Rison Weather Records (USC00036174)

Record envelope, standing records and threshold days for Rison (USC00036174), Arkansas, United States, with 128 years of record.

Key Facts for Rison

Rison (USC00036174) is a weather station in Arkansas, United States at 33.95 latitude and -92.20 longitude, 85 m (280 ft) above sea level.
The station reports from 1893 to 2020, 128 years of record.
1,464 records set at Rison still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Rison tied a daily record low minimum temperature of -7.2 C (19.0 F) on 21 February 2020.

About the Station

Location: Arkansas, United States, 33.95 latitude, -92.20 longitude.
Elevation: 85 m (280 ft).
Period of record: 1893 to 2020, 128 years.
Eligible elements: tmax, tmin, prcp, snow.

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 Rison. 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 Rison, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	26.7 C (80.1 F)	-20.0 C (-4.0 F)	n/a	n/a
Feb	28.3 C (82.9 F)	-23.9 C (-11.0 F)	n/a	n/a
Mar	33.3 C (91.9 F)	-10.0 C (14.0 F)	n/a	n/a
Apr	35.0 C (95.0 F)	-3.3 C (26.1 F)	n/a	n/a
May	37.8 C (100.0 F)	-0.6 C (30.9 F)	n/a	n/a
Jun	40.6 C (105.1 F)	5.0 C (41.0 F)	n/a	n/a
Jul	46.1 C (115.0 F)	8.9 C (48.0 F)	n/a	n/a
Aug	43.3 C (109.9 F)	9.4 C (48.9 F)	n/a	n/a
Sep	42.8 C (109.0 F)	2.8 C (37.0 F)	n/a	n/a
Oct	37.2 C (99.0 F)	-3.3 C (26.1 F)	n/a	n/a
Nov	32.2 C (90.0 F)	-13.3 C (8.1 F)	n/a	n/a
Dec	27.2 C (81.0 F)	-15.6 C (3.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Rison still stand. 1902 holds the most, with 60.

Standing records at Rison by the year they were set
Year set	Standing records
1893	18
1894	43
1895	37
1896	56
1897	39
1898	34
1899	45
1900	28
1901	45
1902	60
1903	56
1904	27
1905	7
1906	25
1907	6
1919	18
1920	30
1921	45
1922	33
1923	25
1924	48
1925	49
1926	26
1927	27
1928	16
1929	26
1930	44
1931	20
1932	41
1933	39
1934	12
1935	9
2001	9
2002	12
2003	11
2004	29
2005	16
2006	21
2007	15
2008	26
2009	27
2010	29
2011	35
2012	24
2013	21
2014	37
2015	32
2016	15
2017	28
2018	32
2019	11

All-Time Record Progression

2 new records

2 all-time records were set at Rison between 19 January 1935 and 10 October 2004. Each dot is a new record.

When Rison set new all-time records
Date	Kind	Detail
1935-01-19	Record daily precipitation	Record daily precipitation 183.9 mm (7.2 in)
2004-10-10	Record daily precipitation	Record daily precipitation 199.4 mm (7.9 in)

Wettest Day of Each Month

Oct: 199.4 mm (7.9 in)

The wettest day on record for each calendar month at Rison. The most was 199.4 mm (7.9 in) on 10 October 2004.

Record daily precipitation for each month at Rison
Month	Record daily precipitation (mm)	Date
Jan	183.9 mm (7.2 in)	19 January 1935
Feb	150.4 mm (5.9 in)	20 February 2018
Mar	132.1 mm (5.2 in)	30 March 2016
Apr	139.2 mm (5.5 in)	10 April 1900
May	126.5 mm (5.0 in)	1 May 1958
Jun	143.8 mm (5.7 in)	25 June 1903
Jul	127.0 mm (5.0 in)	4 July 2015
Aug	177.8 mm (7.0 in)	31 August 2012
Sep	139.7 mm (5.5 in)	20 September 2013
Oct	199.4 mm (7.9 in)	10 October 2004
Nov	101.9 mm (4.0 in)	10 November 1952
Dec	146.1 mm (5.8 in)	21 December 2013

Period of Record Coverage

1893 to 2020

52 years of record at Rison, 1893 to 2020. 27 years have data for under 90 percent of days and are left out of rankings: 1893, 1901, 1902, 1903, 1904, 1905, 1906, 1907 and others.

