Castle Rock Weather Records (USC00051401)

Record envelope, standing records and threshold days for Castle Rock (USC00051401), Colorado, United States, with 133 years of record.

Key Facts for Castle Rock

Castle Rock (USC00051401) is a weather station in Colorado, United States at 39.39 latitude and -104.86 longitude, 1,876 m (6,156 ft) above sea level.
The station reports from 1893 to 2025, 133 years of record.
1,464 records set at Castle Rock still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Castle Rock set a daily record high minimum temperature of 15.6 C (60.1 F) on 12 September 2025.

About the Station

Location: Colorado, United States, 39.39 latitude, -104.86 longitude.
Elevation: 1,876 m (6,156 ft).
Period of record: 1893 to 2025, 133 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at Castle Rock. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Castle Rock, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	22.8 C (73.0 F)	-38.3 C (-36.9 F)	n/a	n/a
Feb	23.9 C (75.0 F)	-35.6 C (-32.1 F)	n/a	n/a
Mar	27.8 C (82.0 F)	-28.9 C (-20.0 F)	n/a	n/a
Apr	32.8 C (91.0 F)	-22.2 C (-8.0 F)	n/a	n/a
May	34.4 C (93.9 F)	-13.9 C (7.0 F)	n/a	n/a
Jun	38.3 C (100.9 F)	-3.9 C (25.0 F)	n/a	n/a
Jul	38.9 C (102.0 F)	-1.1 C (30.0 F)	n/a	n/a
Aug	37.2 C (99.0 F)	1.1 C (34.0 F)	n/a	n/a
Sep	38.3 C (100.9 F)	-11.7 C (10.9 F)	n/a	n/a
Oct	31.1 C (88.0 F)	-20.6 C (-5.1 F)	n/a	n/a
Nov	29.4 C (84.9 F)	-27.8 C (-18.0 F)	n/a	n/a
Dec	27.8 C (82.0 F)	-33.9 C (-29.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Castle Rock still stand. 2021 holds the most, with 88.

Standing records at Castle Rock by the year they were set
Year set	Standing records
1893	11
1894	20
1895	19
1896	12
1897	14
1898	13
1899	15
1900	9
1901	7
1902	19
1903	16
1904	13
1905	4
1906	23
1907	32
1908	13
1909	14
1910	9
1911	28
1912	18
1913	22
1914	5
1915	13
1916	18
1917	19
1918	3
1920	6
1921	8
1922	10
1923	8
1924	25
1926	17
1927	17
1928	15
1929	8
1962	6
1963	23
1964	12
1965	11
1966	5
1967	11
1968	8
1969	12
1970	4
1971	13
1972	13
1973	15
1974	12
1975	19
1976	6
1977	7
1978	11
1979	11
1980	3
1981	8
1982	8
1983	15
1984	11
1985	5
1986	14
1987	16
1988	6
1989	22
1990	17
1991	5
1992	7
1993	15
1994	6
1995	13
1996	11
1997	13
1998	6
1999	9
2000	12
2001	9
2002	15
2003	16
2004	15
2005	14
2006	19
2007	10
2008	16
2009	13
2010	17
2011	14
2012	15
2013	9
2014	10
2015	13
2016	20
2017	27
2018	10
2019	23
2020	82
2021	88
2022	51
2023	8
2024	15
2025	11

All-Time Record Progression

9 new records

9 all-time records were set at Castle Rock between 11 January 1963 and 18 July 2022. Each dot is a new record.

When Castle Rock set new all-time records
Date	Kind	Detail
1963-01-11	Record low maximum temperature	Record low maximum temperature -21.1 C (-6.0 F)
1965-06-16	Record daily precipitation	Record daily precipitation 177.8 mm (7.0 in)
1983-12-23	Record low maximum temperature	Record low maximum temperature -22.2 C (-8.0 F)
2003-03-19	Record snow depth	Record snow depth 91.4 cm (36.0 in)
2003-03-20	Record snow depth	Record snow depth 111.8 cm (44.0 in)
2012-06-27	Record high maximum temperature	Record high maximum temperature 37.8 C (100.0 F)
2021-06-16	Record high maximum temperature	Record high maximum temperature 38.3 C (100.9 F)
2022-07-11	Record high maximum temperature	Record high maximum temperature 38.9 C (102.0 F)
2022-07-18	Record high minimum temperature	Record high minimum temperature 22.2 C (72.0 F)

Wettest Day of Each Month

Jun: 177.8 mm (7.0 in)

The wettest day on record for each calendar month at Castle Rock. The most was 177.8 mm (7.0 in) on 16 June 1965.

