Donnellson Weather Records (USC00132299)

Record envelope, standing records and threshold days for Donnellson (USC00132299), Iowa, United States, with 89 years of record.

Key Facts for Donnellson

Donnellson (USC00132299) is a weather station in Iowa, United States at 40.65 latitude and -91.56 longitude, 215 m (705 ft) above sea level.
The station reports from 1938 to 2026, 89 years of record.
1,464 records set at Donnellson still stand.
Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
Donnellson set a daily record precipitation of 45.0 mm (1.8 in) on 16 September 2026 (provisional).

Provisional Records

Records set in the last 60 days are provisional until they clear the revision window.

About the Station

Location: Iowa, United States, 40.65 latitude, -91.56 longitude.
Elevation: 215 m (705 ft).
Period of record: 1938 to 2026, 89 years.
Eligible elements: prcp, snow, snwd.

Daily Record Envelope and 2026

39 days at or beyond a record

The band shows the record high and record low for each calendar day at Donnellson. The lines show the 2026 daily maximum and minimum. 39 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Donnellson, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	18.3 C (64.9 F)	-28.3 C (-18.9 F)	16.7 C (62.1 F)	-23.9 C (-11.0 F)
Feb	25.0 C (77.0 F)	-23.9 C (-11.0 F)	22.8 C (73.0 F)	-17.8 C (0.0 F)
Mar	31.7 C (89.1 F)	-22.8 C (-9.0 F)	31.7 C (89.1 F)	-14.4 C (6.1 F)
Apr	31.7 C (89.1 F)	-13.3 C (8.1 F)	30.0 C (86.0 F)	0.0 C (32.0 F)
May	36.7 C (98.1 F)	0.0 C (32.0 F)	31.7 C (89.1 F)	2.8 C (37.0 F)
Jun	37.8 C (100.0 F)	7.8 C (46.0 F)	32.8 C (91.0 F)	12.2 C (54.0 F)
Jul	41.7 C (107.1 F)	10.0 C (50.0 F)	37.2 C (99.0 F)	13.3 C (55.9 F)
Aug	38.9 C (102.0 F)	7.8 C (46.0 F)	34.4 C (93.9 F)	12.8 C (55.0 F)
Sep	38.9 C (102.0 F)	2.2 C (36.0 F)	37.8 C (100.0 F)	10.0 C (50.0 F)
Oct	34.4 C (93.9 F)	-6.7 C (19.9 F)	30.6 C (87.1 F)	7.8 C (46.0 F)
Nov	27.2 C (81.0 F)	-16.1 C (3.0 F)	n/a	n/a
Dec	23.3 C (73.9 F)	-23.9 C (-11.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Donnellson still stand. 2012 holds the most, with 106.

Standing records at Donnellson by the year they were set
Year set	Standing records
2006	59
2007	75
2008	67
2009	78
2010	50
2011	87
2012	106
2013	88
2014	95
2015	57
2016	61
2017	81
2018	72
2019	54
2020	56
2021	50
2022	64
2023	58
2024	73
2025	66
2026	67

All-Time Record Progression

4 new records

4 all-time records were set at Donnellson between 13 January 1979 and 2 February 2011. Each dot is a new record.

When Donnellson set new all-time records
Date	Kind	Detail
1979-01-13	Record snow depth	Record snow depth 53.3 cm (21.0 in)
1979-01-14	Record snow depth	Record snow depth 71.1 cm (28.0 in)
1985-01-01	Record daily snowfall	Record daily snowfall 27.9 cm (11.0 in)
2011-02-02	Record daily snowfall	Record daily snowfall 35.6 cm (14.0 in)

Wettest Day of Each Month

Aug: 168.9 mm (6.6 in)

The wettest day on record for each calendar month at Donnellson. The most was 168.9 mm (6.6 in) on 5 August 1970.

