Alexandria Potomac Yar Weather Records (USC00440097)

Record envelope, standing records and threshold days for Alexandria Potomac Yar (USC00440097), Virginia, United States, with 70 years of record.

Key Facts for Alexandria Potomac Yar

Alexandria Potomac Yar (USC00440097) is a weather station in Virginia, United States at 38.82 latitude and -77.05 longitude, 6 m (20 ft) above sea level.
The station reports from 1893 to 1962, 70 years of record.
1,464 records set at Alexandria Potomac Yar still stand.
Records are tracked for no element yet: an element needs 30 years of data to be eligible.

About the Station

Location: Virginia, United States, 38.82 latitude, -77.05 longitude.
Elevation: 6 m (20 ft).
Period of record: 1893 to 1962, 70 years.
Eligible elements: none yet.

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 Alexandria Potomac Yar. 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 Alexandria Potomac Yar, 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)	-16.1 C (3.0 F)	n/a	n/a
Feb	24.4 C (75.9 F)	-24.4 C (-11.9 F)	n/a	n/a
Mar	28.9 C (84.0 F)	-11.1 C (12.0 F)	n/a	n/a
Apr	34.4 C (93.9 F)	-4.4 C (24.1 F)	n/a	n/a
May	35.6 C (96.1 F)	2.8 C (37.0 F)	n/a	n/a
Jun	38.9 C (102.0 F)	6.1 C (43.0 F)	n/a	n/a
Jul	40.6 C (105.1 F)	10.6 C (51.1 F)	n/a	n/a
Aug	40.0 C (104.0 F)	10.6 C (51.1 F)	n/a	n/a
Sep	37.8 C (100.0 F)	4.4 C (39.9 F)	n/a	n/a
Oct	33.9 C (93.0 F)	-3.3 C (26.1 F)	n/a	n/a
Nov	31.1 C (88.0 F)	-11.7 C (10.9 F)	n/a	n/a
Dec	22.8 C (73.0 F)	-16.1 C (3.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Alexandria Potomac Yar still stand. 1895 holds the most, with 90.

Standing records at Alexandria Potomac Yar by the year they were set
Year set	Standing records
1893	51
1894	63
1895	90
1896	63
1897	37
1898	58
1899	66
1900	85
1901	60
1902	47
1903	32
1905	18
1906	16
1945	5
1946	38
1947	9
1948	38
1949	64
1950	67
1951	55
1952	48
1953	50
1954	70
1955	28
1956	49
1957	58
1958	28
1959	60
1960	27
1961	47
1962	37

Wettest Day of Each Month

Oct: 121.7 mm (4.8 in)

The wettest day on record for each calendar month at Alexandria Potomac Yar. The most was 121.7 mm (4.8 in) on 14 October 1955.

Record daily precipitation for each month at Alexandria Potomac Yar
Month	Record daily precipitation (mm)	Date
Jan	50.8 mm (2.0 in)	16 January 1957
Feb	45.2 mm (1.8 in)	16 February 1899
Mar	74.9 mm (2.9 in)	20 March 1958
Apr	44.5 mm (1.8 in)	3 April 1901
May	102.9 mm (4.1 in)	6 May 1953
Jun	80.0 mm (3.1 in)	2 June 1959
Jul	76.7 mm (3.0 in)	9 July 1958
Aug	75.7 mm (3.0 in)	8 August 1952
Sep	106.7 mm (4.2 in)	15 September 1900
Oct	121.7 mm (4.8 in)	14 October 1955
Nov	61.0 mm (2.4 in)	8 November 1893
Dec	60.7 mm (2.4 in)	29 December 1901

Period of Record Coverage

1893 to 1962

31 years of record at Alexandria Potomac Yar, 1893 to 1962. 15 years have data for under 90 percent of days and are left out of rankings: 1893, 1895, 1896, 1903, 1905, 1906, 1945, 1946 and others.

Days with data per year at Alexandria Potomac Yar
Year	Days with data	Share of year	Complete
1893	269	74%	No
1894	359	98%	Yes
1895	328	90%	No
1896	186	51%	No
1897	365	100%	Yes
1898	365	100%	Yes
1899	364	100%	Yes
1900	365	100%	Yes
1901	358	98%	Yes
1902	335	92%	Yes
1903	209	57%	No
1905	112	31%	No
1906	74	20%	No
1945	18	5%	No
1946	272	75%	No
1947	37	10%	No
1948	280	77%	No
1949	362	99%	Yes
1950	359	98%	Yes
1951	356	98%	Yes
1952	354	97%	Yes
1953	355	97%	Yes
1954	334	92%	Yes
1955	263	72%	No
1956	353	96%	Yes
1957	355	97%	Yes
1958	327	90%	No
1959	361	99%	Yes
1960	301	82%	No
1961	298	82%	No
1962	300	82%	No

Latest Records

No records were set at this station in the latest data.