Record daily precipitation for each month at Castle Rock
Month	Record daily precipitation (mm)	Date
Jan	24.1 mm (0.9 in)	24 January 1921
Feb	38.1 mm (1.5 in)	9 February 1995
Mar	76.2 mm (3.0 in)	19 March 2003
Apr	68.3 mm (2.7 in)	13 April 1967
May	90.2 mm (3.6 in)	12 May 2023
Jun	177.8 mm (7.0 in)	16 June 1965
Jul	74.9 mm (2.9 in)	27 July 2017
Aug	101.6 mm (4.0 in)	3 August 1897
Sep	71.1 mm (2.8 in)	15 September 2013
Oct	76.2 mm (3.0 in)	23 October 1906
Nov	32.3 mm (1.3 in)	18 November 1985
Dec	50.8 mm (2.0 in)	4 December 1913

Period of Record Coverage

1893 to 2025

100 years of record at Castle Rock, 1893 to 2025. 27 years have data for under 90 percent of days and are left out of rankings: 1895, 1898, 1904, 1905, 1909, 1910, 1918, 1920 and others.

Days with data per year at Castle Rock
Year	Days with data	Share of year	Complete
1893	363	99%	Yes
1894	362	99%	Yes
1895	245	67%	No
1896	364	99%	Yes
1897	330	90%	Yes
1898	295	81%	No
1899	362	99%	Yes
1900	364	100%	Yes
1901	364	100%	Yes
1902	363	99%	Yes
1903	364	100%	Yes
1904	263	72%	No
1905	116	32%	No
1906	357	98%	Yes
1907	346	95%	Yes
1908	366	100%	Yes
1909	301	82%	No
1910	285	78%	No
1911	329	90%	Yes
1912	358	98%	Yes
1913	329	90%	Yes
1914	362	99%	Yes
1915	358	98%	Yes
1916	360	98%	Yes
1917	355	97%	Yes
1918	84	23%	No
1920	213	58%	No
1921	362	99%	Yes
1922	364	100%	Yes
1923	362	99%	Yes
1924	363	99%	Yes
1925	30	8%	No
1926	270	74%	No
1927	358	98%	Yes
1928	365	100%	Yes
1929	212	58%	No
1962	260	71%	No
1963	364	100%	Yes
1964	366	100%	Yes
1965	362	99%	Yes
1966	362	99%	Yes
1967	360	99%	Yes
1968	363	99%	Yes
1969	363	99%	Yes
1970	361	99%	Yes
1971	340	93%	Yes
1972	361	99%	Yes
1973	364	100%	Yes
1974	365	100%	Yes
1975	364	100%	Yes
1976	333	91%	Yes
1977	344	94%	Yes
1978	319	87%	No
1979	355	97%	Yes
1980	283	77%	No
1981	346	95%	Yes
1982	330	90%	Yes
1983	317	87%	No
1984	313	86%	No
1985	100	27%	No
1986	342	94%	Yes
1987	348	95%	Yes
1988	358	98%	Yes
1989	343	94%	Yes
1990	335	92%	Yes
1991	200	55%	No
1992	300	82%	No
1993	362	99%	Yes
1994	364	100%	Yes
1995	360	99%	Yes
1996	359	98%	Yes
1997	358	98%	Yes
1998	353	97%	Yes
1999	331	91%	Yes
2000	360	98%	Yes
2001	325	89%	No
2002	359	98%	Yes
2003	351	96%	Yes
2004	356	97%	Yes
2005	362	99%	Yes
2006	361	99%	Yes
2007	364	100%	Yes
2008	366	100%	Yes
2009	302	83%	No
2010	364	100%	Yes
2011	358	98%	Yes
2012	352	96%	Yes
2013	319	87%	No
2014	301	82%	No
2015	312	85%	No
2016	343	94%	Yes
2017	356	98%	Yes
2018	301	82%	No
2019	330	90%	Yes
2020	345	94%	Yes
2021	363	99%	Yes
2022	284	78%	No
2023	365	100%	Yes
2024	365	100%	Yes
2025	271	74%	No

