Ionia 2SSW Threshold Days by Year (USC00204078)

17 fixed thresholds counted per year at Ionia 2SSW (USC00204078): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Ionia 2SSW Thresholds

Ionia 2SSW: days with 10 mm (0.39 in) or more of precipitation in 64 years, most in 1982 with 36.
Ionia 2SSW: days with 25 mm (0.98 in) or more of precipitation in 64 years, most in 1994 with 14.
Ionia 2SSW: days with a maximum temperature at or above 30 C (86 F) in 62 years, most in 1955 with 67.
Ionia 2SSW: days with a maximum temperature at or below 0 C (32 F) in 62 years, most in 1995 with 79.
17 fixed thresholds have at least one qualifying day at Ionia 2SSW.

Days at or above 30 C (86 F)

62 years with a qualifying day

Days per year at Ionia 2SSW with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 67 in 1955.

Days at or above 30 C (86 F) per year at Ionia 2SSW
Year	Days	Decade average
1897	42	48
1899	54	48
1900	41	46.5
1901	52	46.5
1943	40	43.5
1945	28	43.5
1946	49	43.5
1947	45	43.5
1948	39	43.5
1949	60	43.5
1950	28	41.5
1951	26	41.5
1955	67	41.5
1956	31	41.5
1957	37	41.5
1959	60	41.5
1961	26	24.4
1962	29	24.4
1963	36	24.4
1965	18	24.4
1966	27	24.4
1967	7	24.4
1968	30	24.4
1969	22	24.4
1970	30	40.9
1971	39	40.9
1972	21	40.9
1973	45	40.9
1974	35	40.9
1975	49	40.9
1976	53	40.9
1977	55	40.9
1978	41	40.9
1982	21	35
1983	55	35
1984	38	35
1985	23	35
1986	20	35
1987	51	35
1988	55	35
1989	17	35
1992	7	19.8
1993	15	19.8
1994	15	19.8
1995	29	19.8
1996	14	19.8
1997	17	19.8
1998	31	19.8
1999	30	19.8
2000	4	19.8
2001	26	19.8
2002	33	19.8
2003	17	19.8
2004	9	19.8
2005	38	19.8
2006	17	19.8
2007	35	19.8
2008	14	19.8
2009	5	19.8
2010	19	26.7
2011	23	26.7
2012	38	26.7

For each year, a bar from the first to the last day at Ionia 2SSW meeting 30 C (86 F).

First to last qualifying date each year at Ionia 2SSW
Year	First date	Last date
1897	1897-06-13	1897-10-15
1899	1899-04-29	1899-09-16
1900	1900-06-24	1900-10-06
1901	1901-06-05	1901-09-07
1943	1943-06-13	1943-09-02
1945	1945-06-23	1945-09-08
1946	1946-06-08	1946-09-28
1947	1947-06-10	1947-10-16
1948	1948-06-02	1948-10-01
1949	1949-05-03	1949-09-05
1950	1950-05-25	1950-08-27
1951	1951-05-20	1951-10-04
1955	1955-05-03	1955-09-19
1956	1956-05-30	1956-09-06
1957	1957-05-01	1957-09-11
1959	1959-05-02	1959-09-09
1961	1961-06-11	1961-09-11
1962	1962-05-15	1962-08-31
1963	1963-06-02	1963-09-16
1965	1965-05-07	1965-08-16
1966	1966-06-21	1966-08-31
1967	1967-06-12	1967-07-22
1968	1968-06-06	1968-09-04
1969	1969-05-16	1969-09-06
1970	1970-05-21	1970-09-21
1971	1971-06-04	1971-10-02
1972	1972-05-18	1972-08-30
1973	1973-06-02	1973-09-26
1974	1974-05-21	1974-09-19
1975	1975-05-19	1975-08-28
1976	1976-06-04	1976-09-09
1977	1977-04-18	1977-08-31
1978	1978-05-25	1978-09-20
1982	1982-05-12	1982-09-14
1983	1983-06-12	1983-09-12
1984	1984-06-05	1984-09-19
1985	1985-04-22	1985-09-09
1986	1986-04-26	1986-08-17
1987	1987-05-10	1987-08-16
1988	1988-05-28	1988-08-19
1989	1989-06-07	1989-08-04
1992	1992-06-13	1992-08-26
1993	1993-05-11	1993-08-31
1994	1994-05-23	1994-09-16
1995	1995-06-17	1995-09-06
1996	1996-05-19	1996-08-23
1997	1997-06-11	1997-08-03
1998	1998-05-15	1998-09-27
1999	1999-05-18	1999-09-06
2000	2000-06-10	2000-09-02
2001	2001-06-14	2001-09-08
2002	2002-04-17	2002-09-20
2003	2003-06-19	2003-08-27
2004	2004-04-19	2004-08-28
2005	2005-06-06	2005-09-14
2006	2006-05-29	2006-08-03
2007	2007-05-24	2007-10-09
2008	2008-06-07	2008-09-03
2009	2009-06-24	2009-08-17
2010	2010-05-25	2010-09-24
2011	2011-05-31	2011-09-03
2012	2012-03-22	2012-09-01

Every Fixed Threshold

Fixed thresholds at Ionia 2SSW
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	62	67	1955	38
35 C (95 F): Days	31	27	1988	4
90 F (32.2 C): Days	60	45	1988	16
100 F (37.8 C): Days	5	9	1988	9
0 C (32 F): Ice days (max	62	79	1995	31
0 C (32 F): Frost days (min	61	179	1984	141
-10 C (14 F): Days with min	61	65	1963	10
-20 C (-4 F): Days with min	51	24	1963	2
-30 C (-22 F): Days with min	1	1	1963	1
20 C (68 F): Tropical nights (min	60	21	2002	15
25 C (77 F): Days with min	5	2	2006	1
10 mm (0.39 in): Days with 10 mm or more rain	64	36	1982	25
25 mm (0.98 in): Days with 25 mm or more rain	64	14	1994	6
50 mm (1.97 in): Days with 50 mm or more rain	40	4	1987	2
100 mm (3.94 in): Days with 100 mm or more rain	1	1	1986	1
10 cm (3.9 in): Days with 10 cm or more snowfall	53	7	1965	1
25 cm (9.8 in): Days with 25 cm or more snowfall	7	2	1970	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1897.

Download the Data

Data for Ionia 2SSW 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).

Ionia 2SSW Threshold Days by Year (USC00204078)

Key Facts for Ionia 2SSW Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

Related