Climate Trend

14 complete years, 1894 to 1959

One stripe for each of 14 complete years at Alexandria Potomac Yar, 1894 to 1959. Blue stripes are years cooler than the station's own mean of 14.2 C (57.6 F); red stripes are warmer. The coolest year was 1901, at 12.8 C (55.0 F), and the warmest was 1949, at 15.8 C (60.4 F). The strongest colour marks a difference of 1.6 C (2.9 F).

Annual mean temperature at Alexandria Potomac Yar as warming stripes, 1894 to 1959
Year	Annual mean temperature	Difference from the station mean
1894	13.9 C	-0.35 C
1897	12.8 C	-1.44 C
1898	13.7 C	-0.50 C
1899	13.2 C	-1.06 C
1900	14.3 C	+0.08 C
1901	12.8 C	-1.48 C
1949	15.8 C	+1.52 C
1950	14.5 C	+0.29 C
1951	14.7 C	+0.48 C
1952	14.4 C	+0.18 C
1953	15.2 C	+0.95 C
1956	14.4 C	+0.17 C
1957	15.1 C	+0.84 C
1959	14.6 C	+0.36 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 1962

Yearly extremes at Alexandria Potomac Yar: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	40.6 C (105.1 F)	1898	37.2 C (99.0 F)	31
Coldest night (TNn)	-24.4 C (-11.9 F)	1899	-13.3 C (8.1 F)	31
Wettest day (Rx1day)	121.7 mm (4.8 in)	1955	51.1 mm (2.0 in)	31
Wettest five days (Rx5day)	144.5 mm (5.7 in)	1953	83.8 mm (3.3 in)	31
Longest dry spell (CDD)	33 days	1906	19 days	31

Hottest day (TXx)

The hottest day of the year at Alexandria Potomac Yar, 1893 to 1962. The record is 40.6 C (105.1 F) in 1898, marked on the chart; the median year is 37.2 C (99.0 F).

Hottest day (TXx) at Alexandria Potomac Yar by year
Year	Hottest day (TXx)
1893	35.6 C (96.1 F)
1894	37.2 C (99.0 F)
1895	38.9 C (102.0 F)
1896	34.4 C (93.9 F)
1897	35.0 C (95.0 F)
1898	40.6 C (105.1 F)
1899	37.2 C (99.0 F)
1900	39.4 C (102.9 F)
1901	40.0 C (104.0 F)
1902	38.3 C (100.9 F)
1903	37.8 C (100.0 F)
1905	31.1 C (88.0 F)
1906	21.7 C (71.1 F)
1945	25.6 C (78.1 F)
1946	36.1 C (97.0 F)
1947	31.1 C (88.0 F)
1948	37.2 C (99.0 F)
1949	37.2 C (99.0 F)
1950	36.1 C (97.0 F)
1951	36.7 C (98.1 F)
1952	38.3 C (100.9 F)
1953	38.3 C (100.9 F)
1954	40.0 C (104.0 F)
1955	37.8 C (100.0 F)
1956	36.1 C (97.0 F)
1957	38.9 C (102.0 F)
1958	35.6 C (96.1 F)
1959	37.2 C (99.0 F)
1960	35.0 C (95.0 F)
1961	35.0 C (95.0 F)
1962	37.2 C (99.0 F)

Coldest night (TNn)

The coldest night of the year at Alexandria Potomac Yar, 1893 to 1962. The record is -24.4 C (-11.9 F) in 1899, marked on the chart; the median year is -13.3 C (8.1 F).

Coldest night (TNn) at Alexandria Potomac Yar by year
Year	Coldest night (TNn)
1893	-11.1 C (12.0 F)
1894	-15.0 C (5.0 F)
1895	-17.8 C (0.0 F)
1896	-16.7 C (1.9 F)
1897	-13.9 C (7.0 F)
1898	-14.4 C (6.1 F)
1899	-24.4 C (-11.9 F)
1900	-14.4 C (6.1 F)
1901	-13.9 C (7.0 F)
1902	-15.0 C (5.0 F)
1903	-15.0 C (5.0 F)
1905	-8.9 C (16.0 F)
1906	-13.3 C (8.1 F)
1945	3.3 C (37.9 F)
1946	-11.1 C (12.0 F)
1947	-5.6 C (21.9 F)
1948	-15.0 C (5.0 F)
1949	-7.8 C (18.0 F)
1950	-12.2 C (10.0 F)
1951	-12.8 C (9.0 F)
1952	-10.0 C (14.0 F)
1953	-8.9 C (16.0 F)
1954	-11.7 C (10.9 F)
1955	-11.7 C (10.9 F)
1956	-13.3 C (8.1 F)
1957	-14.4 C (6.1 F)
1958	-15.6 C (3.9 F)
1959	-13.3 C (8.1 F)
1960	-12.8 C (9.0 F)
1961	-15.6 C (3.9 F)
1962	-12.8 C (9.0 F)

Wettest day (Rx1day)

The wettest day of the year at Alexandria Potomac Yar, 1893 to 1962. The record is 121.7 mm (4.8 in) in 1955, marked on the chart; the median year is 51.1 mm (2.0 in).