Record daily precipitation for each month at Donnellson
Month	Record daily precipitation (mm)	Date
Jan	58.7 mm (2.3 in)	24 January 1938
Feb	53.1 mm (2.1 in)	21 February 1997
Mar	73.2 mm (2.9 in)	4 March 1985
Apr	118.6 mm (4.7 in)	24 April 1976
May	82.0 mm (3.2 in)	27 May 1996
Jun	114.6 mm (4.5 in)	18 June 1946
Jul	94.5 mm (3.7 in)	26 July 2025
Aug	168.9 mm (6.6 in)	5 August 1970
Sep	124.7 mm (4.9 in)	13 September 2008
Oct	79.5 mm (3.1 in)	13 October 1966
Nov	77.2 mm (3.0 in)	1 November 1984
Dec	74.2 mm (2.9 in)	2 December 1982

Period of Record Coverage

2006 to 2026

21 years of record at Donnellson, 2006 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 2006, 2026.

Days with data per year at Donnellson
Year	Days with data	Share of year	Complete
2006	244	67%	No
2007	365	100%	Yes
2008	366	100%	Yes
2009	364	100%	Yes
2010	365	100%	Yes
2011	365	100%	Yes
2012	366	100%	Yes
2013	365	100%	Yes
2014	365	100%	Yes
2015	365	100%	Yes
2016	366	100%	Yes
2017	364	100%	Yes
2018	363	99%	Yes
2019	365	100%	Yes
2020	366	100%	Yes
2021	365	100%	Yes
2022	364	100%	Yes
2023	364	100%	Yes
2024	365	100%	Yes
2025	364	100%	Yes
2026	284	78%	No

Latest Records

Latest records at Donnellson
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
16 September 2026	Donnellson, US	daily rain (Provisional)	45.0 mm (1.8 in)	7.4 mm (0.29 in)	43 years	24 of 100 (Routine)
15 August 2026	Donnellson, US	daily rain	58.7 mm (2.3 in)	10.9 mm (0.4 in)	73 years	36 of 100 (Notable)
18 March 2026	Donnellson, US	daily snow depth	5.1 cm (2.0 in)	2.6 cm (1.0 in)	37 years	20 of 100 (Routine)
12 December 2025	Donnellson, US	daily snowfall	8.4 cm (3.3 in)	0.8 cm (0.3 in)	62 years	28 of 100 (Routine)
3 December 2025	Donnellson, US	daily snow depth (Tie)	15.2 cm (6.0 in)	tie	48 years	5 of 100 (Routine)
2 December 2025	Donnellson, US	daily snow depth (Tie)	15.2 cm (6.0 in)	tie	19 years	3 of 100 (Routine)
29 November 2025	Donnellson, US	daily snowfall (Tie)	12.7 cm (5.0 in)	tie	56 years	6 of 100 (Routine)
26 July 2025	Donnellson, US	monthly rain	94.5 mm (3.7 in)	5.3 mm (0.21 in)	29 years	29 of 100 (Routine)
12 July 2025	Donnellson, US	daily rain	68.8 mm (2.7 in)	10.9 mm (0.4 in)	10 years	18 of 100 (Routine)
20 May 2025	Donnellson, US	daily rain	46.0 mm (1.8 in)	20.6 mm (0.8 in)	40 years	36 of 100 (Notable)
21 April 2025	Donnellson, US	daily rain	48.5 mm (1.9 in)	0.2 mm (0.01 in)	52 years	23 of 100 (Routine)
31 July 2024	Donnellson, US	daily rain	50.3 mm (2.0 in)	2.8 mm (0.11 in)	47 years	23 of 100 (Routine)
29 July 2024	Donnellson, US	daily rain	48.3 mm (1.9 in)	13.2 mm (0.5 in)	38 years	27 of 100 (Routine)
28 April 2024	Donnellson, US	daily rain	51.6 mm (2.0 in)	8.9 mm (0.35 in)	10 years	18 of 100 (Routine)
27 April 2024	Donnellson, US	daily rain	28.4 mm (1.1 in)	7.6 mm (0.30 in)	35 years	24 of 100 (Routine)
14 March 2024	Donnellson, US	daily rain	56.6 mm (2.2 in)	11.1 mm (0.4 in)	80 years	43 of 100 (Notable)
26 January 2024	Donnellson, US	daily rain	20.1 mm (0.8 in)	1.3 mm (0.05 in)	61 years	20 of 100 (Routine)
22 January 2024	Donnellson, US	daily snow depth (Tie)	27.9 cm (11.0 in)	tie	4 years	2 of 100 (Routine)
21 January 2024	Donnellson, US	daily snow depth	30.5 cm (12.0 in)	2.6 cm (1.0 in)	4 years	12 of 100 (Routine)
20 January 2024	Donnellson, US	daily snow depth	30.5 cm (12.0 in)	2.6 cm (1.0 in)	4 years	12 of 100 (Routine)