Latest Records

Latest records at Castle Rock
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
12 September 2025	Castle Rock, US	daily high min	15.6 C (60.1 F)	0.6 C (1.1 F)	4 years	12 of 100 (Routine)
11 September 2025	Castle Rock, US	daily high min	16.7 C (62.1 F)	1.7 C (3.1 F)	12 years	16 of 100 (Routine)
15 August 2025	Castle Rock, US	daily high max (Tie)	35.6 C (96.1 F)	tie	114 years	10 of 100 (Routine)
14 July 2025	Castle Rock, US	daily high min (Tie)	18.9 C (66.0 F)	tie	123 years	10 of 100 (Routine)
22 June 2025	Castle Rock, US	daily high max	36.1 C (97.0 F)	1.1 C (2.0 F)	42 years	24 of 100 (Routine)
22 June 2025	Castle Rock, US	daily high min	18.3 C (64.9 F)	2.7 C (4.9 F)	8 years	19 of 100 (Routine)
21 June 2025	Castle Rock, US	daily high min	16.7 C (62.1 F)	0.6 C (1.1 F)	8 years	13 of 100 (Routine)
21 June 2025	Castle Rock, US	daily high max (Tie)	36.1 C (97.0 F)	tie	103 years	10 of 100 (Routine)
4 June 2025	Castle Rock, US	daily low max	12.2 C (54.0 F)	0.6 C (1.1 F)	2 years	11 of 100 (Routine)
14 May 2025	Castle Rock, US	daily high min	12.2 C (54.0 F)	0.5 C (0.9 F)	18 years	16 of 100 (Routine)
13 April 2025	Castle Rock, US	daily high max	29.4 C (84.9 F)	2.2 C (4.0 F)	2 years	13 of 100 (Routine)
28 March 2025	Castle Rock, US	daily high min (Tie)	7.2 C (45.0 F)	tie	62 years	7 of 100 (Routine)
21 February 2025	Castle Rock, US	daily snowfall	14.7 cm (5.8 in)	4.5 cm (1.8 in)	127 years	48 of 100 (Notable)
21 February 2025	Castle Rock, US	daily snow depth	15.2 cm (6.0 in)	2.5 cm (1.0 in)	5 years	15 of 100 (Routine)
12 February 2025	Castle Rock, US	daily low max	-10.0 C (14.0 F)	1.7 C (3.1 F)	39 years	23 of 100 (Routine)
6 February 2025	Castle Rock, US	daily high max (Tie)	18.9 C (66.0 F)	tie	16 years	3 of 100 (Routine)
4 February 2025	Castle Rock, US	daily high max	22.2 C (72.0 F)	2.2 C (4.0 F)	62 years	31 of 100 (Routine)
3 February 2025	Castle Rock, US	daily high min (Tie)	6.7 C (44.1 F)	tie	4 years	2 of 100 (Routine)
21 January 2025	Castle Rock, US	daily low max	-10.6 C (12.9 F)	3.9 C (7.0 F)	119 years	45 of 100 (Notable)
18 January 2025	Castle Rock, US	daily snowfall (Tie)	10.2 cm (4.0 in)	tie	34 years	5 of 100 (Routine)

Climate Trend

67 complete years, 1893 to 2024

One stripe for each of 67 complete years at Castle Rock, 1893 to 2024. Blue stripes are years cooler than the station's own mean of 8.9 C (48.0 F); red stripes are warmer. The coolest year was 1912, at 6.6 C (43.9 F), and the warmest was 2021, at 13.4 C (56.1 F). The strongest colour marks a difference of 4.6 C (8.3 F).

Annual mean temperature at Castle Rock as warming stripes, 1893 to 2024
Year	Annual mean temperature	Difference from the station mean
1893	8.7 C	-0.25 C
1896	8.1 C	-0.83 C
1899	7.6 C	-1.33 C
1900	8.6 C	-0.27 C
1901	9.1 C	+0.17 C
1902	9.2 C	+0.33 C
1903	7.8 C	-1.08 C
1906	8.1 C	-0.82 C
1907	7.0 C	-1.96 C
1908	7.9 C	-1.03 C
1912	6.6 C	-2.29 C
1914	7.9 C	-1.01 C
1915	7.4 C	-1.56 C
1916	7.8 C	-1.12 C
1917	7.5 C	-1.44 C
1921	9.5 C	+0.54 C
1922	8.4 C	-0.53 C
1923	7.7 C	-1.18 C
1924	8.0 C	-0.88 C
1927	8.4 C	-0.49 C
1928	7.8 C	-1.12 C
1963	9.3 C	+0.43 C
1964	8.0 C	-0.95 C
1965	8.4 C	-0.56 C
1966	8.9 C	-0.05 C
1967	9.0 C	+0.05 C
1968	8.5 C	-0.45 C
1969	8.6 C	-0.27 C
1970	8.6 C	-0.34 C
1972	8.1 C	-0.80 C
1973	7.6 C	-1.27 C
1974	7.9 C	-0.97 C
1975	8.0 C	-0.94 C
1977	9.8 C	+0.92 C
1979	8.6 C	-0.33 C
1981	9.9 C	+0.98 C
1982	8.7 C	-0.24 C
1983	8.1 C	-0.78 C
1984	8.0 C	-0.90 C
1986	9.8 C	+0.88 C
1987	8.8 C	-0.10 C
1988	8.8 C	-0.14 C
1990	9.0 C	+0.09 C
1993	7.9 C	-0.98 C
1994	9.9 C	+1.01 C
1995	9.0 C	+0.10 C
1996	9.3 C	+0.38 C
1997	8.5 C	-0.42 C
1998	9.4 C	+0.47 C
2000	9.6 C	+0.64 C
2002	9.1 C	+0.18 C
2003	9.6 C	+0.69 C
2004	8.9 C	-0.01 C
2005	9.5 C	+0.62 C
2006	9.9 C	+1.01 C
2007	9.6 C	+0.70 C
2008	9.0 C	+0.12 C
2010	9.7 C	+0.82 C
2011	9.5 C	+0.55 C
2012	11.1 C	+2.14 C
2016	10.6 C	+1.65 C
2017	10.4 C	+1.48 C
2019	10.2 C	+1.25 C
2020	13.1 C	+4.15 C
2021	13.4 C	+4.50 C
2023	9.6 C	+0.68 C
2024	10.9 C	+1.96 C

