Deerfield Dam Weather Records (USC00392234)

Record envelope, standing records and threshold days for Deerfield Dam (USC00392234), South Dakota, United States, with 47 years of record.

Key Facts for Deerfield Dam

Deerfield Dam (USC00392234) is a weather station in South Dakota, United States at 44.02 latitude and -103.78 longitude, 1,790 m (5,873 ft) above sea level.
The station reports from 1909 to 1955, 47 years of record.
1,464 records set at Deerfield Dam still stand.
Records are tracked for prcp, snow: an element needs 30 years of data to be eligible.
Deerfield Dam tied a daily record snowfall of 2.5 cm (1.0 in) on 12 November 1955.

About the Station

Location: South Dakota, United States, 44.02 latitude, -103.78 longitude.
Elevation: 1,790 m (5,873 ft).
Period of record: 1909 to 1955, 47 years.
Eligible elements: 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 Deerfield Dam. 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 Deerfield Dam, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	12.8 C (55.0 F)	-37.2 C (-35.0 F)	n/a	n/a
Feb	14.4 C (57.9 F)	-33.3 C (-27.9 F)	n/a	n/a
Mar	16.1 C (61.0 F)	-35.0 C (-31.0 F)	n/a	n/a
Apr	23.9 C (75.0 F)	-21.7 C (-7.1 F)	n/a	n/a
May	28.9 C (84.0 F)	-13.9 C (7.0 F)	n/a	n/a
Jun	35.0 C (95.0 F)	-10.0 C (14.0 F)	n/a	n/a
Jul	36.1 C (97.0 F)	-3.3 C (26.1 F)	n/a	n/a
Aug	35.0 C (95.0 F)	-4.4 C (24.1 F)	n/a	n/a
Sep	30.0 C (86.0 F)	-11.7 C (10.9 F)	n/a	n/a
Oct	25.6 C (78.1 F)	-18.3 C (-0.9 F)	n/a	n/a
Nov	18.9 C (66.0 F)	-31.7 C (-25.1 F)	n/a	n/a
Dec	15.6 C (60.1 F)	-31.7 C (-25.1 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Deerfield Dam still stand. 1950 holds the most, with 239.

All-Time Record Progression

1 new records

1 all-time records were set at Deerfield Dam between 22 May 1952 and 22 May 1952. Each dot is a new record.

Wettest Day of Each Month

May: 102.6 mm (4.0 in)

The wettest day on record for each calendar month at Deerfield Dam. The most was 102.6 mm (4.0 in) on 22 May 1952.

Record daily precipitation for each month at Deerfield Dam
Month	Record daily precipitation (mm)	Date
Jan	21.3 mm (0.8 in)	4 January 1949
Feb	17.8 mm (0.7 in)	2 February 1912
Mar	31.0 mm (1.2 in)	1 March 1953
Apr	51.3 mm (2.0 in)	9 April 1943
May	102.6 mm (4.0 in)	22 May 1952
Jun	85.3 mm (3.4 in)	13 June 1921
Jul	55.9 mm (2.2 in)	3 July 1941
Aug	45.2 mm (1.8 in)	2 August 1922
Sep	48.8 mm (1.9 in)	28 September 1923
Oct	40.9 mm (1.6 in)	20 October 1924
Nov	34.3 mm (1.4 in)	5 November 1922
Dec	12.2 mm (0.5 in)	12 December 1937

Period of Record Coverage

1948 to 1955

8 years of record at Deerfield Dam, 1948 to 1955. 1 years have data for under 90 percent of days and are left out of rankings: 1948.

