Plymouth Threshold Days by Year (USC00276945)

16 fixed thresholds counted per year at Plymouth (USC00276945): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Plymouth Thresholds

Plymouth: days with 10 mm (0.39 in) or more of precipitation in 52 years, most in 1983 with 52.
Plymouth: days with 25 mm (0.98 in) or more of precipitation in 52 years, most in 1973 with 20.
Plymouth: days with 10 cm (3.9 in) or more of snowfall in 52 years, most in 1972 with 15.
Plymouth: nights with a minimum temperature at or below 0 C (32 F) in 50 years, most in 1978 with 217.
16 fixed thresholds have at least one qualifying day at Plymouth.

Days at or above 30 C (86 F)

49 years with a qualifying day

Days per year at Plymouth with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 37 in 1988.

Days at or above 30 C (86 F) per year at Plymouth
Year	Days	Decade average
1952	35	18.4
1956	9	18.4
1957	15	18.4
1958	7	18.4
1959	26	18.4
1960	10	14
1961	10	14
1962	10	14
1963	18	14
1965	21	14
1966	16	14
1967	10	14
1968	16	14
1969	15	14
1970	24	15.9
1971	15	15.9
1972	10	15.9
1973	13	15.9
1975	19	15.9
1976	13	15.9
1977	12	15.9
1978	22	15.9
1979	15	15.9
1980	12	16.4
1981	4	16.4
1982	7	16.4
1983	31	16.4
1984	19	16.4
1985	16	16.4
1986	8	16.4
1987	16	16.4
1988	37	16.4
1989	14	16.4
1990	16	16.3
1991	18	16.3
1992	9	16.3
1993	14	16.3
1994	17	16.3
1995	21	16.3
1996	10	16.3
1997	13	16.3
1998	12	16.3
1999	33	16.3
2000	6	15.8
2002	34	15.8
2003	15	15.8
2004	6	15.8
2005	24	15.8
2006	10	15.8

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

First to last qualifying date each year at Plymouth
Year	First date	Last date
1952	1952-06-15	1952-09-12
1956	1956-06-13	1956-08-19
1957	1957-06-12	1957-09-23
1958	1958-07-01	1958-09-01
1959	1959-05-28	1959-09-25
1960	1960-06-17	1960-09-10
1961	1961-05-16	1961-09-27
1962	1962-04-28	1962-07-09
1963	1963-06-05	1963-10-08
1965	1965-05-11	1965-09-24
1966	1966-05-25	1966-08-10
1967	1967-06-04	1967-08-19
1968	1968-06-07	1968-08-26
1969	1969-05-18	1969-09-02
1970	1970-05-02	1970-09-23
1971	1971-06-08	1971-08-20
1972	1972-05-29	1972-08-25
1973	1973-06-12	1973-09-04
1975	1975-05-21	1975-08-12
1976	1976-04-18	1976-08-23
1977	1977-05-18	1977-08-30
1978	1978-05-21	1978-08-20
1979	1979-05-10	1979-08-06
1980	1980-06-25	1980-08-27
1981	1981-05-26	1981-07-10
1982	1982-07-08	1982-08-09
1983	1983-06-14	1983-09-21
1984	1984-05-24	1984-08-29
1985	1985-05-14	1985-08-16
1986	1986-05-19	1986-07-27
1987	1987-05-30	1987-08-18
1988	1988-05-29	1988-09-03
1989	1989-05-18	1989-09-11
1990	1990-04-28	1990-08-28
1991	1991-05-17	1991-08-31
1992	1992-05-22	1992-08-28
1993	1993-05-12	1993-08-29
1994	1994-05-23	1994-08-05
1995	1995-06-02	1995-08-22
1996	1996-05-21	1996-09-07
1997	1997-06-11	1997-08-17
1998	1998-04-01	1998-08-10
1999	1999-05-31	1999-09-05
2000	2000-05-08	2000-09-02
2002	2002-04-17	2002-09-11
2003	2003-06-24	2003-08-23
2004	2004-04-20	2004-08-04
2005	2005-06-06	2005-08-14
2006	2006-06-19	2006-08-03

Every Fixed Threshold

Fixed thresholds at Plymouth
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	49	37	1988	10
35 C (95 F): Days	12	6	1952	4
90 F (32.2 C): Days	45	21	1988	5
0 C (32 F): Ice days (max	49	79	1978	40
0 C (32 F): Frost days (min	50	217	1978	182
-10 C (14 F): Days with min	50	104	1978	46
-20 C (-4 F): Days with min	50	41	1989	3
-30 C (-22 F): Days with min	12	6	1971	5
20 C (68 F): Tropical nights (min	9	3	2003	2
10 mm (0.39 in): Days with 10 mm or more rain	52	52	1983	37
25 mm (0.98 in): Days with 25 mm or more rain	52	20	1973	9
50 mm (1.97 in): Days with 50 mm or more rain	38	4	1990	3
100 mm (3.94 in): Days with 100 mm or more rain	1	1	1999	1
10 cm (3.9 in): Days with 10 cm or more snowfall	52	15	1972	4
25 cm (9.8 in): Days with 25 cm or more snowfall	29	3	1969	1
50 cm (19.7 in): Days with 50 cm or more snowfall	2	1	1969	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1952.

Download the Data

Data for Plymouth 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).

Plymouth Threshold Days by Year (USC00276945)

Key Facts for Plymouth Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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