Dewey Threshold Days by Year

19 fixed thresholds counted per year at Dewey (USC00422150): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Dewey Thresholds

Dewey: nights with a minimum temperature at or below 0 C (32 F) in 32 years, most in 1999 with 190.
Dewey: nights with a minimum temperature at or below -10 C (14 F) in 32 years, most in 1988 with 76.
Dewey: days with 10 mm (0.39 in) or more of precipitation in 31 years, most in 1993 with 20.
Dewey: days with a maximum temperature at or above 30 C (86 F) in 30 years, most in 2001 with 152.
19 fixed thresholds have at least one qualifying day at Dewey.

Days at or above 30 C (86 F)

30 years with a qualifying day

Days per year at Dewey with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 152 in 2001.

Days at or above 30 C (86 F) per year at Dewey
Year	Days	Decade average
1970	103	111.5
1971	101	111.5
1973	107	111.5
1974	126	111.5
1975	107	111.5
1976	106	111.5
1977	119	111.5
1978	123	111.5
1980	120	115.6
1981	124	115.6
1982	103	115.6
1983	101	115.6
1984	110	115.6
1985	111	115.6
1986	99	115.6
1987	137	115.6
1988	117	115.6
1989	134	115.6
1990	113	120.9
1991	125	120.9
1992	127	120.9
1993	115	120.9
1994	136	120.9
1996	132	120.9
1997	119	120.9
1998	116	120.9
1999	105	120.9
2000	110	125.3
2001	152	125.3
2002	114	125.3

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

First to last qualifying date each year at Dewey
Year	First date	Last date
1970	1970-05-05	1970-10-03
1971	1971-05-01	1971-10-14
1973	1973-05-10	1973-10-01
1974	1974-05-06	1974-10-02
1975	1975-05-11	1975-10-06
1976	1976-05-14	1976-10-01
1977	1977-04-23	1977-10-05
1978	1978-05-12	1978-10-10
1980	1980-05-21	1980-10-11
1981	1981-04-18	1981-10-01
1982	1982-04-30	1982-09-26
1983	1983-05-23	1983-09-26
1984	1984-05-09	1984-09-20
1985	1985-04-30	1985-09-17
1986	1986-04-30	1986-09-15
1987	1987-04-17	1987-10-12
1988	1988-05-11	1988-10-04
1989	1989-04-15	1989-10-11
1990	1990-04-15	1990-09-26
1991	1991-05-08	1991-10-17
1992	1992-04-13	1992-10-13
1993	1993-05-11	1993-10-05
1994	1994-04-17	1994-10-11
1996	1996-04-09	1996-10-12
1997	1997-04-18	1997-10-06
1998	1998-04-23	1998-09-30
1999	1999-05-18	1999-10-14
2000	2000-04-26	2000-10-03
2001	2001-04-17	2001-10-07
2002	2002-04-25	2002-09-25

Every Fixed Threshold

Fixed thresholds at Dewey
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	30	152	2001	114
35 C (95 F): Days	30	93	2001	85
40 C (104 F): Days	28	40	1994	34
45 C (113 F): Days	2	1	1989	1
90 F (32.2 C): Days	30	130	2001	107
100 F (37.8 C): Days	30	59	2002	59
110 F (43.3 C): Days	12	4	1990	4
0 C (32 F): Ice days (max	26	35	1992	1
0 C (32 F): Frost days (min	32	190	1999	139
-10 C (14 F): Days with min	32	76	1988	12
-20 C (-4 F): Days with min	16	29	1989	3
-30 C (-22 F): Days with min	2	5	1989	5
20 C (68 F): Tropical nights (min	30	14	1971	2
25 C (77 F): Days with min	7	1	1970	1
10 mm (0.39 in): Days with 10 mm or more rain	31	20	1993	7
25 mm (0.98 in): Days with 25 mm or more rain	10	3	1993	1
50 mm (1.97 in): Days with 50 mm or more rain	3	1	2001	1
100 mm (3.94 in): Days with 100 mm or more rain	1	0	n/a	1
10 cm (3.9 in): Days with 10 cm or more snowfall	15	4	1989	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1970.

Download the Data

Data for Dewey 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).

Dewey Threshold Days by Year

Key Facts for Dewey Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

Related