Delta Threshold Days by Year (USW00023162)

18 fixed thresholds counted per year at Delta (USW00023162): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Delta Thresholds

Delta: days with a maximum temperature at or above 30 C (86 F) in 78 years, most in 2021 with 127.
Delta: days with a maximum temperature at or above 35 C (95 F) in 78 years, most in 2021 with 75.
Delta: days with a maximum temperature at or above 90 F (32.2 C) in 78 years, most in 2021 with 105.
Delta: nights with a minimum temperature at or below 0 C (32 F) in 78 years, most in 2002 with 212.
18 fixed thresholds have at least one qualifying day at Delta.

Days at or above 30 C (86 F)

78 years with a qualifying day

Days per year at Delta with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 127 in 2021.

Days at or above 30 C (86 F) per year at Delta
Year	Days	Decade average
1939	94	94
1941	83	85.8
1942	91	85.8
1944	78	85.8
1945	75	85.8
1946	93	85.8
1947	85	85.8
1948	88	85.8
1949	93	85.8
1950	77	90.7
1951	85	90.7
1952	94	90.7
1953	94	90.7
1954	89	90.7
1955	87	90.7
1956	103	90.7
1957	82	90.7
1958	106	90.7
1959	90	90.7
1960	96	85
1961	87	85
1962	92	85
1963	88	85
1964	75	85
1965	65	85
1966	99	85
1967	78	85
1971	79	82.2
1972	78	82.2
1973	84	82.2
1974	97	82.2
1975	70	82.2
1976	76	82.2
1977	86	82.2
1978	76	82.2
1979	94	82.2
1980	77	82.7
1981	88	82.7
1982	73	82.7
1983	77	82.7
1984	79	82.7
1985	80	82.7
1986	91	82.7
1987	86	82.7
1988	96	82.7
1989	80	82.7
1990	88	84.3
1991	78	84.3
1992	78	84.3
1993	64	84.3
1994	102	84.3
1995	77	84.3
1996	100	84.3
1997	87	84.3
1998	77	84.3
1999	92	84.3
2000	103	102.6
2001	123	102.6
2002	102	102.6
2003	111	102.6
2004	94	102.6
2005	91	102.6
2006	80	102.6
2007	118	102.6
2008	105	102.6
2009	99	102.6
2010	98	97.8
2011	93	97.8
2012	114	97.8
2013	82	97.8
2018	102	97.8
2020	117	112.9
2021	127	112.9
2022	106	112.9
2023	90	112.9
2024	121	112.9
2025	114	112.9
2026	115	112.9

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

First to last qualifying date each year at Delta
Year	First date	Last date
1939	1939-05-04	1939-09-23
1941	1941-05-10	1941-09-18
1942	1942-05-21	1942-09-29
1944	1944-06-08	1944-09-21
1945	1945-06-19	1945-09-15
1946	1946-06-03	1946-09-29
1947	1947-05-02	1947-10-05
1948	1948-05-16	1948-09-15
1949	1949-04-23	1949-09-25
1950	1950-05-22	1950-10-16
1951	1951-05-25	1951-09-25
1952	1952-06-04	1952-09-27
1953	1953-06-09	1953-10-01
1954	1954-05-07	1954-09-22
1955	1955-05-21	1955-09-14
1956	1956-05-17	1956-10-06
1957	1957-06-02	1957-09-30
1958	1958-05-18	1958-09-22
1959	1959-04-30	1959-09-11
1960	1960-05-10	1960-09-28
1961	1961-05-22	1961-09-15
1962	1962-05-05	1962-09-23
1963	1963-05-06	1963-10-03
1964	1964-05-19	1964-10-08
1965	1965-05-30	1965-10-10
1966	1966-05-03	1966-09-25
1967	1967-05-22	1967-09-21
1971	1971-06-13	1971-09-13
1972	1972-05-15	1972-09-17
1973	1973-05-16	1973-09-19
1974	1974-05-08	1974-10-02
1975	1975-05-14	1975-10-05
1976	1976-05-14	1976-09-05
1977	1977-06-01	1977-09-08
1978	1978-05-14	1978-09-28
1979	1979-05-15	1979-10-07
1980	1980-05-21	1980-09-28
1981	1981-05-01	1981-09-21
1982	1982-05-26	1982-09-24
1983	1983-05-24	1983-09-18
1984	1984-05-13	1984-09-19
1985	1985-05-01	1985-09-15
1986	1986-05-19	1986-09-08
1987	1987-04-17	1987-10-03
1988	1988-05-13	1988-10-04
1989	1989-05-06	1989-09-29
1990	1990-06-03	1990-09-22
1991	1991-06-10	1991-10-16
1992	1992-04-27	1992-10-13
1993	1993-05-11	1993-10-05
1994	1994-04-17	1994-09-28
1995	1995-06-11	1995-09-19
1996	1996-05-12	1996-10-10
1997	1997-05-10	1997-10-05
1998	1998-06-19	1998-09-29
1999	1999-05-23	1999-10-12
2000	2000-04-27	2000-10-03
2001	2001-05-08	2001-10-01
2002	2002-05-17	2002-09-27
2003	2003-05-22	2003-10-19
2004	2004-03-22	2004-10-08
2005	2005-05-19	2005-09-20
2006	2006-05-12	2006-09-13
2007	2007-04-28	2007-09-21
2008	2008-05-17	2008-10-02
2009	2009-04-22	2009-10-18
2010	2010-06-03	2010-10-02
2011	2011-05-07	2011-10-15
2012	2012-04-22	2012-10-02
2013	2013-05-12	2013-09-16
2018	2018-05-09	2018-09-28
2020	2020-04-30	2020-10-09
2021	2021-04-30	2021-09-28
2022	2022-05-06	2022-09-29
2023	2023-04-30	2023-09-27
2024	2024-05-17	2024-10-13
2025	2025-05-03	2025-09-26
2026	2026-03-19	2026-09-17

Every Fixed Threshold

Fixed thresholds at Delta
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	78	127	2021	115
35 C (95 F): Days	78	75	2021	67
40 C (104 F): Days	36	14	2002	16
90 F (32.2 C): Days	78	105	2021	89
100 F (37.8 C): Days	74	44	2022	38
110 F (43.3 C): Days	1	1	2002	1
0 C (32 F): Ice days (max	76	55	1949	3
0 C (32 F): Frost days (min	78	212	2002	80
-10 C (14 F): Days with min	78	84	2002	24
-20 C (-4 F): Days with min	60	34	1949	1
-30 C (-22 F): Days with min	10	5	1949	3
20 C (68 F): Tropical nights (min	35	10	1964	8
10 mm (0.39 in): Days with 10 mm or more rain	74	9	1941	6
25 mm (0.98 in): Days with 25 mm or more rain	16	3	2021	3
50 mm (1.97 in): Days with 50 mm or more rain	2	1	1946	1
100 mm (3.94 in): Days with 100 mm or more rain	1	1	2021	1
10 cm (3.9 in): Days with 10 cm or more snowfall	57	5	1980	1
25 cm (9.8 in): Days with 25 cm or more snowfall	4	1	1954	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1939.

Download the Data

Data for Delta 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 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Delta Threshold Days by Year (USW00023162)

Key Facts for Delta Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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