Latest Records

Latest records at Deerfield Dam
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
12 November 1955	Deerfield Dam, US	daily snowfall (Tie)	2.5 cm (1.0 in)	tie	45 years	4 of 100 (Routine)
11 November 1955	Deerfield Dam, US	daily snowfall	17.8 cm (7.0 in)	5.1 cm (2.0 in)	44 years	25 of 100 (Routine)
10 November 1955	Deerfield Dam, US	daily rain	10.2 mm (0.4 in)	4.1 mm (0.16 in)	38 years	20 of 100 (Routine)
24 September 1955	Deerfield Dam, US	daily snowfall	10.2 cm (4.0 in)	6.4 cm (2.5 in)	28 years	24 of 100 (Routine)
28 July 1955	Deerfield Dam, US	daily rain (Tie)	33.0 mm (1.3 in)	tie	26 years	3 of 100 (Routine)
9 June 1955	Deerfield Dam, US	daily snowfall	5.1 cm (2.0 in)	5.1 cm (2.0 in)	44 years	27 of 100 (Routine)
25 May 1955	Deerfield Dam, US	daily rain	13.0 mm (0.5 in)	0.6 mm (0.02 in)	33 years	14 of 100 (Routine)
17 May 1955	Deerfield Dam, US	daily rain	27.2 mm (1.1 in)	15.8 mm (0.6 in)	28 years	30 of 100 (Routine)
11 April 1955	Deerfield Dam, US	daily rain	6.4 mm (0.25 in)	1.8 mm (0.07 in)	24 years	13 of 100 (Routine)
11 April 1955	Deerfield Dam, US	daily snowfall	5.1 cm (2.0 in)	1.3 cm (0.5 in)	28 years	13 of 100 (Routine)
4 April 1955	Deerfield Dam, US	daily snowfall	15.2 cm (6.0 in)	3.8 cm (1.5 in)	20 years	15 of 100 (Routine)
4 April 1955	Deerfield Dam, US	daily rain	11.4 mm (0.4 in)	0.7 mm (0.03 in)	20 years	11 of 100 (Routine)
20 March 1955	Deerfield Dam, US	daily snowfall	10.2 cm (4.0 in)	2.6 cm (1.0 in)	22 years	14 of 100 (Routine)
18 February 1955	Deerfield Dam, US	daily rain	3.8 mm (0.15 in)	0.2 mm (0.01 in)	1 year	4 of 100 (Routine)
18 February 1955	Deerfield Dam, US	daily snowfall (Tie)	7.6 cm (3.0 in)	tie	1 year	1 of 100 (Routine)
3 February 1955	Deerfield Dam, US	daily rain	6.4 mm (0.25 in)	2.8 mm (0.11 in)	31 years	20 of 100 (Routine)
3 February 1955	Deerfield Dam, US	daily snowfall	10.2 cm (4.0 in)	2.6 cm (1.0 in)	11 years	13 of 100 (Routine)
30 November 1954	Deerfield Dam, US	daily snowfall (Tie)	10.2 cm (4.0 in)	tie	24 years	2 of 100 (Routine)
26 October 1954	Deerfield Dam, US	daily snowfall	15.2 cm (6.0 in)	7.6 cm (3.0 in)	31 years	29 of 100 (Routine)
26 October 1954	Deerfield Dam, US	daily rain	11.7 mm (0.5 in)	6.1 mm (0.24 in)	44 years	20 of 100 (Routine)

Extremes by Year

1909 to 1955

Yearly extremes at Deerfield Dam: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	36.1 C (97.0 F)	1954	32.5 C (90.5 F)	8
Coldest night (TNn)	-37.2 C (-35.0 F)	1949	-32.8 C (-27.0 F)	8
Wettest day (Rx1day)	102.6 mm (4.0 in)	1952	38.6 mm (1.5 in)	47
Wettest five days (Rx5day)	140.5 mm (5.5 in)	1952	54.1 mm (2.1 in)	47
Longest dry spell (CDD)	68 days	1937	32 days	47

Hottest day (TXx)

The hottest day of the year at Deerfield Dam, 1909 to 1955. The record is 36.1 C (97.0 F) in 1954, marked on the chart; the median year is 32.5 C (90.5 F).

