Dahlgren Weapons Lab Weather Records (USW00013760)

Record envelope, standing records and threshold days for Dahlgren Weapons Lab (USW00013760), Virginia, United States, with 42 years of record.

Key Facts for Dahlgren Weapons Lab

Dahlgren Weapons Lab (USW00013760) is a weather station in Virginia, United States at 38.33 latitude and -77.03 longitude, 6 m (20 ft) above sea level.
The station reports from 1920 to 1961, 42 years of record.
1,464 records set at Dahlgren Weapons Lab still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Dahlgren Weapons Lab set a daily record low maximum temperature of 12.2 C (54.0 F) on 28 May 1961.

About the Station

Location: Virginia, United States, 38.33 latitude, -77.03 longitude.
Elevation: 6 m (20 ft).
Period of record: 1920 to 1961, 42 years.
Eligible elements: tmax, tmin, prcp.

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 Dahlgren Weapons Lab. 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 Dahlgren Weapons Lab, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	26.1 C (79.0 F)	-20.0 C (-4.0 F)	n/a	n/a
Feb	30.0 C (86.0 F)	-19.4 C (-2.9 F)	n/a	n/a
Mar	31.7 C (89.1 F)	-10.6 C (12.9 F)	n/a	n/a
Apr	34.4 C (93.9 F)	-6.1 C (21.0 F)	n/a	n/a
May	36.1 C (97.0 F)	1.1 C (34.0 F)	n/a	n/a
Jun	38.3 C (100.9 F)	5.6 C (42.1 F)	n/a	n/a
Jul	41.1 C (106.0 F)	10.0 C (50.0 F)	n/a	n/a
Aug	38.9 C (102.0 F)	10.0 C (50.0 F)	n/a	n/a
Sep	38.9 C (102.0 F)	3.9 C (39.0 F)	n/a	n/a
Oct	36.1 C (97.0 F)	-3.9 C (25.0 F)	n/a	n/a
Nov	28.9 C (84.0 F)	-14.4 C (6.1 F)	n/a	n/a
Dec	25.0 C (77.0 F)	-15.0 C (5.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Dahlgren Weapons Lab still stand. 1930 holds the most, with 66.

Standing records at Dahlgren Weapons Lab by the year they were set
Year set	Standing records
1920	31
1921	31
1922	27
1923	47
1924	36
1925	55
1926	53
1927	50
1928	38
1929	52
1930	66
1931	44
1932	42
1933	39
1934	37
1935	42
1936	38
1937	16
1938	24
1939	35
1940	39
1941	42
1942	33
1943	31
1944	18
1945	38
1946	32
1947	43
1948	25
1949	21
1950	33
1951	28
1952	24
1953	24
1954	45
1955	23
1956	32
1957	29
1958	22
1959	35
1960	27
1961	17

All-Time Record Progression

2 new records

2 all-time records were set at Dahlgren Weapons Lab between 17 February 1958 and 29 January 1961. Each dot is a new record.

When Dahlgren Weapons Lab set new all-time records
Date	Kind	Detail
1958-02-17	Record low maximum temperature	Record low maximum temperature -8.9 C (16.0 F)
1961-01-29	Record low minimum temperature	Record low minimum temperature -20.0 C (-4.0 F)

Wettest Day of Each Month

Sep: 214.9 mm (8.5 in)

The wettest day on record for each calendar month at Dahlgren Weapons Lab. The most was 214.9 mm (8.5 in) on 9 September 1950.

Record daily precipitation for each month at Dahlgren Weapons Lab
Month	Record daily precipitation (mm)	Date
Jan	54.1 mm (2.1 in)	3 January 1944
Feb	43.9 mm (1.7 in)	19 February 1927
Mar	64.3 mm (2.5 in)	20 March 1958
Apr	56.6 mm (2.2 in)	8 April 1940
May	49.5 mm (1.9 in)	26 May 1938
Jun	95.5 mm (3.8 in)	13 June 1947
Jul	109.7 mm (4.3 in)	13 July 1944
Aug	164.1 mm (6.5 in)	12 August 1955
Sep	214.9 mm (8.5 in)	9 September 1950
Oct	100.1 mm (3.9 in)	29 October 1953
Nov	60.2 mm (2.4 in)	16 November 1920
Dec	59.2 mm (2.3 in)	13 December 1941

Period of Record Coverage

1920 to 1961

42 years of record at Dahlgren Weapons Lab, 1920 to 1961. 7 years have data for under 90 percent of days and are left out of rankings: 1920, 1927, 1931, 1936, 1959, 1960, 1961.