Climate Trend

19 complete years, 2007 to 2025

One stripe for each of 19 complete years at Donnellson, 2007 to 2025. Blue stripes are years cooler than the station's own mean of 11.2 C (52.1 F); red stripes are warmer. The coolest year was 2014, at 9.3 C (48.7 F), and the warmest was 2012, at 12.8 C (55.0 F). The strongest colour marks a difference of 1.9 C (3.4 F).

Annual mean temperature at Donnellson as warming stripes, 2007 to 2025
Year	Annual mean temperature	Difference from the station mean
2007	11.4 C	+0.22 C
2008	9.7 C	-1.44 C
2009	10.0 C	-1.16 C
2010	10.8 C	-0.36 C
2011	11.2 C	+0.03 C
2012	12.8 C	+1.64 C
2013	10.2 C	-0.95 C
2014	9.3 C	-1.87 C
2015	11.5 C	+0.36 C
2016	12.4 C	+1.21 C
2017	12.0 C	+0.80 C
2018	10.8 C	-0.39 C
2019	10.7 C	-0.49 C
2020	11.4 C	+0.23 C
2021	11.6 C	+0.48 C
2022	10.3 C	-0.83 C
2023	12.1 C	+0.91 C
2024	12.4 C	+1.19 C
2025	11.5 C	+0.35 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

1938 to 2026

Yearly extremes at Donnellson: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	41.7 C (107.1 F)	2012	36.7 C (98.1 F)	21
Coldest night (TNn)	-28.3 C (-18.9 F)	2024	-23.3 C (-9.9 F)	21
Wettest day (Rx1day)	168.9 mm (6.6 in)	1970	64.8 mm (2.6 in)	88
Wettest five days (Rx5day)	233.4 mm (9.2 in)	1970	96.1 mm (3.8 in)	86
Longest dry spell (CDD)	42 days	2013	22 days	86

Hottest day (TXx)

The hottest day of the year at Donnellson, 1938 to 2026. The record is 41.7 C (107.1 F) in 2012, marked on the chart; the median year is 36.7 C (98.1 F).

Hottest day (TXx) at Donnellson by year
Year	Hottest day (TXx)
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	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
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	n/a
1965	n/a
1966	n/a
1967	n/a
1968	n/a
1969	n/a
1970	n/a
1971	n/a
1972	n/a
1973	n/a
1974	n/a
1975	n/a
1976	n/a
1977	n/a
1978	n/a
1979	n/a
1980	n/a
1981	n/a
1982	n/a
1983	n/a
1984	n/a
1985	n/a
1986	n/a
1987	n/a
1988	n/a
1989	n/a
1990	n/a
1991	n/a
1992	n/a
1993	n/a
1994	n/a
1995	n/a
1996	n/a
1997	n/a
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a
2005	n/a
2006	38.3 C (100.9 F)
2007	37.8 C (100.0 F)
2008	35.0 C (95.0 F)
2009	36.7 C (98.1 F)
2010	35.6 C (96.1 F)
2011	38.3 C (100.9 F)
2012	41.7 C (107.1 F)
2013	38.9 C (102.0 F)
2014	35.0 C (95.0 F)
2015	35.0 C (95.0 F)
2016	36.7 C (98.1 F)
2017	37.2 C (99.0 F)
2018	36.7 C (98.1 F)
2019	35.6 C (96.1 F)
2020	35.6 C (96.1 F)
2021	35.0 C (95.0 F)
2022	37.8 C (100.0 F)
2023	37.8 C (100.0 F)
2024	36.1 C (97.0 F)
2025	36.1 C (97.0 F)
2026	37.8 C (100.0 F)

Coldest night (TNn)

The coldest night of the year at Donnellson, 1938 to 2026. The record is -28.3 C (-18.9 F) in 2024, marked on the chart; the median year is -23.3 C (-9.9 F).