Days with data per year at Rison
Year	Days with data	Share of year	Complete
1893	227	62%	No
1894	364	100%	Yes
1895	364	100%	Yes
1896	337	92%	Yes
1897	344	94%	Yes
1898	363	99%	Yes
1899	333	91%	Yes
1900	365	100%	Yes
1901	273	75%	No
1902	316	87%	No
1903	315	86%	No
1904	211	58%	No
1905	181	50%	No
1906	300	82%	No
1907	9	2%	No
1919	243	67%	No
1920	358	98%	Yes
1921	358	98%	Yes
1922	355	97%	Yes
1923	360	99%	Yes
1924	361	99%	Yes
1925	353	97%	Yes
1926	328	90%	No
1927	325	89%	No
1928	358	98%	Yes
1929	359	98%	Yes
1930	356	98%	Yes
1931	348	95%	Yes
1932	332	91%	Yes
1933	363	99%	Yes
1934	116	32%	No
1935	182	50%	No
2001	181	50%	No
2002	222	61%	No
2003	236	65%	No
2004	266	73%	No
2005	271	74%	No
2006	255	70%	No
2007	301	82%	No
2008	304	83%	No
2009	314	86%	No
2010	341	93%	Yes
2011	313	86%	No
2012	325	89%	No
2013	306	84%	No
2014	365	100%	Yes
2015	365	100%	Yes
2016	366	100%	Yes
2017	365	100%	Yes
2018	365	100%	Yes
2019	295	81%	No
2020	60	16%	No

Latest Records

Latest records at Rison
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
21 February 2020	Rison, US	daily low min (Tie)	-7.2 C (19.0 F)	tie	123 years	10 of 100 (Routine)
12 February 2020	Rison, US	daily rain	127.0 mm (5.0 in)	80.0 mm (3.1 in)	66 years	70 of 100 (Major)
11 February 2020	Rison, US	daily rain	55.9 mm (2.2 in)	6.4 mm (0.25 in)	72 years	34 of 100 (Routine)
2 February 2020	Rison, US	daily high max (Tie)	23.9 C (75.0 F)	tie	96 years	9 of 100 (Routine)
11 January 2020	Rison, US	daily rain	74.7 mm (2.9 in)	29.0 mm (1.1 in)	94 years	53 of 100 (Notable)
9 January 2020	Rison, US	daily high min (Tie)	16.1 C (61.0 F)	tie	121 years	10 of 100 (Routine)
31 October 2019	Rison, US	daily low min	-2.8 C (27.0 F)	0.6 C (1.1 F)	93 years	39 of 100 (Notable)
25 October 2019	Rison, US	daily rain	60.7 mm (2.4 in)	8.6 mm (0.34 in)	113 years	43 of 100 (Notable)
15 October 2019	Rison, US	daily rain	44.5 mm (1.8 in)	1.3 mm (0.05 in)	17 years	15 of 100 (Routine)
7 October 2019	Rison, US	daily low max	13.3 C (55.9 F)	1.1 C (2.0 F)	6 years	14 of 100 (Routine)
29 September 2019	Rison, US	daily high min	22.2 C (72.0 F)	0.5 C (0.9 F)	92 years	38 of 100 (Notable)
28 September 2019	Rison, US	daily high min (Tie)	21.7 C (71.1 F)	tie	93 years	9 of 100 (Routine)
23 September 2019	Rison, US	daily high min	23.3 C (73.9 F)	0.5 C (0.9 F)	118 years	41 of 100 (Notable)
27 August 2019	Rison, US	daily low max (Tie)	27.8 C (82.0 F)	tie	122 years	10 of 100 (Routine)
22 August 2019	Rison, US	daily rain	70.1 mm (2.8 in)	38.1 mm (1.5 in)	100 years	57 of 100 (Notable)
11 August 2019	Rison, US	daily high min	25.6 C (78.1 F)	0.6 C (1.1 F)	4 years	13 of 100 (Routine)
18 July 2019	Rison, US	daily high min (Tie)	23.9 C (75.0 F)	tie	97 years	9 of 100 (Routine)
16 July 2019	Rison, US	daily rain	48.3 mm (1.9 in)	6.1 mm (0.24 in)	0 years	13 of 100 (Routine)
15 July 2019	Rison, US	daily rain	48.3 mm (1.9 in)	20.4 mm (0.8 in)	96 years	48 of 100 (Notable)
15 July 2019	Rison, US	daily low max	25.6 C (78.1 F)	2.2 C (4.0 F)	4 years	17 of 100 (Routine)