Days with data per year at Dahlgren Weapons Lab
Year	Days with data	Share of year	Complete
1920	244	67%	No
1921	364	100%	Yes
1922	364	100%	Yes
1923	364	100%	Yes
1924	365	100%	Yes
1925	361	99%	Yes
1926	365	100%	Yes
1927	315	86%	No
1928	364	99%	Yes
1929	365	100%	Yes
1930	365	100%	Yes
1931	325	89%	No
1932	365	100%	Yes
1933	345	95%	Yes
1934	349	96%	Yes
1935	354	97%	Yes
1936	284	78%	No
1937	365	100%	Yes
1938	364	100%	Yes
1939	363	99%	Yes
1940	365	100%	Yes
1941	355	97%	Yes
1942	362	99%	Yes
1943	358	98%	Yes
1944	355	97%	Yes
1945	361	99%	Yes
1946	364	100%	Yes
1947	362	99%	Yes
1948	363	99%	Yes
1949	362	99%	Yes
1950	363	99%	Yes
1951	364	100%	Yes
1952	364	99%	Yes
1953	363	99%	Yes
1954	363	99%	Yes
1955	363	99%	Yes
1956	365	100%	Yes
1957	345	95%	Yes
1958	364	100%	Yes
1959	318	87%	No
1960	301	82%	No
1961	149	41%	No

Latest Records

Latest records at Dahlgren Weapons Lab
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
28 May 1961	Dahlgren Weapons Lab, US	daily low max	12.2 C (54.0 F)	6.7 C (12.1 F)	35 years	27 of 100 (Routine)
28 May 1961	Dahlgren Weapons Lab, US	daily low min	5.0 C (41.0 F)	0.6 C (1.1 F)	36 years	15 of 100 (Routine)
9 May 1961	Dahlgren Weapons Lab, US	daily high max	31.1 C (88.0 F)	1.7 C (3.1 F)	31 years	16 of 100 (Routine)
26 April 1961	Dahlgren Weapons Lab, US	daily high min	17.2 C (63.0 F)	0.5 C (0.9 F)	22 years	11 of 100 (Routine)
13 April 1961	Dahlgren Weapons Lab, US	daily rain (Tie)	31.5 mm (1.2 in)	tie	8 years	1 of 100 (Routine)
10 April 1961	Dahlgren Weapons Lab, US	daily rain	22.9 mm (0.9 in)	3.8 mm (0.15 in)	24 years	14 of 100 (Routine)
8 April 1961	Dahlgren Weapons Lab, US	daily low min (Tie)	0.0 C (32.0 F)	tie	24 years	2 of 100 (Routine)
3 April 1961	Dahlgren Weapons Lab, US	daily low min	-1.1 C (30.0 F)	0.5 C (0.9 F)	39 years	16 of 100 (Routine)
23 March 1961	Dahlgren Weapons Lab, US	daily rain	23.9 mm (0.9 in)	0.3 mm (0.01 in)	32 years	13 of 100 (Routine)
7 March 1961	Dahlgren Weapons Lab, US	daily high max (Tie)	27.8 C (82.0 F)	tie	40 years	4 of 100 (Routine)
7 March 1961	Dahlgren Weapons Lab, US	daily high min (Tie)	11.1 C (52.0 F)	tie	15 years	2 of 100 (Routine)
6 March 1961	Dahlgren Weapons Lab, US	daily high max	27.2 C (81.0 F)	2.2 C (4.0 F)	15 years	11 of 100 (Routine)
5 March 1961	Dahlgren Weapons Lab, US	daily high max	24.4 C (75.9 F)	1.1 C (2.0 F)	22 years	11 of 100 (Routine)
23 February 1961	Dahlgren Weapons Lab, US	daily rain	24.6 mm (1.0 in)	6.3 mm (0.25 in)	23 years	18 of 100 (Routine)
20 February 1961	Dahlgren Weapons Lab, US	daily high max (Tie)	23.3 C (73.9 F)	tie	22 years	2 of 100 (Routine)
19 February 1961	Dahlgren Weapons Lab, US	daily high min	8.3 C (46.9 F)	1.6 C (2.9 F)	12 years	10 of 100 (Routine)
9 February 1961	Dahlgren Weapons Lab, US	daily rain	25.7 mm (1.0 in)	15.0 mm (0.6 in)	30 years	33 of 100 (Routine)
6 February 1961	Dahlgren Weapons Lab, US	daily low min	-12.2 C (10.0 F)	2.2 C (4.0 F)	14 years	12 of 100 (Routine)
3 February 1961	Dahlgren Weapons Lab, US	daily low min	-13.3 C (8.1 F)	2.7 C (4.9 F)	19 years	14 of 100 (Routine)
3 February 1961	Dahlgren Weapons Lab, US	daily low max	-6.7 C (19.9 F)	0.6 C (1.1 F)	10 years	7 of 100 (Routine)

Climate Trend

34 complete years, 1921 to 1958

One stripe for each of 34 complete years at Dahlgren Weapons Lab, 1921 to 1958. Blue stripes are years cooler than the station's own mean of 13.8 C (56.8 F); red stripes are warmer. The coolest year was 1926, at 12.5 C (54.5 F), and the warmest was 1953, at 14.8 C (58.6 F). The strongest colour marks a difference of 1.4 C (2.5 F).

