Graterford Threshold Days by Year (USC00363435)

16 fixed thresholds counted per year at Graterford (USC00363435): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Graterford Thresholds

Graterford: days with 10 mm (0.39 in) or more of precipitation in 43 years, most in 1952 with 50.
Graterford: days with 25 mm (0.98 in) or more of precipitation in 43 years, most in 1927 with 15.
Graterford: days with 50 mm (1.97 in) or more of precipitation in 29 years, most in 1927 with 5.
Graterford: days with 10 cm (3.9 in) or more of snowfall in 18 years, most in 1934 with 5.
16 fixed thresholds have at least one qualifying day at Graterford.

Days with 10 mm (0.39 in) or more of precipitation

43 years with a qualifying day

Days per year at Graterford with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 50 in 1952.

Days with 10 mm (0.39 in) or more of precipitation per year at Graterford
Year	Days	Decade average
1921	24	32.8
1922	24	32.8
1923	36	32.8
1924	34	32.8
1925	29	32.8
1926	42	32.8
1927	33	32.8
1928	39	32.8
1929	34	32.8
1930	22	32.9
1931	32	32.9
1932	35	32.9
1935	34	32.9
1936	37	32.9
1937	34	32.9
1938	31	32.9
1939	38	32.9
1940	35	36.6
1941	30	36.6
1942	37	36.6
1944	37	36.6
1945	39	36.6
1946	32	36.6
1948	49	36.6
1949	34	36.6
1950	35	36.4
1951	48	36.4
1952	50	36.4
1953	45	36.4
1954	33	36.4
1955	25	36.4
1956	28	36.4
1957	28	36.4
1958	38	36.4
1959	34	36.4
1962	33	32.1
1963	26	32.1
1964	29	32.1
1965	23	32.1
1967	44	32.1
1968	40	32.1
1969	30	32.1
1970	36	36

For each year, a bar from the first to the last day at Graterford meeting 10 mm (0.39 in).

First to last qualifying date each year at Graterford
Year	First date	Last date
1921	1921-01-05	1921-12-04
1922	1922-01-11	1922-12-28
1923	1923-01-01	1923-12-31
1924	1924-01-03	1924-12-08
1925	1925-01-02	1925-11-16
1926	1926-01-21	1926-12-28
1927	1927-01-14	1927-12-08
1928	1928-01-25	1928-11-30
1929	1929-01-10	1929-12-23
1930	1930-01-14	1930-12-27
1931	1931-01-06	1931-12-09
1932	1932-01-01	1932-12-27
1935	1935-01-01	1935-12-16
1936	1936-01-02	1936-12-20
1937	1937-01-03	1937-11-13
1938	1938-01-25	1938-12-27
1939	1939-01-06	1939-12-20
1940	1940-01-15	1940-12-28
1941	1941-01-03	1941-12-24
1942	1942-01-04	1942-12-30
1944	1944-01-04	1944-12-28
1945	1945-01-02	1945-12-26
1946	1946-02-08	1946-12-21
1948	1948-01-02	1948-12-31
1949	1949-01-06	1949-12-27
1950	1950-01-11	1950-12-08
1951	1951-01-15	1951-12-21
1952	1952-01-02	1952-12-22
1953	1953-01-09	1953-12-14
1954	1954-01-10	1954-12-30
1955	1955-02-03	1955-11-11
1956	1956-01-12	1956-12-16
1957	1957-01-23	1957-12-27
1958	1958-01-15	1958-12-30
1959	1959-01-02	1959-12-29
1962	1962-01-07	1962-12-22
1963	1963-01-12	1963-12-24
1964	1964-01-13	1964-12-27
1965	1965-01-08	1965-12-25
1967	1967-01-27	1967-12-29
1968	1968-01-01	1968-12-23
1969	1969-02-10	1969-12-31
1970	1970-02-10	1970-12-23

Every Fixed Threshold

Fixed thresholds at Graterford
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	1	87	1957	87
35 C (95 F): Days	1	8	1957	8
90 F (32.2 C): Days	1	52	1957	52
100 F (37.8 C): Days	1	3	1957	3
0 C (32 F): Ice days (max	1	8	1957	8
0 C (32 F): Frost days (min	1	123	1957	123
-10 C (14 F): Days with min	1	7	1957	7
-20 C (-4 F): Days with min	1	1	1957	1
20 C (68 F): Tropical nights (min	1	10	1957	10
25 C (77 F): Days with min	1	1	1957	1
10 mm (0.39 in): Days with 10 mm or more rain	43	50	1952	36
25 mm (0.98 in): Days with 25 mm or more rain	43	15	1927	9
50 mm (1.97 in): Days with 50 mm or more rain	29	5	1927	3
100 mm (3.94 in): Days with 100 mm or more rain	4	1	1931	1
10 cm (3.9 in): Days with 10 cm or more snowfall	18	5	1934	4
25 cm (9.8 in): Days with 25 cm or more snowfall	4	2	1966	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1957.

Download the Data

Data for Graterford 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).

Graterford Threshold Days by Year (USC00363435)

Key Facts for Graterford Thresholds

Days with 10 mm (0.39 in) or more of precipitation

Every Fixed Threshold

Download the Data

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