Wettest day (Rx1day) at Alexandria Potomac Yar by year
Year	Wettest day (Rx1day)
1893	69.9 mm (2.8 in)
1894	50.5 mm (2.0 in)
1895	39.4 mm (1.6 in)
1896	35.6 mm (1.4 in)
1897	53.6 mm (2.1 in)
1898	54.9 mm (2.2 in)
1899	46.0 mm (1.8 in)
1900	106.7 mm (4.2 in)
1901	73.2 mm (2.9 in)
1902	73.2 mm (2.9 in)
1903	95.3 mm (3.8 in)
1905	27.9 mm (1.1 in)
1906	1.8 mm (0.07 in)
1945	33.0 mm (1.3 in)
1946	46.5 mm (1.8 in)
1947	34.3 mm (1.4 in)
1948	50.8 mm (2.0 in)
1949	36.8 mm (1.4 in)
1950	58.4 mm (2.3 in)
1951	50.8 mm (2.0 in)
1952	75.7 mm (3.0 in)
1953	102.9 mm (4.1 in)
1954	41.4 mm (1.6 in)
1955	121.7 mm (4.8 in)
1956	47.0 mm (1.9 in)
1957	55.1 mm (2.2 in)
1958	76.7 mm (3.0 in)
1959	80.0 mm (3.1 in)
1960	86.9 mm (3.4 in)
1961	51.1 mm (2.0 in)
1962	35.3 mm (1.4 in)

Wettest five days (Rx5day)

The wettest five days of the year at Alexandria Potomac Yar, 1893 to 1962. The record is 144.5 mm (5.7 in) in 1953, marked on the chart; the median year is 83.8 mm (3.3 in).

Wettest five days (Rx5day) at Alexandria Potomac Yar by year
Year	Wettest five days (Rx5day)
1893	78.7 mm (3.1 in)
1894	72.6 mm (2.9 in)
1895	66.8 mm (2.6 in)
1896	35.3 mm (1.4 in)
1897	49.0 mm (1.9 in)
1898	119.2 mm (4.7 in)
1899	85.4 mm (3.4 in)
1900	134.9 mm (5.3 in)
1901	104.5 mm (4.1 in)
1902	83.8 mm (3.3 in)
1903	122.0 mm (4.8 in)
1905	27.9 mm (1.1 in)
1906	3.0 mm (0.12 in)
1945	40.6 mm (1.6 in)
1946	79.0 mm (3.1 in)
1947	58.1 mm (2.3 in)
1948	94.5 mm (3.7 in)
1949	70.5 mm (2.8 in)
1950	92.0 mm (3.6 in)
1951	95.3 mm (3.8 in)
1952	120.4 mm (4.7 in)
1953	144.5 mm (5.7 in)
1954	51.0 mm (2.0 in)
1955	142.8 mm (5.6 in)
1956	79.5 mm (3.1 in)
1957	74.4 mm (2.9 in)
1958	134.6 mm (5.3 in)
1959	85.5 mm (3.4 in)
1960	106.7 mm (4.2 in)
1961	101.9 mm (4.0 in)
1962	48.3 mm (1.9 in)

Longest dry spell (CDD)

The longest dry spell of the year at Alexandria Potomac Yar, 1893 to 1962. The record is 33 days in 1906, marked on the chart; the median year is 19 days.

Longest dry spell (CDD) at Alexandria Potomac Yar by year
Year	Longest dry spell (CDD)
1893	16 days
1894	22 days
1895	18 days
1896	27 days
1897	18 days
1898	27 days
1899	13 days
1900	14 days
1901	29 days
1902	18 days
1903	19 days
1905	24 days
1906	33 days
1945	22 days
1946	24 days
1947	16 days
1948	10 days
1949	18 days
1950	16 days
1951	15 days
1952	22 days
1953	21 days
1954	20 days
1955	19 days
1956	16 days
1957	25 days
1958	20 days
1959	26 days
1960	12 days
1961	13 days
1962	22 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.

Download the Data

Data for Alexandria Potomac Yar standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Alexandria Potomac Yar 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).