Chatham Threshold Days by Year (CA008100990)

17 fixed thresholds counted per year at Chatham (CA008100990): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Chatham Thresholds

Chatham: days with a maximum temperature at or below 0 C (32 F) in 74 years, most in 1926 with 112.
Chatham: nights with a minimum temperature at or below 0 C (32 F) in 74 years, most in 1875 with 202.
Chatham: nights with a minimum temperature at or below -10 C (14 F) in 74 years, most in 1875 with 115.
Chatham: nights with a minimum temperature at or below -20 C (-4 F) in 74 years, most in 1883 with 56.
17 fixed thresholds have at least one qualifying day at Chatham.

Days at or above 30 C (86 F)

72 years with a qualifying day

Days per year at Chatham with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 24 in 1906.

Days at or above 30 C (86 F) per year at Chatham
Year	Days	Decade average
1873	8	8.6
1874	2	8.6
1875	3	8.6
1876	20	8.6
1877	11	8.6
1878	9	8.6
1879	7	8.6
1880	6	6.6
1881	9	6.6
1882	9	6.6
1883	1	6.6
1884	6	6.6
1886	5	6.6
1887	7	6.6
1888	3	6.6
1889	13	6.6
1890	8	9.6
1891	9	9.6
1892	8	9.6
1893	14	9.6
1894	11	9.6
1895	10	9.6
1896	10	9.6
1897	11	9.6
1898	5	9.6
1899	10	9.6
1900	7	13.3
1901	14	13.3
1902	5	13.3
1904	14	13.3
1905	18	13.3
1906	24	13.3
1907	9	13.3
1908	23	13.3
1909	6	13.3
1910	4	8.5
1911	14	8.5
1912	9	8.5
1913	3	8.5
1914	15	8.5
1915	6	8.5
1916	12	8.5
1917	6	8.5
1918	6	8.5
1919	10	8.5
1920	9	6.8
1921	17	6.8
1922	7	6.8
1923	7	6.8
1924	7	6.8
1925	3	6.8
1926	5	6.8
1927	2	6.8
1928	6	6.8
1929	5	6.8
1930	3	8.2
1931	4	8.2
1932	3	8.2
1933	4	8.2
1934	5	8.2
1935	15	8.2
1936	2	8.2
1937	19	8.2
1938	7	8.2
1939	20	8.2
1940	12	12.4
1941	9	12.4
1942	12	12.4
1943	4	12.4
1944	17	12.4
1945	16	12.4
1946	17	12.4

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

First to last qualifying date each year at Chatham
Year	First date	Last date
1873	1873-06-16	1873-08-14
1874	1874-07-25	1874-08-11
1875	1875-06-27	1875-08-27
1876	1876-06-02	1876-08-15
1877	1877-05-29	1877-08-23
1878	1878-06-01	1878-08-16
1879	1879-05-31	1879-08-03
1880	1880-06-18	1880-09-05
1881	1881-06-12	1881-08-05
1882	1882-07-11	1882-08-31
1883	1883-08-23	1883-08-23
1884	1884-06-17	1884-08-21
1886	1886-07-06	1886-09-08
1887	1887-06-29	1887-08-01
1888	1888-07-03	1888-07-22
1889	1889-05-09	1889-09-13
1890	1890-07-13	1890-08-09
1891	1891-05-29	1891-08-06
1892	1892-06-30	1892-08-04
1893	1893-06-09	1893-08-12
1894	1894-06-15	1894-07-30
1895	1895-05-07	1895-09-23
1896	1896-06-17	1896-08-12
1897	1897-07-05	1897-07-22
1898	1898-07-03	1898-07-30
1899	1899-06-01	1899-08-31
1900	1900-06-07	1900-09-03
1901	1901-05-22	1901-09-07
1902	1902-07-09	1902-08-31
1904	1904-05-08	1904-08-05
1905	1905-06-15	1905-08-22
1906	1906-06-10	1906-08-21
1907	1907-06-13	1907-08-13
1908	1908-06-07	1908-07-31
1909	1909-06-25	1909-08-08
1910	1910-07-07	1910-07-11
1911	1911-05-21	1911-08-10
1912	1912-06-24	1912-07-11
1913	1913-05-06	1913-08-16
1914	1914-05-26	1914-09-23
1915	1915-06-06	1915-09-08
1916	1916-07-11	1916-08-21
1917	1917-06-14	1917-08-02
1918	1918-05-18	1918-08-22
1919	1919-06-06	1919-07-24
1920	1920-05-27	1920-09-24
1921	1921-06-11	1921-09-02
1922	1922-06-05	1922-07-18
1923	1923-06-19	1923-08-03
1924	1924-07-06	1924-08-09
1925	1925-06-04	1925-08-25
1926	1926-07-21	1926-08-02
1927	1927-07-12	1927-07-26
1928	1928-07-11	1928-08-17
1929	1929-06-12	1929-07-29
1930	1930-06-06	1930-06-16
1931	1931-06-20	1931-08-06
1932	1932-05-16	1932-08-06
1933	1933-06-28	1933-08-23
1934	1934-05-29	1934-07-12
1935	1935-07-04	1935-08-21
1936	1936-06-07	1936-06-10
1937	1937-05-31	1937-08-30
1938	1938-06-22	1938-08-16
1939	1939-06-13	1939-09-16
1940	1940-05-27	1940-08-18
1941	1941-06-18	1941-07-24
1942	1942-06-11	1942-09-18
1943	1943-06-25	1943-07-13
1944	1944-05-26	1944-08-16
1945	1945-06-30	1945-09-07
1946	1946-06-24	1946-09-19

Every Fixed Threshold

Fixed thresholds at Chatham
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	72	24	1906	17
35 C (95 F): Days	17	4	1935	4
90 F (32.2 C): Days	59	12	1908	8
100 F (37.8 C): Days	2	2	1935	2
0 C (32 F): Ice days (max	74	112	1926	80
0 C (32 F): Frost days (min	74	202	1875	190
-10 C (14 F): Days with min	74	115	1875	84
-20 C (-4 F): Days with min	74	56	1883	24
-30 C (-22 F): Days with min	58	16	1934	2
-40 C (-40 F): Days with min	1	1	1925	1
20 C (68 F): Tropical nights (min	35	5	1921	1
10 mm (0.39 in): Days with 10 mm or more rain	74	47	1912	25
25 mm (0.98 in): Days with 25 mm or more rain	73	12	1944	5
50 mm (1.97 in): Days with 50 mm or more rain	34	4	1879	1
10 cm (3.9 in): Days with 10 cm or more snowfall	74	19	1887	8
25 cm (9.8 in): Days with 25 cm or more snowfall	35	5	1873	2
50 cm (19.7 in): Days with 50 cm or more snowfall	2	1	1888	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1873.

Download the Data

Data for Chatham 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).

Chatham Threshold Days by Year (CA008100990)

Key Facts for Chatham Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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