Coldest night (TNn) at Donnellson by year
Year	Coldest night (TNn)
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	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
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	n/a
1965	n/a
1966	n/a
1967	n/a
1968	n/a
1969	n/a
1970	n/a
1971	n/a
1972	n/a
1973	n/a
1974	n/a
1975	n/a
1976	n/a
1977	n/a
1978	n/a
1979	n/a
1980	n/a
1981	n/a
1982	n/a
1983	n/a
1984	n/a
1985	n/a
1986	n/a
1987	n/a
1988	n/a
1989	n/a
1990	n/a
1991	n/a
1992	n/a
1993	n/a
1994	n/a
1995	n/a
1996	n/a
1997	n/a
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a
2005	n/a
2006	-15.6 C (3.9 F)
2007	-20.6 C (-5.1 F)
2008	-21.1 C (-6.0 F)
2009	-26.1 C (-15.0 F)
2010	-23.9 C (-11.0 F)
2011	-22.2 C (-8.0 F)
2012	-15.0 C (5.0 F)
2013	-23.3 C (-9.9 F)
2014	-25.0 C (-13.0 F)
2015	-22.8 C (-9.0 F)
2016	-23.3 C (-9.9 F)
2017	-23.3 C (-9.9 F)
2018	-26.7 C (-16.1 F)
2019	-27.8 C (-18.0 F)
2020	-22.2 C (-8.0 F)
2021	-22.8 C (-9.0 F)
2022	-23.9 C (-11.0 F)
2023	-18.3 C (-0.9 F)
2024	-28.3 C (-18.9 F)
2025	-24.4 C (-11.9 F)
2026	-23.9 C (-11.0 F)

Wettest day (Rx1day)

The wettest day of the year at Donnellson, 1938 to 2026. The record is 168.9 mm (6.6 in) in 1970, marked on the chart; the median year is 64.8 mm (2.6 in).

Wettest day (Rx1day) at Donnellson by year
Year	Wettest day (Rx1day)
1938	58.7 mm (2.3 in)
1939	47.8 mm (1.9 in)
1940	54.6 mm (2.1 in)
1941	81.8 mm (3.2 in)
1942	45.5 mm (1.8 in)
1943	46.2 mm (1.8 in)
1944	69.9 mm (2.8 in)
1945	65.0 mm (2.6 in)
1946	114.6 mm (4.5 in)
1947	10.4 mm (0.4 in)
1949	48.5 mm (1.9 in)
1950	70.6 mm (2.8 in)
1951	67.1 mm (2.6 in)
1952	65.0 mm (2.6 in)
1953	33.8 mm (1.3 in)
1954	67.8 mm (2.7 in)
1955	42.4 mm (1.7 in)
1956	50.8 mm (2.0 in)
1957	63.8 mm (2.5 in)
1958	45.7 mm (1.8 in)
1959	82.0 mm (3.2 in)
1960	64.8 mm (2.6 in)
1961	119.4 mm (4.7 in)
1962	44.2 mm (1.7 in)
1963	52.1 mm (2.1 in)
1964	71.6 mm (2.8 in)
1965	51.6 mm (2.0 in)
1966	79.5 mm (3.1 in)
1967	53.3 mm (2.1 in)
1968	66.0 mm (2.6 in)
1969	50.0 mm (2.0 in)
1970	168.9 mm (6.6 in)
1971	61.0 mm (2.4 in)
1972	53.1 mm (2.1 in)
1973	74.4 mm (2.9 in)
1974	45.7 mm (1.8 in)
1975	37.8 mm (1.5 in)
1976	118.6 mm (4.7 in)
1977	48.0 mm (1.9 in)
1978	72.6 mm (2.9 in)
1979	63.5 mm (2.5 in)
1980	102.1 mm (4.0 in)
1981	68.3 mm (2.7 in)
1982	74.2 mm (2.9 in)
1983	72.4 mm (2.9 in)
1984	77.2 mm (3.0 in)
1985	73.2 mm (2.9 in)
1986	63.5 mm (2.5 in)
1987	38.4 mm (1.5 in)
1988	51.8 mm (2.0 in)
1989	41.7 mm (1.6 in)
1990	79.2 mm (3.1 in)
1991	54.1 mm (2.1 in)
1992	56.1 mm (2.2 in)
1993	87.4 mm (3.4 in)
1994	47.5 mm (1.9 in)
1995	64.8 mm (2.6 in)
1996	89.2 mm (3.5 in)
1997	73.7 mm (2.9 in)
1998	66.0 mm (2.6 in)
1999	86.4 mm (3.4 in)
2000	48.0 mm (1.9 in)
2001	47.5 mm (1.9 in)
2002	93.5 mm (3.7 in)
2003	89.2 mm (3.5 in)
2004	90.7 mm (3.6 in)
2005	35.8 mm (1.4 in)
2006	40.9 mm (1.6 in)
2007	114.8 mm (4.5 in)
2008	124.7 mm (4.9 in)
2009	77.5 mm (3.1 in)
2010	85.9 mm (3.4 in)
2011	56.1 mm (2.2 in)
2012	51.8 mm (2.0 in)
2013	75.2 mm (3.0 in)
2014	78.7 mm (3.1 in)
2015	57.9 mm (2.3 in)
2016	72.6 mm (2.9 in)
2017	46.0 mm (1.8 in)
2018	92.5 mm (3.6 in)
2019	81.5 mm (3.2 in)
2020	50.5 mm (2.0 in)
2021	48.3 mm (1.9 in)
2022	46.7 mm (1.8 in)
2023	87.1 mm (3.4 in)
2024	56.6 mm (2.2 in)
2025	94.5 mm (3.7 in)
2026	58.7 mm (2.3 in)

