Riverdale Threshold Days by Year (USC00427318)

17 fixed thresholds counted per year at Riverdale (USC00427318): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Riverdale Thresholds

Riverdale: nights with a minimum temperature at or below 0 C (32 F) in 72 years, most in 1942 with 180.
Riverdale: nights with a minimum temperature at or below -10 C (14 F) in 72 years, most in 1930 with 62.
Riverdale: days with a maximum temperature at or above 30 C (86 F) in 68 years, most in 1919 with 104.
Riverdale: days with a maximum temperature at or above 90 F (32.2 C) in 68 years, most in 1919 with 90.
17 fixed thresholds have at least one qualifying day at Riverdale.

Days at or above 30 C (86 F)

68 years with a qualifying day

Days per year at Riverdale with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 104 in 1919.

Days at or above 30 C (86 F) per year at Riverdale
Year	Days	Decade average
1914	48	68.7
1915	54	68.7
1919	104	68.7
1920	47	67.9
1921	89	67.9
1922	75	67.9
1923	68	67.9
1924	69	67.9
1925	63	67.9
1926	74	67.9
1927	72	67.9
1928	61	67.9
1929	61	67.9
1930	67	65.5
1931	59	65.5
1932	50	65.5
1933	74	65.5
1934	67	65.5
1935	60	65.5
1936	74	65.5
1937	74	65.5
1938	70	65.5
1939	60	65.5
1940	82	64.9
1941	40	64.9
1942	69	64.9
1943	69	64.9
1945	56	64.9
1946	69	64.9
1947	62	64.9
1948	73	64.9
1949	64	64.9
1950	52	66.4
1951	45	66.4
1952	63	66.4
1953	65	66.4
1954	56	66.4
1955	69	66.4
1956	78	66.4
1957	71	66.4
1958	95	66.4
1959	70	66.4
1960	78	68.3
1961	76	68.3
1962	65	68.3
1963	64	68.3
1964	59	68.3
1965	37	68.3
1966	88	68.3
1967	74	68.3
1968	62	68.3
1969	80	68.3
1970	75	69.9
1971	73	69.9
1972	64	69.9
1973	69	69.9
1974	86	69.9
1977	67	69.9
1978	55	69.9
1980	54	64.3
1981	65	64.3
1984	60	64.3
1985	60	64.3
1986	70	64.3
1987	52	64.3
1988	85	64.3
1989	68	64.3
1990	80	80

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

First to last qualifying date each year at Riverdale
Year	First date	Last date
1914	1914-06-17	1914-09-18
1915	1915-06-16	1915-10-31
1919	1919-05-14	1919-09-16
1920	1920-06-07	1920-09-20
1921	1921-05-28	1921-09-29
1922	1922-05-25	1922-09-25
1923	1923-06-09	1923-09-11
1924	1924-06-23	1924-09-14
1925	1925-05-18	1925-09-02
1926	1926-05-22	1926-09-20
1927	1927-05-15	1927-09-06
1928	1928-05-08	1928-09-25
1929	1929-05-24	1929-08-31
1930	1930-05-14	1930-09-04
1931	1931-06-03	1931-09-08
1932	1932-06-23	1932-09-17
1933	1933-05-30	1933-09-20
1934	1934-05-06	1934-09-07
1935	1935-06-07	1935-08-31
1936	1936-05-12	1936-09-09
1937	1937-05-17	1937-09-19
1938	1938-05-26	1938-09-29
1939	1939-05-09	1939-09-21
1940	1940-05-10	1940-09-01
1941	1941-05-12	1941-09-06
1942	1942-05-22	1942-09-08
1943	1943-05-27	1943-09-24
1945	1945-06-21	1945-09-15
1946	1946-06-03	1946-09-14
1947	1947-05-03	1947-09-06
1948	1948-05-16	1948-09-15
1949	1949-06-10	1949-09-24
1950	1950-06-21	1950-09-06
1951	1951-05-27	1951-09-19
1952	1952-06-05	1952-09-10
1953	1953-06-10	1953-09-15
1954	1954-05-19	1954-09-22
1955	1955-06-07	1955-09-14
1956	1956-05-31	1956-09-19
1957	1957-06-03	1957-09-30
1958	1958-05-10	1958-09-22
1959	1959-06-03	1959-09-12
1960	1960-05-10	1960-09-13
1961	1961-05-25	1961-09-06
1962	1962-06-10	1962-09-19
1963	1963-06-20	1963-09-12
1964	1964-05-19	1964-09-08
1965	1965-06-21	1965-08-28
1966	1966-05-04	1966-09-24
1967	1967-05-22	1967-09-29
1968	1968-06-02	1968-09-12
1969	1969-05-23	1969-09-29
1970	1970-05-17	1970-09-08
1971	1971-06-16	1971-09-13
1972	1972-05-16	1972-09-17
1973	1973-05-18	1973-09-13
1974	1974-05-26	1974-09-10
1977	1977-06-02	1977-09-11
1978	1978-06-14	1978-09-08
1980	1980-06-11	1980-09-07
1981	1981-06-12	1981-09-20
1984	1984-05-14	1984-09-20
1985	1985-06-08	1985-09-02
1986	1986-05-28	1986-09-09
1987	1987-06-05	1987-09-03
1988	1988-05-17	1988-09-11
1989	1989-05-08	1989-09-30
1990	1990-05-24	1990-09-17

Every Fixed Threshold

Fixed thresholds at Riverdale
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	68	104	1919	80
35 C (95 F): Days	67	57	1919	21
40 C (104 F): Days	3	2	1930	1
90 F (32.2 C): Days	68	90	1919	55
100 F (37.8 C): Days	31	17	1919	3
0 C (32 F): Ice days (max	68	56	1932	18
0 C (32 F): Frost days (min	72	180	1942	136
-10 C (14 F): Days with min	72	62	1930	30
-20 C (-4 F): Days with min	31	11	1937	8
-30 C (-22 F): Days with min	2	1	1933	1
20 C (68 F): Tropical nights (min	59	17	1914	3
25 C (77 F): Days with min	3	3	1945	1
10 mm (0.39 in): Days with 10 mm or more rain	63	30	1980	6
25 mm (0.98 in): Days with 25 mm or more rain	56	6	1973	1
50 mm (1.97 in): Days with 50 mm or more rain	6	1	1914	1
10 cm (3.9 in): Days with 10 cm or more snowfall	45	10	1929	2
25 cm (9.8 in): Days with 25 cm or more snowfall	3	1	1948	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1914.

Download the Data

Data for Riverdale 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).

Riverdale Threshold Days by Year (USC00427318)

Key Facts for Riverdale Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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