Hottest day (TXx) at Deerfield Dam by year
Year	Hottest day (TXx)
1909	n/a
1910	n/a
1911	n/a
1912	n/a
1913	n/a
1914	n/a
1915	n/a
1916	n/a
1917	n/a
1918	n/a
1919	n/a
1920	n/a
1921	n/a
1922	n/a
1923	n/a
1924	n/a
1925	n/a
1926	n/a
1927	n/a
1928	n/a
1929	n/a
1930	n/a
1931	n/a
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
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
1948	10.6 C (51.1 F)
1949	35.0 C (95.0 F)
1950	31.7 C (89.1 F)
1951	32.8 C (91.0 F)
1952	33.3 C (91.9 F)
1953	31.1 C (88.0 F)
1954	36.1 C (97.0 F)
1955	32.2 C (90.0 F)

Coldest night (TNn)

The coldest night of the year at Deerfield Dam, 1909 to 1955. The record is -37.2 C (-35.0 F) in 1949, marked on the chart; the median year is -32.8 C (-27.0 F).

Coldest night (TNn) at Deerfield Dam by year
Year	Coldest night (TNn)
1909	n/a
1910	n/a
1911	n/a
1912	n/a
1913	n/a
1914	n/a
1915	n/a
1916	n/a
1917	n/a
1918	n/a
1919	n/a
1920	n/a
1921	n/a
1922	n/a
1923	n/a
1924	n/a
1925	n/a
1926	n/a
1927	n/a
1928	n/a
1929	n/a
1930	n/a
1931	n/a
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
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
1948	-27.2 C (-17.0 F)
1949	-37.2 C (-35.0 F)
1950	-35.0 C (-31.0 F)
1951	-36.1 C (-33.0 F)
1952	-31.7 C (-25.1 F)
1953	-30.0 C (-22.0 F)
1954	-31.7 C (-25.1 F)
1955	-33.9 C (-29.0 F)

Wettest day (Rx1day)

The wettest day of the year at Deerfield Dam, 1909 to 1955. The record is 102.6 mm (4.0 in) in 1952, marked on the chart; the median year is 38.6 mm (1.5 in).

Wettest day (Rx1day) at Deerfield Dam by year
Year	Wettest day (Rx1day)
1909	16.5 mm (0.6 in)
1910	19.1 mm (0.8 in)
1911	18.8 mm (0.7 in)
1912	27.4 mm (1.1 in)
1913	34.3 mm (1.4 in)
1914	44.2 mm (1.7 in)
1915	41.1 mm (1.6 in)
1916	25.4 mm (1.0 in)
1917	31.0 mm (1.2 in)
1918	34.3 mm (1.4 in)
1919	48.5 mm (1.9 in)
1920	31.5 mm (1.2 in)
1921	85.3 mm (3.4 in)
1922	45.2 mm (1.8 in)
1923	48.8 mm (1.9 in)
1924	40.9 mm (1.6 in)
1925	44.2 mm (1.7 in)
1926	31.2 mm (1.2 in)
1927	44.2 mm (1.7 in)
1928	40.1 mm (1.6 in)
1929	55.1 mm (2.2 in)
1930	38.6 mm (1.5 in)
1931	16.8 mm (0.7 in)
1932	48.5 mm (1.9 in)
1933	61.0 mm (2.4 in)
1934	23.4 mm (0.9 in)
1935	50.0 mm (2.0 in)
1936	22.6 mm (0.9 in)
1937	30.2 mm (1.2 in)
1938	30.2 mm (1.2 in)
1939	40.1 mm (1.6 in)
1940	34.0 mm (1.3 in)
1941	55.9 mm (2.2 in)
1942	27.2 mm (1.1 in)
1943	52.8 mm (2.1 in)
1944	26.9 mm (1.1 in)
1945	18.8 mm (0.7 in)
1946	39.4 mm (1.6 in)
1947	18.8 mm (0.7 in)
1948	23.6 mm (0.9 in)
1949	47.0 mm (1.9 in)
1950	39.4 mm (1.6 in)
1951	27.7 mm (1.1 in)
1952	102.6 mm (4.0 in)
1953	31.0 mm (1.2 in)
1954	40.1 mm (1.6 in)
1955	41.4 mm (1.6 in)

Wettest five days (Rx5day)

The wettest five days of the year at Deerfield Dam, 1909 to 1955. The record is 140.5 mm (5.5 in) in 1952, marked on the chart; the median year is 54.1 mm (2.1 in).