Climate Trend

24 complete years, 1894 to 2018

One stripe for each of 24 complete years at Rison, 1894 to 2018. Blue stripes are years cooler than the station's own mean of 17.6 C (63.8 F); red stripes are warmer. The coolest year was 1895, at 15.8 C (60.4 F), and the warmest was 1921, at 19.4 C (66.9 F). The strongest colour marks a difference of 1.9 C (3.4 F).

Annual mean temperature at Rison as warming stripes, 1894 to 2018
Year	Annual mean temperature	Difference from the station mean
1894	16.8 C	-0.83 C
1895	15.8 C	-1.88 C
1897	17.7 C	+0.04 C
1898	17.2 C	-0.44 C
1900	18.3 C	+0.66 C
1920	17.0 C	-0.65 C
1921	19.4 C	+1.76 C
1922	18.2 C	+0.53 C
1923	17.7 C	+0.05 C
1924	17.1 C	-0.54 C
1925	18.7 C	+1.01 C
1928	17.9 C	+0.20 C
1929	18.1 C	+0.43 C
1930	18.2 C	+0.58 C
1931	18.3 C	+0.67 C
1933	18.8 C	+1.19 C
2007	17.8 C	+0.19 C
2009	16.7 C	-1.00 C
2010	17.5 C	-0.16 C
2014	15.8 C	-1.86 C
2015	17.3 C	-0.34 C
2016	18.1 C	+0.40 C
2017	18.0 C	+0.37 C
2018	17.3 C	-0.38 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

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 2020

Yearly extremes at Rison: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	46.1 C (115.0 F)	1930	38.3 C (100.9 F)	52
Coldest night (TNn)	-23.9 C (-11.0 F)	1899	-10.0 C (14.0 F)	52
Wettest day (Rx1day)	199.4 mm (7.9 in)	2004	87.6 mm (3.4 in)	71
Wettest five days (Rx5day)	287.6 mm (11.3 in)	1958	135.1 mm (5.3 in)	71
Longest dry spell (CDD)	55 days	1948	25 days	71

Hottest day (TXx)

The hottest day of the year at Rison, 1893 to 2020. The record is 46.1 C (115.0 F) in 1930, marked on the chart; the median year is 38.3 C (100.9 F).

Hottest day (TXx) at Rison by year
Year	Hottest day (TXx)
1893	38.3 C (100.9 F)
1894	38.9 C (102.0 F)
1895	36.7 C (98.1 F)
1896	42.8 C (109.0 F)
1897	41.1 C (106.0 F)
1898	37.2 C (99.0 F)
1899	38.3 C (100.9 F)
1900	38.3 C (100.9 F)
1901	38.3 C (100.9 F)
1902	40.6 C (105.1 F)
1903	36.1 C (97.0 F)
1904	37.2 C (99.0 F)
1905	38.3 C (100.9 F)
1906	37.2 C (99.0 F)
1907	25.6 C (78.1 F)
1913	n/a
1914	n/a
1915	n/a
1916	n/a
1917	n/a
1918	n/a
1919	40.6 C (105.1 F)
1920	38.9 C (102.0 F)
1921	40.6 C (105.1 F)
1922	40.0 C (104.0 F)
1923	40.0 C (104.0 F)
1924	42.8 C (109.0 F)
1925	42.8 C (109.0 F)
1926	42.2 C (108.0 F)
1927	37.8 C (100.0 F)
1928	39.4 C (102.9 F)
1929	40.0 C (104.0 F)
1930	46.1 C (115.0 F)
1931	40.0 C (104.0 F)
1932	39.4 C (102.9 F)
1933	39.4 C (102.9 F)
1934	32.2 C (90.0 F)
1935	39.4 C (102.9 F)
1947	n/a
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
2001	36.7 C (98.1 F)
2002	35.6 C (96.1 F)
2003	36.7 C (98.1 F)
2004	36.1 C (97.0 F)
2005	38.3 C (100.9 F)
2006	39.4 C (102.9 F)
2007	38.9 C (102.0 F)
2008	39.4 C (102.9 F)
2009	36.7 C (98.1 F)
2010	40.6 C (105.1 F)
2011	41.7 C (107.1 F)
2012	40.0 C (104.0 F)
2013	37.2 C (99.0 F)
2014	35.0 C (95.0 F)
2015	37.8 C (100.0 F)
2016	36.7 C (98.1 F)
2017	35.0 C (95.0 F)
2018	36.7 C (98.1 F)
2019	36.7 C (98.1 F)
2020	23.9 C (75.0 F)