The annual mean temperature here has risen by 0.2 C (0.1 to 0.2) per decade over 1893 to 2024. In Fahrenheit: 0.3 F (0.2 to 0.4) per decade. The slope is a straight line fitted to 67 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Castle Rock
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.2 C (0.1 to 0.2) per decade	0.3 F (0.2 to 0.4) per decade	1893 to 2024	67	Rise
Mean daily maximum	0.07 C (0.02 to 0.13) per decade	0.13 F (0.03 to 0.24) per decade	1893 to 2024	67	Rise
Mean daily minimum	0.3 C (0.2 to 0.4) per decade	0.5 F (0.4 to 0.7) per decade	1893 to 2024	67	Rise

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1893 to 2025

Yearly extremes at Castle Rock: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	38.9 C (102.0 F)	2022	35.6 C (96.1 F)	100
Coldest night (TNn)	-38.3 C (-36.9 F)	1913	-26.1 C (-15.0 F)	100
Wettest day (Rx1day)	177.8 mm (7.0 in)	1965	38.4 mm (1.5 in)	104
Wettest five days (Rx5day)	180.8 mm (7.1 in)	1897	57.8 mm (2.3 in)	104
Longest dry spell (CDD)	67 days	2003	30 days	104

Hottest day (TXx)

The hottest day of the year at Castle Rock, 1893 to 2025. The record is 38.9 C (102.0 F) in 2022, marked on the chart; the median year is 35.6 C (96.1 F).

Hottest day (TXx) at Castle Rock by year
Year	Hottest day (TXx)
1893	34.4 C (93.9 F)
1894	36.1 C (97.0 F)
1895	35.0 C (95.0 F)
1896	35.6 C (96.1 F)
1897	36.1 C (97.0 F)
1898	36.7 C (98.1 F)
1899	36.7 C (98.1 F)
1900	35.0 C (95.0 F)
1901	35.0 C (95.0 F)
1902	36.7 C (98.1 F)
1903	35.6 C (96.1 F)
1904	37.2 C (99.0 F)
1905	32.2 C (90.0 F)
1906	37.2 C (99.0 F)
1907	35.0 C (95.0 F)
1908	32.2 C (90.0 F)
1909	32.2 C (90.0 F)
1910	36.1 C (97.0 F)
1911	36.7 C (98.1 F)
1912	33.9 C (93.0 F)
1913	36.1 C (97.0 F)
1914	33.3 C (91.9 F)
1915	36.1 C (97.0 F)
1916	35.0 C (95.0 F)
1917	32.8 C (91.0 F)
1918	33.3 C (91.9 F)
1920	32.2 C (90.0 F)
1921	33.3 C (91.9 F)
1922	36.7 C (98.1 F)
1923	33.3 C (91.9 F)
1924	36.7 C (98.1 F)
1925	15.0 C (59.0 F)
1926	34.4 C (93.9 F)
1927	35.0 C (95.0 F)
1928	35.0 C (95.0 F)
1929	35.0 C (95.0 F)
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1962	35.6 C (96.1 F)
1963	36.7 C (98.1 F)
1964	35.6 C (96.1 F)
1965	33.3 C (91.9 F)
1966	35.6 C (96.1 F)
1967	33.3 C (91.9 F)
1968	35.0 C (95.0 F)
1969	35.6 C (96.1 F)
1970	36.1 C (97.0 F)
1971	36.7 C (98.1 F)
1972	35.0 C (95.0 F)
1973	37.2 C (99.0 F)
1974	33.9 C (93.0 F)
1975	35.6 C (96.1 F)
1976	35.6 C (96.1 F)
1977	36.7 C (98.1 F)
1978	36.1 C (97.0 F)
1979	36.7 C (98.1 F)
1980	36.1 C (97.0 F)
1981	35.6 C (96.1 F)
1982	36.1 C (97.0 F)
1983	35.6 C (96.1 F)
1984	33.9 C (93.0 F)
1985	25.0 C (77.0 F)
1986	34.4 C (93.9 F)
1987	33.9 C (93.0 F)
1988	33.3 C (91.9 F)
1989	35.6 C (96.1 F)
1990	36.1 C (97.0 F)
1991	33.9 C (93.0 F)
1992	33.9 C (93.0 F)
1993	33.9 C (93.0 F)
1994	36.7 C (98.1 F)
1995	36.1 C (97.0 F)
1996	34.4 C (93.9 F)
1997	35.6 C (96.1 F)
1998	36.1 C (97.0 F)
1999	34.4 C (93.9 F)
2000	35.6 C (96.1 F)
2001	35.6 C (96.1 F)
2002	36.7 C (98.1 F)
2003	36.7 C (98.1 F)
2004	35.6 C (96.1 F)
2005	36.7 C (98.1 F)
2006	35.6 C (96.1 F)
2007	35.0 C (95.0 F)
2008	36.7 C (98.1 F)
2009	32.2 C (90.0 F)
2010	36.1 C (97.0 F)
2011	34.4 C (93.9 F)
2012	37.8 C (100.0 F)
2013	35.6 C (96.1 F)
2014	35.6 C (96.1 F)
2015	35.0 C (95.0 F)
2016	35.0 C (95.0 F)
2017	36.7 C (98.1 F)
2018	35.0 C (95.0 F)
2019	37.2 C (99.0 F)
2020	37.2 C (99.0 F)
2021	38.3 C (100.9 F)
2022	38.9 C (102.0 F)
2023	35.6 C (96.1 F)
2024	35.6 C (96.1 F)
2025	36.1 C (97.0 F)