Wettest five days (Rx5day)

The wettest five days of the year at Donnellson, 1938 to 2026. The record is 233.4 mm (9.2 in) in 1970, marked on the chart; the median year is 96.1 mm (3.8 in).

Wettest five days (Rx5day) at Donnellson by year
Year	Wettest five days (Rx5day)
1938	61.8 mm (2.4 in)
1939	n/a
1940	n/a
1941	163.3 mm (6.4 in)
1942	61.8 mm (2.4 in)
1943	68.8 mm (2.7 in)
1944	163.6 mm (6.4 in)
1945	99.3 mm (3.9 in)
1946	190.3 mm (7.5 in)
1947	19.0 mm (0.7 in)
1949	57.4 mm (2.3 in)
1950	129.0 mm (5.1 in)
1951	94.3 mm (3.7 in)
1952	87.1 mm (3.4 in)
1953	63.0 mm (2.5 in)
1954	93.8 mm (3.7 in)
1955	75.0 mm (3.0 in)
1956	71.9 mm (2.8 in)
1957	81.1 mm (3.2 in)
1958	95.0 mm (3.7 in)
1959	122.7 mm (4.8 in)
1960	99.3 mm (3.9 in)
1961	191.5 mm (7.5 in)
1962	74.4 mm (2.9 in)
1963	74.2 mm (2.9 in)
1964	104.6 mm (4.1 in)
1965	124.5 mm (4.9 in)
1966	95.5 mm (3.8 in)
1967	76.4 mm (3.0 in)
1968	86.6 mm (3.4 in)
1969	128.2 mm (5.0 in)
1970	233.4 mm (9.2 in)
1971	61.4 mm (2.4 in)
1972	75.1 mm (3.0 in)
1973	121.5 mm (4.8 in)
1974	80.0 mm (3.1 in)
1975	66.2 mm (2.6 in)
1976	150.4 mm (5.9 in)
1977	146.8 mm (5.8 in)
1978	93.0 mm (3.7 in)
1979	72.6 mm (2.9 in)
1980	181.9 mm (7.2 in)
1981	129.5 mm (5.1 in)
1982	127.1 mm (5.0 in)
1983	98.1 mm (3.9 in)
1984	112.8 mm (4.4 in)
1985	80.8 mm (3.2 in)
1986	128.1 mm (5.0 in)
1987	59.2 mm (2.3 in)
1988	89.2 mm (3.5 in)
1989	44.2 mm (1.7 in)
1990	159.2 mm (6.3 in)
1991	109.4 mm (4.3 in)
1992	125.9 mm (5.0 in)
1993	127.0 mm (5.0 in)
1994	52.3 mm (2.1 in)
1995	110.0 mm (4.3 in)
1996	141.4 mm (5.6 in)
1997	95.8 mm (3.8 in)
1998	91.4 mm (3.6 in)
1999	116.3 mm (4.6 in)
2000	84.8 mm (3.3 in)
2001	68.1 mm (2.7 in)
2002	137.4 mm (5.4 in)
2003	180.9 mm (7.1 in)
2004	167.0 mm (6.6 in)
2005	50.3 mm (2.0 in)
2006	55.1 mm (2.2 in)
2007	164.6 mm (6.5 in)
2008	183.4 mm (7.2 in)
2009	107.4 mm (4.2 in)
2010	136.7 mm (5.4 in)
2011	87.1 mm (3.4 in)
2012	88.9 mm (3.5 in)
2013	94.0 mm (3.7 in)
2014	89.9 mm (3.5 in)
2015	125.9 mm (5.0 in)
2016	86.1 mm (3.4 in)
2017	77.8 mm (3.1 in)
2018	163.6 mm (6.4 in)
2019	123.0 mm (4.8 in)
2020	83.2 mm (3.3 in)
2021	96.4 mm (3.8 in)
2022	92.2 mm (3.6 in)
2023	161.3 mm (6.4 in)
2024	122.5 mm (4.8 in)
2025	199.4 mm (7.9 in)
2026	123.7 mm (4.9 in)