Coldest night (TNn)

The coldest night of the year at Rison, 1893 to 2020. The record is -23.9 C (-11.0 F) in 1899, marked on the chart; the median year is -10.0 C (14.0 F).

Coldest night (TNn) at Rison by year
Year	Coldest night (TNn)
1893	-9.4 C (15.1 F)
1894	-14.4 C (6.1 F)
1895	-17.8 C (0.0 F)
1896	-11.7 C (10.9 F)
1897	-10.0 C (14.0 F)
1898	-10.6 C (12.9 F)
1899	-23.9 C (-11.0 F)
1900	-13.3 C (8.1 F)
1901	-15.6 C (3.9 F)
1902	-10.0 C (14.0 F)
1903	-15.6 C (3.9 F)
1904	-2.2 C (28.0 F)
1905	-7.8 C (18.0 F)
1906	-8.9 C (16.0 F)
1907	3.9 C (39.0 F)
1913	n/a
1914	n/a
1915	n/a
1916	n/a
1917	n/a
1918	n/a
1919	-8.9 C (16.0 F)
1920	-7.8 C (18.0 F)
1921	-6.1 C (21.0 F)
1922	-7.2 C (19.0 F)
1923	-8.9 C (16.0 F)
1924	-13.9 C (7.0 F)
1925	-12.2 C (10.0 F)
1926	-8.9 C (16.0 F)
1927	-10.6 C (12.9 F)
1928	-6.7 C (19.9 F)
1929	-10.6 C (12.9 F)
1930	-20.0 C (-4.0 F)
1931	-7.2 C (19.0 F)
1932	-10.0 C (14.0 F)
1933	-15.0 C (5.0 F)
1934	-9.4 C (15.1 F)
1935	-10.6 C (12.9 F)
1947	n/a
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
2001	-4.4 C (24.1 F)
2002	-10.0 C (14.0 F)
2003	-10.6 C (12.9 F)
2004	-10.6 C (12.9 F)
2005	-10.0 C (14.0 F)
2006	-11.1 C (12.0 F)
2007	-6.7 C (19.9 F)
2008	-9.4 C (15.1 F)
2009	-7.2 C (19.0 F)
2010	-12.2 C (10.0 F)
2011	-11.1 C (12.0 F)
2012	-7.2 C (19.0 F)
2013	-6.1 C (21.0 F)
2014	-12.8 C (9.0 F)
2015	-12.2 C (10.0 F)
2016	-8.9 C (16.0 F)
2017	-11.1 C (12.0 F)
2018	-11.1 C (12.0 F)
2019	-5.6 C (21.9 F)
2020	-7.8 C (18.0 F)

Wettest day (Rx1day)

The wettest day of the year at Rison, 1893 to 2020. The record is 199.4 mm (7.9 in) in 2004, marked on the chart; the median year is 87.6 mm (3.4 in).

