Riverdale Threshold Days by Year (USC00327585)

18 fixed thresholds counted per year at Riverdale (USC00327585): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Riverdale Thresholds

Riverdale: days with a maximum temperature at or above 30 C (86 F) in 42 years, most in 1961 with 59.
Riverdale: days with a maximum temperature at or above 90 F (32.2 C) in 42 years, most in 1961 with 38.
Riverdale: days with a maximum temperature at or below 0 C (32 F) in 42 years, most in 1951 with 116.
Riverdale: days with a maximum temperature at or above 35 C (95 F) in 41 years, most in 1959 with 13.
18 fixed thresholds have at least one qualifying day at Riverdale.

Days at or above 30 C (86 F)

42 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 59 in 1961.

Days at or above 30 C (86 F) per year at Riverdale
Year	Days	Decade average
1949	39	39
1950	21	24.3
1951	16	24.3
1952	30	24.3
1953	25	24.3
1954	16	24.3
1955	34	24.3
1956	11	24.3
1957	24	24.3
1958	27	24.3
1959	39	24.3
1960	36	28.4
1961	59	28.4
1962	15	28.4
1963	29	28.4
1964	26	28.4
1965	12	28.4
1966	30	28.4
1967	30	28.4
1968	20	28.4
1969	27	28.4
1970	34	25.7
1971	25	25.7
1972	23	25.7
1973	26	25.7
1974	30	25.7
1975	20	25.7
1976	32	25.7
1977	16	25.7
1978	25	25.7
2006	36	26
2007	26	26
2009	16	26
2010	22	23.5
2012	33	23.5
2013	14	23.5
2015	21	23.5
2016	23	23.5
2017	28	23.5
2022	32	27.7
2023	28	27.7
2024	23	27.7

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
1949	1949-05-13	1949-08-26
1950	1950-06-05	1950-09-06
1951	1951-05-23	1951-08-23
1952	1952-04-27	1952-09-28
1953	1953-06-12	1953-10-02
1954	1954-05-21	1954-09-01
1955	1955-05-03	1955-09-18
1956	1956-05-22	1956-09-27
1957	1957-07-02	1957-10-03
1958	1958-05-12	1958-09-13
1959	1959-06-04	1959-09-14
1960	1960-05-13	1960-09-21
1961	1961-05-31	1961-09-01
1962	1962-04-25	1962-09-07
1963	1963-05-31	1963-10-05
1964	1964-05-21	1964-09-02
1965	1965-07-16	1965-08-14
1966	1966-05-22	1966-09-13
1967	1967-06-28	1967-09-12
1968	1968-06-03	1968-09-15
1969	1969-05-27	1969-09-14
1970	1970-06-06	1970-10-01
1971	1971-07-07	1971-09-04
1972	1972-05-17	1972-09-20
1973	1973-06-02	1973-09-01
1974	1974-06-20	1974-08-25
1975	1975-05-18	1975-08-29
1976	1976-06-03	1976-09-18
1977	1977-05-10	1977-07-30
1978	1978-05-23	1978-09-11
2006	2006-05-19	2006-09-13
2007	2007-05-18	2007-09-29
2009	2009-06-25	2009-09-19
2010	2010-05-30	2010-08-28
2012	2012-03-16	2012-09-12
2013	2013-07-03	2013-09-07
2015	2015-06-30	2015-09-27
2016	2016-05-06	2016-09-02
2017	2017-06-02	2017-09-13
2022	2022-06-19	2022-09-20
2023	2023-06-02	2023-09-19
2024	2024-06-16	2024-10-10

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	42	59	1961	23
35 C (95 F): Days	41	13	1959	3
40 C (104 F): Days	5	1	1960	1
90 F (32.2 C): Days	42	38	1961	10
100 F (37.8 C): Days	19	4	1978	1
0 C (32 F): Ice days (max	42	116	1951	79
0 C (32 F): Frost days (min	41	205	1959	163
-10 C (14 F): Days with min	41	127	1955	68
-20 C (-4 F): Days with min	41	62	1951	18
-30 C (-22 F): Days with min	34	14	1977	3
-40 C (-40 F): Days with min	1	1	1977	1
20 C (68 F): Tropical nights (min	23	7	2012	2
10 mm (0.39 in): Days with 10 mm or more rain	34	17	1954	1
25 mm (0.98 in): Days with 25 mm or more rain	30	7	1956	2
50 mm (1.97 in): Days with 50 mm or more rain	14	2	1951	1
100 mm (3.94 in): Days with 100 mm or more rain	1	1	1966	1
10 cm (3.9 in): Days with 10 cm or more snowfall	12	2	1951	1
25 cm (9.8 in): Days with 25 cm or more snowfall	1	1	1951	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1949.

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 2026-10-12. Last revised 12 October 2026 (2026-10-12).

Riverdale Threshold Days by Year (USC00327585)

Key Facts for Riverdale Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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