Longest dry spell (CDD)

The longest dry spell of the year at Donnellson, 1938 to 2026. The record is 42 days in 2013, marked on the chart; the median year is 22 days.

Longest dry spell (CDD) at Donnellson by year
Year	Longest dry spell (CDD)
1938	11 days
1939	n/a
1940	n/a
1941	23 days
1942	28 days
1943	27 days
1944	28 days
1945	18 days
1946	22 days
1947	21 days
1949	17 days
1950	30 days
1951	18 days
1952	33 days
1953	23 days
1954	23 days
1955	29 days
1956	29 days
1957	23 days
1958	27 days
1959	20 days
1960	18 days
1961	16 days
1962	19 days
1963	22 days
1964	35 days
1965	20 days
1966	26 days
1967	29 days
1968	21 days
1969	32 days
1970	20 days
1971	31 days
1972	18 days
1973	15 days
1974	22 days
1975	16 days
1976	26 days
1977	14 days
1978	20 days
1979	35 days
1980	28 days
1981	31 days
1982	13 days
1983	21 days
1984	13 days
1985	23 days
1986	31 days
1987	20 days
1988	37 days
1989	25 days
1990	18 days
1991	22 days
1992	22 days
1993	24 days
1994	21 days
1995	22 days
1996	19 days
1997	17 days
1998	16 days
1999	37 days
2000	18 days
2001	25 days
2002	32 days
2003	16 days
2004	22 days
2005	20 days
2006	19 days
2007	25 days
2008	15 days
2009	24 days
2010	26 days
2011	17 days
2012	16 days
2013	42 days
2014	19 days
2015	31 days
2016	22 days
2017	28 days
2018	21 days
2019	18 days
2020	21 days
2021	17 days
2022	17 days
2023	22 days
2024	23 days
2025	30 days
2026	37 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.

Rainfall Return Levels

79 years, 1943 to 2025

A day with at least 63.8 mm (2.5 in) of rain is expected about once in 2 years. A day with at least 144.3 mm (5.7 in) of rain is expected about once in 100 years.

Rainfall return levels at Donnellson: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	63.8 mm (2.5 in)
5 years	84.0 mm (3.3 in)
10 years	97.9 mm (3.9 in)
25 years	116.1 mm (4.6 in)
50 years	130.1 mm (5.1 in)
100 years	144.3 mm (5.7 in)	Longer than the 79 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, 79 years of values from 1943 to 2025.

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: 168.9 mm (6.6 in) in 1970; 124.7 mm (4.9 in) in 2008; 119.4 mm (4.7 in) in 1961.

Download the Data

Data for Donnellson standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Donnellson 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 2026-10-14. Last revised 14 October 2026 (2026-10-14).