Wettest day (Rx1day) at Rison by year
Year	Wettest day (Rx1day)
1893	58.4 mm (2.3 in)
1894	54.9 mm (2.2 in)
1895	66.0 mm (2.6 in)
1896	57.2 mm (2.3 in)
1897	61.0 mm (2.4 in)
1898	76.2 mm (3.0 in)
1899	57.2 mm (2.3 in)
1900	139.2 mm (5.5 in)
1901	65.0 mm (2.6 in)
1902	90.2 mm (3.6 in)
1903	143.8 mm (5.7 in)
1904	73.9 mm (2.9 in)
1905	52.1 mm (2.1 in)
1906	89.7 mm (3.5 in)
1907	15.7 mm (0.6 in)
1913	50.8 mm (2.0 in)
1914	98.6 mm (3.9 in)
1915	42.4 mm (1.7 in)
1916	62.7 mm (2.5 in)
1917	45.5 mm (1.8 in)
1918	68.1 mm (2.7 in)
1919	78.2 mm (3.1 in)
1920	94.0 mm (3.7 in)
1921	96.5 mm (3.8 in)
1922	72.9 mm (2.9 in)
1923	108.5 mm (4.3 in)
1924	59.2 mm (2.3 in)
1925	83.8 mm (3.3 in)
1926	97.8 mm (3.9 in)
1927	101.6 mm (4.0 in)
1928	68.6 mm (2.7 in)
1929	53.3 mm (2.1 in)
1930	101.6 mm (4.0 in)
1931	81.5 mm (3.2 in)
1932	74.9 mm (2.9 in)
1933	121.9 mm (4.8 in)
1934	49.5 mm (1.9 in)
1935	183.9 mm (7.2 in)
1947	135.4 mm (5.3 in)
1948	90.2 mm (3.6 in)
1949	87.6 mm (3.4 in)
1950	74.9 mm (2.9 in)
1951	68.6 mm (2.7 in)
1952	101.9 mm (4.0 in)
1953	84.3 mm (3.3 in)
1954	68.6 mm (2.7 in)
1955	85.9 mm (3.4 in)
1956	79.5 mm (3.1 in)
1957	93.0 mm (3.7 in)
1958	126.5 mm (5.0 in)
1959	32.5 mm (1.3 in)
2001	140.2 mm (5.5 in)
2002	92.7 mm (3.6 in)
2003	92.7 mm (3.6 in)
2004	199.4 mm (7.9 in)
2005	74.9 mm (2.9 in)
2006	68.6 mm (2.7 in)
2007	102.9 mm (4.1 in)
2008	198.1 mm (7.8 in)
2009	118.9 mm (4.7 in)
2010	74.2 mm (2.9 in)
2011	111.8 mm (4.4 in)
2012	177.8 mm (7.0 in)
2013	146.1 mm (5.8 in)
2014	88.9 mm (3.5 in)
2015	127.0 mm (5.0 in)
2016	132.1 mm (5.2 in)
2017	115.3 mm (4.5 in)
2018	150.4 mm (5.9 in)
2019	99.1 mm (3.9 in)
2020	127.0 mm (5.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Rison, 1893 to 2020. The record is 287.6 mm (11.3 in) in 1958, marked on the chart; the median year is 135.1 mm (5.3 in).

Wettest five days (Rx5day) at Rison by year
Year	Wettest five days (Rx5day)
1893	86.4 mm (3.4 in)
1894	187.7 mm (7.4 in)
1895	95.5 mm (3.8 in)
1896	84.3 mm (3.3 in)
1897	152.4 mm (6.0 in)
1898	110.5 mm (4.4 in)
1899	71.1 mm (2.8 in)
1900	150.6 mm (5.9 in)
1901	80.8 mm (3.2 in)
1902	137.4 mm (5.4 in)
1903	175.5 mm (6.9 in)
1904	115.5 mm (4.5 in)
1905	88.7 mm (3.5 in)
1906	135.7 mm (5.3 in)
1907	15.7 mm (0.6 in)
1913	75.7 mm (3.0 in)
1914	110.0 mm (4.3 in)
1915	87.4 mm (3.4 in)
1916	164.8 mm (6.5 in)
1917	90.7 mm (3.6 in)
1918	154.0 mm (6.1 in)
1919	145.1 mm (5.7 in)
1920	129.6 mm (5.1 in)
1921	129.5 mm (5.1 in)
1922	136.1 mm (5.4 in)
1923	118.7 mm (4.7 in)
1924	90.0 mm (3.5 in)
1925	162.6 mm (6.4 in)
1926	135.9 mm (5.4 in)
1927	124.5 mm (4.9 in)
1928	124.8 mm (4.9 in)
1929	63.5 mm (2.5 in)
1930	200.4 mm (7.9 in)
1931	140.7 mm (5.5 in)
1932	102.9 mm (4.1 in)
1933	191.8 mm (7.6 in)
1934	69.8 mm (2.7 in)
1935	183.9 mm (7.2 in)
1947	210.6 mm (8.3 in)
1948	90.2 mm (3.6 in)
1949	116.8 mm (4.6 in)
1950	137.1 mm (5.4 in)
1951	83.8 mm (3.3 in)
1952	101.9 mm (4.0 in)
1953	167.3 mm (6.6 in)
1954	115.4 mm (4.5 in)
1955	134.8 mm (5.3 in)
1956	119.1 mm (4.7 in)
1957	144.6 mm (5.7 in)
1958	287.6 mm (11.3 in)
1959	32.7 mm (1.3 in)
2001	152.4 mm (6.0 in)
2002	136.1 mm (5.4 in)
2003	100.3 mm (3.9 in)
2004	199.4 mm (7.9 in)
2005	74.9 mm (2.9 in)
2006	68.6 mm (2.7 in)
2007	198.9 mm (7.8 in)
2008	198.1 mm (7.8 in)
2009	146.9 mm (5.8 in)
2010	114.8 mm (4.5 in)
2011	144.8 mm (5.7 in)
2012	177.8 mm (7.0 in)
2013	146.1 mm (5.8 in)
2014	115.6 mm (4.6 in)
2015	171.5 mm (6.8 in)
2016	209.6 mm (8.3 in)
2017	135.1 mm (5.3 in)
2018	244.4 mm (9.6 in)
2019	183.0 mm (7.2 in)
2020	215.9 mm (8.5 in)