Wettest five days (Rx5day) at Deerfield Dam by year
Year	Wettest five days (Rx5day)
1909	38.1 mm (1.5 in)
1910	25.9 mm (1.0 in)
1911	28.9 mm (1.1 in)
1912	33.0 mm (1.3 in)
1913	46.5 mm (1.8 in)
1914	71.8 mm (2.8 in)
1915	71.3 mm (2.8 in)
1916	49.0 mm (1.9 in)
1917	48.8 mm (1.9 in)
1918	82.9 mm (3.3 in)
1919	59.9 mm (2.4 in)
1920	54.1 mm (2.1 in)
1921	137.9 mm (5.4 in)
1922	104.7 mm (4.1 in)
1923	74.2 mm (2.9 in)
1924	43.9 mm (1.7 in)
1925	69.8 mm (2.7 in)
1926	74.4 mm (2.9 in)
1927	75.3 mm (3.0 in)
1928	60.5 mm (2.4 in)
1929	80.0 mm (3.1 in)
1930	63.5 mm (2.5 in)
1931	34.0 mm (1.3 in)
1932	71.9 mm (2.8 in)
1933	85.6 mm (3.4 in)
1934	40.9 mm (1.6 in)
1935	59.5 mm (2.3 in)
1936	45.7 mm (1.8 in)
1937	48.6 mm (1.9 in)
1938	35.2 mm (1.4 in)
1939	61.2 mm (2.4 in)
1940	36.6 mm (1.4 in)
1941	70.1 mm (2.8 in)
1942	49.3 mm (1.9 in)
1943	89.1 mm (3.5 in)
1944	42.1 mm (1.7 in)
1945	19.1 mm (0.8 in)
1946	49.1 mm (1.9 in)
1947	30.0 mm (1.2 in)
1948	52.5 mm (2.1 in)
1949	74.7 mm (2.9 in)
1950	54.7 mm (2.2 in)
1951	59.2 mm (2.3 in)
1952	140.5 mm (5.5 in)
1953	40.9 mm (1.6 in)
1954	45.9 mm (1.8 in)
1955	54.1 mm (2.1 in)

Longest dry spell (CDD)

The longest dry spell of the year at Deerfield Dam, 1909 to 1955. The record is 68 days in 1937, marked on the chart; the median year is 32 days.

Longest dry spell (CDD) at Deerfield Dam by year
Year	Longest dry spell (CDD)
1909	35 days
1910	38 days
1911	27 days
1912	21 days
1913	31 days
1914	45 days
1915	20 days
1916	25 days
1917	33 days
1918	24 days
1919	28 days
1920	25 days
1921	48 days
1922	32 days
1923	44 days
1924	15 days
1925	51 days
1926	26 days
1927	24 days
1928	24 days
1929	16 days
1930	38 days
1931	28 days
1932	21 days
1933	49 days
1934	34 days
1935	33 days
1936	38 days
1937	68 days
1938	46 days
1939	57 days
1940	36 days
1941	35 days
1942	46 days
1943	54 days
1944	26 days
1945	25 days
1946	32 days
1947	15 days
1948	36 days
1949	34 days
1950	29 days
1951	30 days
1952	37 days
1953	29 days
1954	31 days
1955	21 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

39 years, 1910 to 1955

A day with at least 37.1 mm (1.5 in) of rain is expected about once in 2 years. A day with at least 95.3 mm (3.8 in) of rain is expected about once in 100 years.

Rainfall return levels at Deerfield Dam: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	37.1 mm (1.5 in)
5 years	51.4 mm (2.0 in)
10 years	61.4 mm (2.4 in)
25 years	74.6 mm (2.9 in)
50 years	84.8 mm (3.3 in)	Longer than the 39 years of record
100 years	95.3 mm (3.8 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 1910 to 1955.

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: 102.6 mm (4.0 in) in 1952; 85.3 mm (3.4 in) in 1921; 61.0 mm (2.4 in) in 1933.

Download the Data

Data for Deerfield Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Deerfield Dam 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).

Year	Days with data	Share of year	Complete
1948	52	14%	No
1949	365	100%	Yes
1950	363	99%	Yes
1951	364	100%	Yes
1952	366	100%	Yes
1953	364	100%	Yes
1954	365	100%	Yes
1955	333	91%	Yes