Coldest night (TNn)

The coldest night of the year at Castle Rock, 1893 to 2025. The record is -38.3 C (-36.9 F) in 1913, marked on the chart; the median year is -26.1 C (-15.0 F).

Coldest night (TNn) at Castle Rock by year
Year	Coldest night (TNn)
1893	-19.4 C (-2.9 F)
1894	-25.6 C (-14.1 F)
1895	-24.4 C (-11.9 F)
1896	-25.0 C (-13.0 F)
1897	-29.4 C (-20.9 F)
1898	-30.0 C (-22.0 F)
1899	-35.6 C (-32.1 F)
1900	-33.9 C (-29.0 F)
1901	-30.0 C (-22.0 F)
1902	-30.6 C (-23.1 F)
1903	-28.3 C (-18.9 F)
1904	-23.3 C (-9.9 F)
1905	-24.4 C (-11.9 F)
1906	-28.9 C (-20.0 F)
1907	-24.4 C (-11.9 F)
1908	-25.0 C (-13.0 F)
1909	-33.3 C (-27.9 F)
1910	-27.2 C (-17.0 F)
1911	-35.0 C (-31.0 F)
1912	-28.9 C (-20.0 F)
1913	-38.3 C (-36.9 F)
1914	-27.2 C (-17.0 F)
1915	-28.3 C (-18.9 F)
1916	-30.0 C (-22.0 F)
1917	-26.7 C (-16.1 F)
1918	-30.0 C (-22.0 F)
1920	-22.8 C (-9.0 F)
1921	-21.7 C (-7.1 F)
1922	-27.8 C (-18.0 F)
1923	-33.3 C (-27.9 F)
1924	-32.8 C (-27.0 F)
1925	-23.9 C (-11.0 F)
1926	-30.0 C (-22.0 F)
1927	-31.7 C (-25.1 F)
1928	-27.8 C (-18.0 F)
1929	-32.8 C (-27.0 F)
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1962	-24.4 C (-11.9 F)
1963	-37.2 C (-35.0 F)
1964	-27.8 C (-18.0 F)
1965	-25.6 C (-14.1 F)
1966	-26.7 C (-16.1 F)
1967	-25.6 C (-14.1 F)
1968	-26.7 C (-16.1 F)
1969	-24.4 C (-11.9 F)
1970	-27.8 C (-18.0 F)
1971	-22.2 C (-8.0 F)
1972	-32.2 C (-26.0 F)
1973	-26.1 C (-15.0 F)
1974	-30.0 C (-22.0 F)
1975	-30.0 C (-22.0 F)
1976	-27.8 C (-18.0 F)
1977	-25.6 C (-14.1 F)
1978	-30.6 C (-23.1 F)
1979	-28.3 C (-18.9 F)
1980	-23.3 C (-9.9 F)
1981	-27.8 C (-18.0 F)
1982	-33.9 C (-29.0 F)
1983	-31.1 C (-24.0 F)
1984	-30.0 C (-22.0 F)
1985	-26.1 C (-15.0 F)
1986	-22.2 C (-8.0 F)
1987	-21.1 C (-6.0 F)
1988	-22.2 C (-8.0 F)
1989	-31.7 C (-25.1 F)
1990	-32.2 C (-26.0 F)
1991	-20.0 C (-4.0 F)
1992	-18.9 C (-2.0 F)
1993	-23.3 C (-9.9 F)
1994	-25.0 C (-13.0 F)
1995	-22.2 C (-8.0 F)
1996	-26.7 C (-16.1 F)
1997	-24.4 C (-11.9 F)
1998	-24.4 C (-11.9 F)
1999	-18.3 C (-0.9 F)
2000	-19.4 C (-2.9 F)
2001	-26.1 C (-15.0 F)
2002	-23.9 C (-11.0 F)
2003	-24.4 C (-11.9 F)
2004	-25.6 C (-14.1 F)
2005	-24.4 C (-11.9 F)
2006	-25.6 C (-14.1 F)
2007	-25.6 C (-14.1 F)
2008	-23.9 C (-11.0 F)
2009	-26.1 C (-15.0 F)
2010	-21.7 C (-7.1 F)
2011	-26.7 C (-16.1 F)
2012	-18.9 C (-2.0 F)
2013	-26.1 C (-15.0 F)
2014	-27.2 C (-17.0 F)
2015	-18.3 C (-0.9 F)
2016	-23.3 C (-9.9 F)
2017	-21.1 C (-6.0 F)
2018	-20.6 C (-5.1 F)
2019	-21.1 C (-6.0 F)
2020	-18.9 C (-2.0 F)
2021	-20.6 C (-5.1 F)
2022	-25.6 C (-14.1 F)
2023	-21.7 C (-7.1 F)
2024	-27.8 C (-18.0 F)
2025	-23.9 C (-11.0 F)

