982-08-19
1983	1983-06-10	1983-09-09
1984	1984-05-21	1984-09-21
1985	1985-04-17	1985-09-19
1986	1986-05-31	1986-09-26
1987	1987-05-09	1987-09-04
1988	1988-05-14	1988-09-18
1989	1989-05-29	1989-08-31
1990	1990-05-07	1990-09-25
1991	1991-04-06	1991-09-07
1992	1992-04-30	1992-10-02
1993	1993-06-22	1993-10-07
1994	1994-04-18	1994-09-14
1995	1995-06-15	1995-09-13
1996	1996-05-17	1996-08-21
1997	1997-06-13	1997-10-07
1998	1998-05-14	1998-09-26
1999	1999-06-05	1999-09-07
2000	2000-05-04	2000-09-18
2001	2001-05-14	2001-10-02
2002	2002-04-15	2002-09-30
2003	2003-04-14	2003-09-11
2004	2004-04-16	2004-09-13
2005	2005-06-06	2005-10-04
2006	2006-04-13	2006-10-03
2007	2007-04-29	2007-10-06
2008	2008-06-07	2008-09-01
2009	2009-04-24	2009-08-14
2010	2010-04-01	2010-10-09
2011	2011-05-10	2011-09-12
2012	2012-05-18	2012-09-11
2013	2013-05-14	2013-09-27
2014	2014-05-29	2014-09-04
2015	2015-05-03	2015-09-06
2016	2016-05-06	2016-09-21
2017	2017-06-02	2017-09-24
2018	2018-05-24	2018-09-20
2019	2019-04-21	2019-09-30
2020	2020-06-01	2020-09-25
2021	2021-05-01	2021-09-27
2022	2022-05-09	2022-09-20
2023	2023-04-12	2023-10-02
2024	2024-06-03	2024-10-05
2025	2025-05-12	2025-10-04
2026	2026-05-15	2026-10-12

Every Fixed Threshold

Fixed thresholds at Mason City Muni AP
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	79	61	1988	29
35 C (95 F): Days	56	16	2012	1
40 C (104 F): Days	1	1	1980	1
90 F (32.2 C): Days	79	41	2012	8
100 F (37.8 C): Days	14	6	1988	1
0 C (32 F): Ice days (max	79	106	1978	38
0 C (32 F): Frost days (min	79	185	1996	94
-10 C (14 F): Days with min	79	97	1978	34
-20 C (-4 F): Days with min	79	43	1963	9
-30 C (-22 F): Days with min	30	6	1983	1
20 C (68 F): Tropical nights (min	77	28	1975	13
25 C (77 F): Days with min	8	3	1988	1
10 mm (0.39 in): Days with 10 mm or more rain	79	45	2016	25
25 mm (0.98 in): Days with 25 mm or more rain	79	17	1991	5
50 mm (1.97 in): Days with 50 mm or more rain	60	5	2004	2
100 mm (3.94 in): Days with 100 mm or more rain	10	2	1954	1
10 cm (3.9 in): Days with 10 cm or more snowfall	69	7	1983	3
25 cm (9.8 in): Days with 25 cm or more snowfall	11	2	1971	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1948.

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Data for Mason City Muni AP 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 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Mason City Muni AP Threshold Days by Year (USW00014940)

Key Facts for Mason City Muni AP Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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