Annual mean temperature at Dahlgren Weapons Lab as warming stripes, 1921 to 1958
Year	Annual mean temperature	Difference from the station mean
1921	14.3 C	+0.48 C
1922	13.5 C	-0.32 C
1923	13.2 C	-0.61 C
1924	12.5 C	-1.27 C
1925	13.4 C	-0.37 C
1926	12.5 C	-1.31 C
1928	13.0 C	-0.76 C
1929	13.3 C	-0.47 C
1930	13.8 C	-0.01 C
1932	14.4 C	+0.64 C
1933	14.4 C	+0.55 C
1934	13.4 C	-0.45 C
1935	13.3 C	-0.49 C
1937	13.9 C	+0.14 C
1938	14.6 C	+0.77 C
1939	14.5 C	+0.72 C
1940	12.8 C	-1.02 C
1941	14.5 C	+0.70 C
1943	14.2 C	+0.40 C
1944	14.3 C	+0.48 C
1945	13.8 C	-0.03 C
1946	14.4 C	+0.60 C
1947	13.5 C	-0.26 C
1948	13.6 C	-0.25 C
1949	14.7 C	+0.93 C
1950	13.6 C	-0.18 C
1951	13.9 C	+0.13 C
1952	14.2 C	+0.40 C
1953	14.8 C	+0.97 C
1954	14.2 C	+0.38 C
1955	13.9 C	+0.09 C
1956	13.8 C	+0.04 C
1957	14.1 C	+0.34 C
1958	12.7 C	-1.09 C

The annual mean temperature here has risen by 0.19 C (0.00 to 0.38) per decade over 1921 to 1958. In Fahrenheit: 0.34 F (0.00 to 0.68) per decade. The slope is a straight line fitted to 34 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Dahlgren Weapons Lab
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.19 C (0.00 to 0.38) per decade	0.34 F (0.00 to 0.68) per decade	1921 to 1958	34	Rise
Mean daily maximum	0.1 C (-0.1 to 0.3) per decade	0.2 F (-0.2 to 0.5) per decade	1921 to 1958	34	Not clearly different from zero
Mean daily minimum	0.3 C (0.1 to 0.5) per decade	0.5 F (0.1 to 1.0) per decade	1921 to 1958	34	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

1920 to 1961

Yearly extremes at Dahlgren Weapons Lab: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	41.1 C (106.0 F)	1930	36.4 C (97.5 F)	42
Coldest night (TNn)	-20.0 C (-4.0 F)	1961	-12.5 C (9.5 F)	42
Wettest day (Rx1day)	214.9 mm (8.5 in)	1950	56.5 mm (2.2 in)	42
Wettest five days (Rx5day)	305.5 mm (12.0 in)	1935	85.8 mm (3.4 in)	42
Longest dry spell (CDD)	34 days	1941	18 days	42

Hottest day (TXx)

The hottest day of the year at Dahlgren Weapons Lab, 1920 to 1961. The record is 41.1 C (106.0 F) in 1930, marked on the chart; the median year is 36.4 C (97.5 F).