Wettest day (Rx1day)

The wettest day of the year at Castle Rock, 1893 to 2025. The record is 177.8 mm (7.0 in) in 1965, marked on the chart; the median year is 38.4 mm (1.5 in).

Wettest day (Rx1day) at Castle Rock by year
Year	Wettest day (Rx1day)
1893	23.4 mm (0.9 in)
1894	72.1 mm (2.8 in)
1895	53.3 mm (2.1 in)
1896	25.4 mm (1.0 in)
1897	101.6 mm (4.0 in)
1898	32.3 mm (1.3 in)
1899	22.9 mm (0.9 in)
1900	35.6 mm (1.4 in)
1901	55.9 mm (2.2 in)
1902	39.4 mm (1.6 in)
1903	15.2 mm (0.6 in)
1904	44.5 mm (1.8 in)
1905	17.3 mm (0.7 in)
1906	76.2 mm (3.0 in)
1907	34.0 mm (1.3 in)
1908	30.5 mm (1.2 in)
1909	30.5 mm (1.2 in)
1910	58.4 mm (2.3 in)
1911	18.5 mm (0.7 in)
1912	43.7 mm (1.7 in)
1913	50.8 mm (2.0 in)
1914	37.3 mm (1.5 in)
1915	30.5 mm (1.2 in)
1916	73.4 mm (2.9 in)
1917	31.0 mm (1.2 in)
1918	24.6 mm (1.0 in)
1920	23.4 mm (0.9 in)
1921	70.6 mm (2.8 in)
1922	28.4 mm (1.1 in)
1923	44.2 mm (1.7 in)
1924	32.0 mm (1.3 in)
1925	0.0 mm (0.00 in)
1926	38.4 mm (1.5 in)
1927	62.7 mm (2.5 in)
1928	28.7 mm (1.1 in)
1929	28.4 mm (1.1 in)
1948	19.1 mm (0.8 in)
1949	42.9 mm (1.7 in)
1950	35.1 mm (1.4 in)
1951	21.6 mm (0.9 in)
1962	28.2 mm (1.1 in)
1963	40.1 mm (1.6 in)
1964	49.3 mm (1.9 in)
1965	177.8 mm (7.0 in)
1966	30.5 mm (1.2 in)
1967	68.3 mm (2.7 in)
1968	17.8 mm (0.7 in)
1969	57.7 mm (2.3 in)
1970	35.6 mm (1.4 in)
1971	19.8 mm (0.8 in)
1972	42.4 mm (1.7 in)
1973	75.7 mm (3.0 in)
1974	37.6 mm (1.5 in)
1975	46.2 mm (1.8 in)
1976	30.5 mm (1.2 in)
1977	35.8 mm (1.4 in)
1978	31.8 mm (1.3 in)
1979	29.2 mm (1.1 in)
1980	38.1 mm (1.5 in)
1981	26.7 mm (1.1 in)
1982	53.6 mm (2.1 in)
1983	39.1 mm (1.5 in)
1984	27.2 mm (1.1 in)
1985	32.3 mm (1.3 in)
1986	54.9 mm (2.2 in)
1987	43.7 mm (1.7 in)
1988	44.7 mm (1.8 in)
1989	46.5 mm (1.8 in)
1990	36.8 mm (1.4 in)
1991	30.5 mm (1.2 in)
1992	42.7 mm (1.7 in)
1993	23.4 mm (0.9 in)
1994	50.8 mm (2.0 in)
1995	52.1 mm (2.1 in)
1996	34.3 mm (1.4 in)
1997	46.2 mm (1.8 in)
1998	55.9 mm (2.2 in)
1999	40.6 mm (1.6 in)
2000	31.0 mm (1.2 in)
2001	63.5 mm (2.5 in)
2002	39.9 mm (1.6 in)
2003	76.2 mm (3.0 in)
2004	50.3 mm (2.0 in)
2005	56.1 mm (2.2 in)
2006	66.0 mm (2.6 in)
2007	22.9 mm (0.9 in)
2008	33.0 mm (1.3 in)
2009	40.4 mm (1.6 in)
2010	38.9 mm (1.5 in)
2011	27.7 mm (1.1 in)
2012	88.9 mm (3.5 in)
2013	71.1 mm (2.8 in)
2014	38.1 mm (1.5 in)
2015	66.0 mm (2.6 in)
2016	43.2 mm (1.7 in)
2017	74.9 mm (2.9 in)
2018	31.0 mm (1.2 in)
2019	26.9 mm (1.1 in)
2020	24.9 mm (1.0 in)
2021	38.6 mm (1.5 in)
2022	38.4 mm (1.5 in)
2023	90.2 mm (3.6 in)
2024	43.4 mm (1.7 in)
2025	25.7 mm (1.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Castle Rock, 1893 to 2025. The record is 180.8 mm (7.1 in) in 1897, marked on the chart; the median year is 57.8 mm (2.3 in).

