Rotan Threshold Days by Year (USC00417782)

16 fixed thresholds counted per year at Rotan (USC00417782): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Rotan Thresholds

Rotan: days with 10 mm (0.39 in) or more of precipitation in 81 years, most in 1941 with 32.
Rotan: days with 25 mm (0.98 in) or more of precipitation in 80 years, most in 1955 with 13.
Rotan: days with 50 mm (1.97 in) or more of precipitation in 63 years, most in 1932 with 5.
Rotan: nights with a minimum temperature at or below 0 C (32 F) in 48 years, most in 1988 with 78.
16 fixed thresholds have at least one qualifying day at Rotan.

Days at or above 30 C (86 F)

41 years with a qualifying day

Days per year at Rotan with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 172 in 1963.

Days at or above 30 C (86 F) per year at Rotan
Year	Days	Decade average
1963	172	141.4
1964	144	141.4
1965	142	141.4
1966	129	141.4
1967	141	141.4
1968	137	141.4
1969	125	141.4
1970	142	137.6
1971	129	137.6
1972	149	137.6
1973	133	137.6
1974	138	137.6
1975	130	137.6
1976	121	137.6
1977	144	137.6
1978	152	137.6
1980	146	142.8
1981	147	142.8
1987	131	142.8
1988	147	142.8
1997	126	139.7
1998	165	139.7
1999	128	139.7
2000	143	137.1
2001	130	137.1
2002	132	137.1
2003	156	137.1
2004	131	137.1
2005	143	137.1
2006	152	137.1
2007	112	137.1
2008	138	137.1
2009	134	137.1
2010	122	138.5
2011	167	138.5
2012	153	138.5
2013	141	138.5
2014	133	138.5
2015	134	138.5
2017	119	138.5
2018	139	138.5

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

First to last qualifying date each year at Rotan
Year	First date	Last date
1963	1963-03-17	1963-10-15
1964	1964-04-03	1964-10-18
1965	1965-04-03	1965-11-25
1966	1966-03-15	1966-10-21
1967	1967-03-04	1967-10-23
1968	1968-04-16	1968-10-31
1969	1969-04-07	1969-10-10
1970	1970-04-11	1970-11-07
1971	1971-03-12	1971-09-29
1972	1972-02-21	1972-10-18
1973	1973-05-08	1973-11-01
1974	1974-03-01	1974-09-27
1975	1975-03-20	1975-10-27
1976	1976-02-09	1976-10-04
1977	1977-03-14	1977-10-29
1978	1978-04-01	1978-10-13
1980	1980-04-06	1980-11-08
1981	1981-02-20	1981-11-25
1987	1987-04-11	1987-11-04
1988	1988-03-10	1988-11-09
1997	1997-03-21	1997-10-09
1998	1998-03-23	1998-10-14
1999	1999-03-22	1999-10-15
2000	2000-02-15	2000-10-06
2001	2001-04-02	2001-10-23
2002	2002-03-13	2002-10-16
2003	2003-03-12	2003-10-30
2004	2004-03-17	2004-10-21
2005	2005-03-12	2005-11-08
2006	2006-02-15	2006-11-09
2007	2007-04-03	2007-11-09
2008	2008-03-15	2008-10-11
2009	2009-02-25	2009-10-21
2010	2010-03-31	2010-11-01
2011	2011-02-28	2011-10-26
2012	2012-03-28	2012-11-09
2013	2013-03-05	2013-10-12
2014	2014-02-20	2014-10-28
2015	2015-03-24	2015-10-16
2017	2017-02-11	2017-11-17
2018	2018-02-20	2018-10-06

Every Fixed Threshold

Fixed thresholds at Rotan
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	41	172	1963	139
35 C (95 F): Days	41	120	1998	89
40 C (104 F): Days	34	45	2011	16
90 F (32.2 C): Days	41	149	2011	112
100 F (37.8 C): Days	40	88	2011	39
110 F (43.3 C): Days	6	3	1980	3
0 C (32 F): Ice days (max	37	12	2015	2
0 C (32 F): Frost days (min	48	78	1988	48
-10 C (14 F): Days with min	38	15	1963	3
20 C (68 F): Tropical nights (min	48	125	2018	125
25 C (77 F): Days with min	38	49	2011	29
10 mm (0.39 in): Days with 10 mm or more rain	81	32	1941	22
25 mm (0.98 in): Days with 25 mm or more rain	80	13	1955	5
50 mm (1.97 in): Days with 50 mm or more rain	63	5	1932	2
100 mm (3.94 in): Days with 100 mm or more rain	7	2	1965	1
10 cm (3.9 in): Days with 10 cm or more snowfall	24	2	1947	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1963.

Download the Data

Data for Rotan 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).

Rotan Threshold Days by Year (USC00417782)

Key Facts for Rotan Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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