Hottest day (TXx) at Dahlgren Weapons Lab by year
Year	Hottest day (TXx)
1920	35.6 C (96.1 F)
1921	35.6 C (96.1 F)
1922	34.4 C (93.9 F)
1923	37.2 C (99.0 F)
1924	36.7 C (98.1 F)
1925	36.7 C (98.1 F)
1926	36.1 C (97.0 F)
1927	34.4 C (93.9 F)
1928	35.6 C (96.1 F)
1929	36.1 C (97.0 F)
1930	41.1 C (106.0 F)
1931	37.2 C (99.0 F)
1932	37.8 C (100.0 F)
1933	36.1 C (97.0 F)
1934	37.8 C (100.0 F)
1935	36.1 C (97.0 F)
1936	37.8 C (100.0 F)
1937	35.0 C (95.0 F)
1938	35.0 C (95.0 F)
1939	37.2 C (99.0 F)
1940	36.7 C (98.1 F)
1941	36.1 C (97.0 F)
1942	37.2 C (99.0 F)
1943	37.2 C (99.0 F)
1944	36.7 C (98.1 F)
1945	35.6 C (96.1 F)
1946	33.9 C (93.0 F)
1947	36.7 C (98.1 F)
1948	37.8 C (100.0 F)
1949	35.6 C (96.1 F)
1950	35.6 C (96.1 F)
1951	36.7 C (98.1 F)
1952	38.3 C (100.9 F)
1953	38.9 C (102.0 F)
1954	38.9 C (102.0 F)
1955	36.1 C (97.0 F)
1956	35.6 C (96.1 F)
1957	36.7 C (98.1 F)
1958	35.0 C (95.0 F)
1959	38.3 C (100.9 F)
1960	35.6 C (96.1 F)
1961	31.1 C (88.0 F)

Coldest night (TNn)

The coldest night of the year at Dahlgren Weapons Lab, 1920 to 1961. The record is -20.0 C (-4.0 F) in 1961, marked on the chart; the median year is -12.5 C (9.5 F).

Coldest night (TNn) at Dahlgren Weapons Lab by year
Year	Coldest night (TNn)
1920	-8.3 C (17.1 F)
1921	-11.1 C (12.0 F)
1922	-15.0 C (5.0 F)
1923	-10.6 C (12.9 F)
1924	-13.3 C (8.1 F)
1925	-15.6 C (3.9 F)
1926	-14.4 C (6.1 F)
1927	-13.3 C (8.1 F)
1928	-15.6 C (3.9 F)
1929	-12.8 C (9.0 F)
1930	-14.4 C (6.1 F)
1931	-11.7 C (10.9 F)
1932	-9.4 C (15.1 F)
1933	-11.7 C (10.9 F)
1934	-19.4 C (-2.9 F)
1935	-16.1 C (3.0 F)
1936	-16.1 C (3.0 F)
1937	-7.2 C (19.0 F)
1938	-8.3 C (17.1 F)
1939	-8.3 C (17.1 F)
1940	-14.4 C (6.1 F)
1941	-7.2 C (19.0 F)
1942	-14.4 C (6.1 F)
1943	-13.3 C (8.1 F)
1944	-7.8 C (18.0 F)
1945	-10.0 C (14.0 F)
1946	-11.1 C (12.0 F)
1947	-13.3 C (8.1 F)
1948	-13.9 C (7.0 F)
1949	-8.3 C (17.1 F)
1950	-8.9 C (16.0 F)
1951	-10.6 C (12.9 F)
1952	-10.0 C (14.0 F)
1953	-8.9 C (16.0 F)
1954	-10.0 C (14.0 F)
1955	-12.2 C (10.0 F)
1956	-8.3 C (17.1 F)
1957	-15.6 C (3.9 F)
1958	-14.4 C (6.1 F)
1959	-13.3 C (8.1 F)
1960	-12.8 C (9.0 F)
1961	-20.0 C (-4.0 F)

Wettest day (Rx1day)

The wettest day of the year at Dahlgren Weapons Lab, 1920 to 1961. The record is 214.9 mm (8.5 in) in 1950, marked on the chart; the median year is 56.5 mm (2.2 in).

Wettest day (Rx1day) at Dahlgren Weapons Lab by year
Year	Wettest day (Rx1day)
1920	66.3 mm (2.6 in)
1921	53.3 mm (2.1 in)
1922	53.1 mm (2.1 in)
1923	55.6 mm (2.2 in)
1924	71.6 mm (2.8 in)
1925	68.1 mm (2.7 in)
1926	38.1 mm (1.5 in)
1927	47.5 mm (1.9 in)
1928	138.9 mm (5.5 in)
1929	70.4 mm (2.8 in)
1930	39.9 mm (1.6 in)
1931	40.4 mm (1.6 in)
1932	48.3 mm (1.9 in)
1933	68.6 mm (2.7 in)
1934	63.0 mm (2.5 in)
1935	164.3 mm (6.5 in)
1936	47.2 mm (1.9 in)
1937	61.0 mm (2.4 in)
1938	62.0 mm (2.4 in)
1939	42.2 mm (1.7 in)
1940	56.6 mm (2.2 in)
1941	60.7 mm (2.4 in)
1942	51.6 mm (2.0 in)
1943	44.5 mm (1.8 in)
1944	109.7 mm (4.3 in)
1945	92.5 mm (3.6 in)
1946	56.4 mm (2.2 in)
1947	95.5 mm (3.8 in)
1948	88.4 mm (3.5 in)
1949	51.8 mm (2.0 in)
1950	214.9 mm (8.5 in)
1951	43.9 mm (1.7 in)
1952	81.0 mm (3.2 in)
1953	100.1 mm (3.9 in)
1954	47.8 mm (1.9 in)
1955	164.1 mm (6.5 in)
1956	35.3 mm (1.4 in)
1957	54.4 mm (2.1 in)
1958	69.9 mm (2.8 in)
1959	27.2 mm (1.1 in)
1960	53.1 mm (2.1 in)
1961	43.7 mm (1.7 in)