Wettest five days (Rx5day) at Castle Rock by year
Year	Wettest five days (Rx5day)
1893	44.3 mm (1.7 in)
1894	72.1 mm (2.8 in)
1895	96.5 mm (3.8 in)
1896	57.2 mm (2.3 in)
1897	180.8 mm (7.1 in)
1898	77.1 mm (3.0 in)
1899	27.9 mm (1.1 in)
1900	67.4 mm (2.7 in)
1901	73.2 mm (2.9 in)
1902	69.1 mm (2.7 in)
1903	48.0 mm (1.9 in)
1904	74.9 mm (2.9 in)
1905	17.3 mm (0.7 in)
1906	76.2 mm (3.0 in)
1907	55.9 mm (2.2 in)
1908	35.6 mm (1.4 in)
1909	46.0 mm (1.8 in)
1910	69.1 mm (2.7 in)
1911	52.7 mm (2.1 in)
1912	65.5 mm (2.6 in)
1913	104.3 mm (4.1 in)
1914	58.7 mm (2.3 in)
1915	64.3 mm (2.5 in)
1916	83.3 mm (3.3 in)
1917	45.2 mm (1.8 in)
1918	44.5 mm (1.8 in)
1920	36.1 mm (1.4 in)
1921	104.4 mm (4.1 in)
1922	45.2 mm (1.8 in)
1923	72.7 mm (2.9 in)
1924	72.3 mm (2.8 in)
1925	3.0 mm (0.12 in)
1926	39.4 mm (1.6 in)
1927	62.7 mm (2.5 in)
1928	44.7 mm (1.8 in)
1929	36.3 mm (1.4 in)
1948	25.4 mm (1.0 in)
1949	53.3 mm (2.1 in)
1950	56.7 mm (2.2 in)
1951	51.3 mm (2.0 in)
1962	47.5 mm (1.9 in)
1963	50.3 mm (2.0 in)
1964	60.5 mm (2.4 in)
1965	179.3 mm (7.1 in)
1966	40.1 mm (1.6 in)
1967	68.3 mm (2.7 in)
1968	27.6 mm (1.1 in)
1969	151.0 mm (5.9 in)
1970	57.2 mm (2.3 in)
1971	30.5 mm (1.2 in)
1972	56.6 mm (2.2 in)
1973	89.9 mm (3.5 in)
1974	59.5 mm (2.3 in)
1975	50.3 mm (2.0 in)
1976	40.2 mm (1.6 in)
1977	49.3 mm (1.9 in)
1978	49.7 mm (2.0 in)
1979	46.2 mm (1.8 in)
1980	60.5 mm (2.4 in)
1981	33.5 mm (1.3 in)
1982	56.6 mm (2.2 in)
1983	70.1 mm (2.8 in)
1984	62.0 mm (2.4 in)
1985	41.4 mm (1.6 in)
1986	75.5 mm (3.0 in)
1987	73.6 mm (2.9 in)
1988	75.2 mm (3.0 in)
1989	51.8 mm (2.0 in)
1990	55.2 mm (2.2 in)
1991	32.5 mm (1.3 in)
1992	75.7 mm (3.0 in)
1993	52.1 mm (2.1 in)
1994	50.8 mm (2.0 in)
1995	87.7 mm (3.5 in)
1996	66.6 mm (2.6 in)
1997	71.9 mm (2.8 in)
1998	71.9 mm (2.8 in)
1999	99.9 mm (3.9 in)
2000	46.0 mm (1.8 in)
2001	63.5 mm (2.5 in)
2002	43.2 mm (1.7 in)
2003	169.9 mm (6.7 in)
2004	62.5 mm (2.5 in)
2005	72.9 mm (2.9 in)
2006	90.4 mm (3.6 in)
2007	35.3 mm (1.4 in)
2008	73.9 mm (2.9 in)
2009	44.0 mm (1.7 in)
2010	81.0 mm (3.2 in)
2011	58.9 mm (2.3 in)
2012	89.7 mm (3.5 in)
2013	125.9 mm (5.0 in)
2014	59.7 mm (2.4 in)
2015	107.1 mm (4.2 in)
2016	48.3 mm (1.9 in)
2017	103.8 mm (4.1 in)
2018	48.2 mm (1.9 in)
2019	47.5 mm (1.9 in)
2020	27.0 mm (1.1 in)
2021	58.2 mm (2.3 in)
2022	45.3 mm (1.8 in)
2023	137.7 mm (5.4 in)
2024	57.4 mm (2.3 in)
2025	52.6 mm (2.1 in)

Longest dry spell (CDD)

The longest dry spell of the year at Castle Rock, 1893 to 2025. The record is 67 days in 2003, marked on the chart; the median year is 30 days.

