Fairfax Threshold Days by Year (USC00392820)

21 fixed thresholds counted per year at Fairfax (USC00392820): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Fairfax Thresholds

Fairfax: nights with a minimum temperature at or below 0 C (32 F) in 47 years, most in 1917 with 188.
Fairfax: nights with a minimum temperature at or below -10 C (14 F) in 47 years, most in 1950 with 90.
Fairfax: nights with a minimum temperature at or below -20 C (-4 F) in 47 years, most in 1916 with 43.
Fairfax: nights with a minimum temperature at or above 20 C (68 F) in 47 years, most in 1936 with 42.
21 fixed thresholds have at least one qualifying day at Fairfax.

Days at or above 30 C (86 F)

45 years with a qualifying day

Days per year at Fairfax with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 89 in 1939.

Days at or above 30 C (86 F) per year at Fairfax
Year	Days	Decade average
1904	49	59.8
1905	65	59.8
1906	71	59.8
1908	54	59.8
1912	48	52.5
1913	79	52.5
1914	63	52.5
1915	17	52.5
1916	58	52.5
1917	33	52.5
1918	60	52.5
1919	62	52.5
1920	54	52.4
1921	60	52.4
1922	61	52.4
1923	39	52.4
1924	23	52.4
1925	65	52.4
1926	67	52.4
1927	50	52.4
1928	55	52.4
1929	50	52.4
1930	54	74.8
1931	84	74.8
1932	72	74.8
1933	71	74.8
1934	77	74.8
1935	62	74.8
1936	84	74.8
1937	77	74.8
1938	78	74.8
1939	89	74.8
1940	82	62.1
1941	86	62.1
1943	70	62.1
1944	51	62.1
1945	45	62.1
1946	50	62.1
1947	52	62.1
1948	61	62.1
1950	27	51.8
1951	28	51.8
1952	69	51.8
1953	54	51.8
1955	81	51.8

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

First to last qualifying date each year at Fairfax
Year	First date	Last date
1904	1904-05-22	1904-10-03
1905	1905-05-01	1905-10-06
1906	1906-04-24	1906-09-23
1908	1908-04-12	1908-09-24
1912	1912-05-09	1912-10-05
1913	1913-04-30	1913-10-13
1914	1914-05-26	1914-10-18
1915	1915-05-10	1915-10-24
1916	1916-04-12	1916-09-19
1917	1917-05-18	1917-09-08
1918	1918-05-03	1918-10-16
1919	1919-06-16	1919-09-26
1920	1920-06-08	1920-10-09
1921	1921-03-18	1921-09-23
1922	1922-05-09	1922-10-04
1923	1923-04-19	1923-09-23
1924	1924-04-24	1924-09-06
1925	1925-05-19	1925-09-19
1926	1926-04-20	1926-09-16
1927	1927-04-26	1927-10-26
1928	1928-05-01	1928-10-10
1929	1929-05-14	1929-09-22
1930	1930-04-09	1930-09-23
1931	1931-04-12	1931-09-19
1932	1932-05-13	1932-10-02
1933	1933-05-16	1933-10-14
1934	1934-04-29	1934-10-07
1935	1935-06-09	1935-09-24
1936	1936-05-05	1936-09-25
1937	1937-05-28	1937-10-03
1938	1938-04-29	1938-10-04
1939	1939-04-22	1939-09-24
1940	1940-05-11	1940-10-26
1941	1941-05-12	1941-09-21
1943	1943-03-30	1943-09-26
1944	1944-05-14	1944-10-13
1945	1945-06-22	1945-10-17
1946	1946-03-31	1946-09-26
1947	1947-06-14	1947-10-21
1948	1948-05-14	1948-09-18
1950	1950-05-22	1950-10-30
1951	1951-06-16	1951-10-02
1952	1952-04-27	1952-09-30
1953	1953-05-09	1953-10-18
1955	1955-04-19	1955-10-10

Every Fixed Threshold

Fixed thresholds at Fairfax
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	45	89	1939	81
35 C (95 F): Days	44	55	1936	35
40 C (104 F): Days	19	25	1936	4
45 C (113 F): Days	2	1	1936	1
90 F (32.2 C): Days	45	70	1931	55
100 F (37.8 C): Days	36	38	1936	13
110 F (43.3 C): Days	6	7	1936	1
0 C (32 F): Ice days (max	45	80	1936	59
0 C (32 F): Frost days (min	47	188	1917	141
-10 C (14 F): Days with min	47	90	1950	80
-20 C (-4 F): Days with min	47	43	1916	9
-30 C (-22 F): Days with min	20	6	1905	1
20 C (68 F): Tropical nights (min	47	42	1936	28
25 C (77 F): Days with min	14	6	1936	4
10 mm (0.39 in): Days with 10 mm or more rain	46	32	1944	24
25 mm (0.98 in): Days with 25 mm or more rain	46	13	1908	3
50 mm (1.97 in): Days with 50 mm or more rain	25	4	1908	1
100 mm (3.94 in): Days with 100 mm or more rain	2	1	1914	1
10 cm (3.9 in): Days with 10 cm or more snowfall	42	8	1936	2
25 cm (9.8 in): Days with 25 cm or more snowfall	10	2	1922	1
50 cm (19.7 in): Days with 50 cm or more snowfall	1	0	n/a	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1904.

Download the Data

Data for Fairfax 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).

Fairfax Threshold Days by Year (USC00392820)

Key Facts for Fairfax Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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