Wettest five days (Rx5day)

The wettest five days of the year at Dahlgren Weapons Lab, 1920 to 1961. The record is 305.5 mm (12.0 in) in 1935, marked on the chart; the median year is 85.8 mm (3.4 in).

Wettest five days (Rx5day) at Dahlgren Weapons Lab by year
Year	Wettest five days (Rx5day)
1920	112.3 mm (4.4 in)
1921	105.3 mm (4.1 in)
1922	83.3 mm (3.3 in)
1923	66.8 mm (2.6 in)
1924	108.4 mm (4.3 in)
1925	72.6 mm (2.9 in)
1926	79.9 mm (3.1 in)
1927	87.1 mm (3.4 in)
1928	51.6 mm (2.0 in)
1929	30.7 mm (1.2 in)
1930	49.3 mm (1.9 in)
1931	71.4 mm (2.8 in)
1932	54.7 mm (2.2 in)
1933	85.8 mm (3.4 in)
1934	103.4 mm (4.1 in)
1935	305.5 mm (12.0 in)
1936	81.5 mm (3.2 in)
1937	124.7 mm (4.9 in)
1938	105.8 mm (4.2 in)
1939	78.0 mm (3.1 in)
1940	85.8 mm (3.4 in)
1941	102.5 mm (4.0 in)
1942	92.7 mm (3.6 in)
1943	55.7 mm (2.2 in)
1944	77.6 mm (3.1 in)
1945	190.5 mm (7.5 in)
1946	86.1 mm (3.4 in)
1947	114.3 mm (4.5 in)
1948	273.9 mm (10.8 in)
1949	103.9 mm (4.1 in)
1950	255.6 mm (10.1 in)
1951	76.1 mm (3.0 in)
1952	151.9 mm (6.0 in)
1953	120.7 mm (4.8 in)
1954	71.9 mm (2.8 in)
1955	209.6 mm (8.3 in)
1956	64.2 mm (2.5 in)
1957	64.6 mm (2.5 in)
1958	177.9 mm (7.0 in)
1959	84.1 mm (3.3 in)
1960	66.1 mm (2.6 in)
1961	58.4 mm (2.3 in)

Longest dry spell (CDD)

The longest dry spell of the year at Dahlgren Weapons Lab, 1920 to 1961. The record is 34 days in 1941, marked on the chart; the median year is 18 days.

Longest dry spell (CDD) at Dahlgren Weapons Lab by year
Year	Longest dry spell (CDD)
1920	18 days
1921	21 days
1922	24 days
1923	25 days
1924	26 days
1925	15 days
1926	15 days
1927	14 days
1928	14 days
1929	3 days
1930	16 days
1931	13 days
1932	21 days
1933	18 days
1934	19 days
1935	15 days
1936	19 days
1937	20 days
1938	20 days
1939	15 days
1940	13 days
1941	34 days
1942	19 days
1943	31 days
1944	23 days
1945	14 days
1946	20 days
1947	26 days
1948	17 days
1949	26 days
1950	15 days
1951	13 days
1952	23 days
1953	26 days
1954	15 days
1955	18 days
1956	17 days
1957	12 days
1958	17 days
1959	21 days
1960	15 days
1961	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

34 years with a frost

Across 34 years with a frost, the median last spring frost at Dahlgren Weapons Lab falls on 3 April and the median first autumn frost on 6 November, which leaves a median of 219 days between them.

Fitted over all years, the growing season changes by +4.8 days per decade at this station.

Frost dates and growing season at Dahlgren Weapons Lab
Measure	Median, all years	Earliest period	Recent period (1925 to 1958)	Recent against earliest	Fitted trend
Last spring frost	3 April	n/a	2 April	n/a	-2.4 days per decade
First autumn frost	6 November	n/a	7 November	n/a	+2.4 days per decade
Growing days	219 days	n/a	221 days	n/a	+4.8 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.

Download the Data

Data for Dahlgren Weapons Lab standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Dahlgren Weapons Lab 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 2026-10-15 (15 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).