Longest dry spell (CDD) at Castle Rock by year
Year	Longest dry spell (CDD)
1893	31 days
1894	47 days
1895	22 days
1896	32 days
1897	28 days
1898	29 days
1899	44 days
1900	34 days
1901	55 days
1902	30 days
1903	31 days
1904	22 days
1905	27 days
1906	43 days
1907	52 days
1908	25 days
1909	44 days
1910	41 days
1911	45 days
1912	33 days
1913	26 days
1914	29 days
1915	27 days
1916	29 days
1917	34 days
1918	31 days
1920	24 days
1921	29 days
1922	48 days
1923	32 days
1924	52 days
1925	31 days
1926	27 days
1927	27 days
1928	29 days
1929	18 days
1948	31 days
1949	31 days
1950	31 days
1951	23 days
1962	33 days
1963	57 days
1964	36 days
1965	36 days
1966	47 days
1967	24 days
1968	21 days
1969	29 days
1970	35 days
1971	31 days
1972	30 days
1973	22 days
1974	27 days
1975	34 days
1976	26 days
1977	25 days
1978	41 days
1979	28 days
1980	45 days
1981	24 days
1982	33 days
1983	31 days
1984	39 days
1985	21 days
1986	30 days
1987	26 days
1988	27 days
1989	26 days
1990	35 days
1991	35 days
1992	35 days
1993	25 days
1994	22 days
1995	27 days
1996	25 days
1997	25 days
1998	39 days
1999	23 days
2000	29 days
2001	50 days
2002	47 days
2003	67 days
2004	28 days
2005	26 days
2006	34 days
2007	29 days
2008	35 days
2009	24 days
2010	48 days
2011	30 days
2012	43 days
2013	28 days
2014	28 days
2015	49 days
2016	46 days
2017	37 days
2018	28 days
2019	23 days
2020	46 days
2021	25 days
2022	31 days
2023	22 days
2024	26 days
2025	14 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Frost Dates and Growing Season

67 years with a frost

Across 67 years with a frost, the median last spring frost at Castle Rock falls on 20 May and the median first autumn frost on 23 September, which leaves a median of 130 days between them.

In 1983 to 2024 the median growing season was 138 days. That is 17 days more than in 1893 to 1972.

Fitted over all years, the growing season changes by +3.2 days per decade at this station.

Frost dates and growing season at Castle Rock
Measure	Median, all years	Earliest period (1893 to 1972)	Recent period (1983 to 2024)	Recent against earliest	Fitted trend
Last spring frost	20 May	23 May	14 May	9 days earlier	-1.3 days per decade
First autumn frost	23 September	21 September	5 October	14 days later	+1.9 days per decade
Growing days	130 days	121 days	138 days	17 days more	+3.2 days per decade

A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.

Rainfall Return Levels

75 years, 1893 to 2024

A day with at least 41.6 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 134.1 mm (5.3 in) of rain is expected about once in 100 years.

Rainfall return levels at Castle Rock: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	41.6 mm (1.6 in)
5 years	60.0 mm (2.4 in)
10 years	74.4 mm (2.9 in)
25 years	95.6 mm (3.8 in)
50 years	113.7 mm (4.5 in)
100 years	134.1 mm (5.3 in)	Longer than the 75 years of record

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 75 years of values from 1893 to 2024.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 177.8 mm (7.0 in) in 1965; 101.6 mm (4.0 in) in 1897; 90.2 mm (3.6 in) in 2023.

Station Changes

No change in the annual mean temperature of this station was found against its neighbours.

Climate Twins

2004 to 2024 against 1961 to 1990

Over 2004 to 2024, Castle Rock had a mean temperature of 10.4 C (50.6 F) and 433.0 mm (17.0 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Grenville (United States, 329 km away), Pioche (United States, 848 km away) and Show Low AP (United States, 731 km away).

Climate twins of Castle Rock: stations whose 1961 to 1990 climate is closest to its 2004 to 2024 climate
Twin station	Country	Distance away	Mean temperature, 1961-1990	Rain a year, 1961-1990	Climate difference
Grenville	United States	329 km (204 mi)	10.2 C (50.3 F)	412.7 mm (16.2 in)	0.79
Pioche	United States	848 km (527 mi)	10.4 C (50.6 F)	346.4 mm (13.6 in)	0.82
Show Low AP	United States	731 km (454 mi)	10.4 C (50.8 F)	454.3 mm (17.9 in)	0.82

Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.

Download the Data

Data for Castle Rock standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Castle Rock 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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-12. Last revised 12 October 2026 (2026-10-12).