Harkness Threshold Days by Year (USC00303662)

17 fixed thresholds counted per year at Harkness (USC00303662): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Harkness Thresholds

Harkness: days with a maximum temperature at or above 30 C (86 F) in 29 years, most in 1911 with 31.
Harkness: days with a maximum temperature at or below 0 C (32 F) in 29 years, most in 1904 with 96.
Harkness: nights with a minimum temperature at or below 0 C (32 F) in 29 years, most in 1904 with 177.
Harkness: nights with a minimum temperature at or below -10 C (14 F) in 29 years, most in 1904 with 99.
17 fixed thresholds have at least one qualifying day at Harkness.

Days at or above 30 C (86 F)

29 years with a qualifying day

Days per year at Harkness with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 31 in 1911.

Days at or above 30 C (86 F) per year at Harkness
Year	Days	Decade average
1903	9	11.7
1904	4	11.7
1905	9	11.7
1906	13	11.7
1907	13	11.7
1908	24	11.7
1909	10	11.7
1910	4	14
1911	31	14
1912	14	14
1913	15	14
1914	14	14
1915	5	14
1916	19	14
1917	10	14
1918	13	14
1919	15	14
1920	7	10.4
1921	29	10.4
1922	7	10.4
1923	13	10.4
1924	8	10.4
1925	8	10.4
1926	3	10.4
1927	2	10.4
1928	9	10.4
1929	18	10.4
1930	14	16
1931	18	16

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

First to last qualifying date each year at Harkness
Year	First date	Last date
1903	1903-04-30	1903-09-15
1904	1904-06-25	1904-07-31
1905	1905-06-16	1905-08-12
1906	1906-05-18	1906-09-10
1907	1907-06-17	1907-08-20
1908	1908-05-29	1908-09-27
1909	1909-06-21	1909-08-25
1910	1910-06-22	1910-07-24
1911	1911-05-11	1911-08-22
1912	1912-06-24	1912-07-15
1913	1913-06-16	1913-09-03
1914	1914-05-27	1914-09-23
1915	1915-07-31	1915-09-16
1916	1916-07-12	1916-08-22
1917	1917-07-18	1917-08-20
1918	1918-05-07	1918-08-23
1919	1919-06-03	1919-09-07
1920	1920-06-01	1920-08-16
1921	1921-05-21	1921-09-10
1922	1922-06-08	1922-09-10
1923	1923-06-18	1923-09-02
1924	1924-07-12	1924-09-01
1925	1925-06-03	1925-09-12
1926	1926-07-10	1926-07-22
1927	1927-06-10	1927-07-13
1928	1928-07-03	1928-08-28
1929	1929-05-28	1929-09-03
1930	1930-05-02	1930-08-08
1931	1931-05-20	1931-09-13

Every Fixed Threshold

Fixed thresholds at Harkness
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	29	31	1911	18
35 C (95 F): Days	13	7	1911	3
90 F (32.2 C): Days	26	17	1911	11
100 F (37.8 C): Days	1	1	1911	1
0 C (32 F): Ice days (max	29	96	1904	54
0 C (32 F): Frost days (min	29	177	1904	147
-10 C (14 F): Days with min	29	99	1904	53
-20 C (-4 F): Days with min	29	29	1914	13
-30 C (-22 F): Days with min	14	4	1914	1
20 C (68 F): Tropical nights (min	29	16	1921	13
25 C (77 F): Days with min	4	3	1911	1
10 mm (0.39 in): Days with 10 mm or more rain	28	32	1918	16
25 mm (0.98 in): Days with 25 mm or more rain	28	10	1918	4
50 mm (1.97 in): Days with 50 mm or more rain	8	2	1924	1
10 cm (3.9 in): Days with 10 cm or more snowfall	1	4	1925	4
25 cm (9.8 in): Days with 25 cm or more snowfall	1	1	1925	1
50 cm (19.7 in): Days with 50 cm or more snowfall	1	1	1925	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1903.

Download the Data

Data for Harkness 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).

Harkness Threshold Days by Year (USC00303662)

Key Facts for Harkness Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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