Longest dry spell (CDD)

The longest dry spell of the year at Rison, 1893 to 2020. The record is 55 days in 1948, marked on the chart; the median year is 25 days.

Longest dry spell (CDD) at Rison by year
Year	Longest dry spell (CDD)
1893	26 days
1894	29 days
1895	32 days
1896	37 days
1897	24 days
1898	18 days
1899	22 days
1900	18 days
1901	24 days
1902	22 days
1903	25 days
1904	27 days
1905	13 days
1906	28 days
1907	4 days
1913	33 days
1914	29 days
1915	24 days
1916	26 days
1917	21 days
1918	31 days
1919	22 days
1920	18 days
1921	29 days
1922	29 days
1923	25 days
1924	38 days
1925	42 days
1926	24 days
1927	30 days
1928	33 days
1929	36 days
1930	39 days
1931	25 days
1932	19 days
1933	16 days
1934	15 days
1935	17 days
1947	52 days
1948	55 days
1949	24 days
1950	19 days
1951	19 days
1952	35 days
1953	27 days
1954	29 days
1955	31 days
1956	25 days
1957	21 days
1958	26 days
1959	9 days
2001	32 days
2002	21 days
2003	26 days
2004	23 days
2005	36 days
2006	22 days
2007	45 days
2008	23 days
2009	18 days
2010	38 days
2011	21 days
2012	22 days
2013	19 days
2014	19 days
2015	29 days
2016	51 days
2017	39 days
2018	22 days
2019	24 days
2020	10 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

24 years with a frost

Across 24 years with a frost, the median last spring frost at Rison falls on 30 March and the median first autumn frost on 5 November, which leaves a median of 218 days between them.

Frost dates and growing season at Rison
Measure	Median, all years	Earliest period	Recent period (1894 to 2018)	Recent against earliest	Fitted trend
Last spring frost	30 March	n/a	30 March	n/a	n/a
First autumn frost	5 November	n/a	5 November	n/a	n/a
Growing days	218 days	n/a	218 days	n/a	n/a

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

39 years, 1894 to 2017

A day with at least 84.7 mm (3.3 in) of rain is expected about once in 2 years. A day with at least 182.8 mm (7.2 in) of rain is expected about once in 100 years.

Rainfall return levels at Rison: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	84.7 mm (3.3 in)
5 years	111.9 mm (4.4 in)
10 years	129.6 mm (5.1 in)
25 years	151.4 mm (6.0 in)
50 years	167.3 mm (6.6 in)	Longer than the 39 years of record
100 years	182.8 mm (7.2 in)	Longer than the 39 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, 39 years of values from 1894 to 2017.

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: 198.1 mm (7.8 in) in 2008; 139.2 mm (5.5 in) in 1900; 132.1 mm (5.2 in) in 2016.

Download the Data

Data for Rison standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Rison 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 2025-12-31. Last revised 31 December 2025 (2025-12-31).