Williamsport Weather Records (USC00189570)

Record envelope, standing records and threshold days for Williamsport (USC00189570), Maryland, United States, with 89 years of record.

Key Facts for Williamsport

Williamsport (USC00189570) is a weather station in Maryland, United States at 39.61 latitude and -77.85 longitude, 110 m (360 ft) above sea level.
The station reports from 1938 to 2026, 89 years of record.
1,464 records set at Williamsport still stand.
Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
Williamsport set a daily record precipitation of 60.5 mm (2.4 in) on 12 October 2026 (provisional).

Provisional Records

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

About the Station

Location: Maryland, United States, 39.61 latitude, -77.85 longitude.
Elevation: 110 m (360 ft).
Period of record: 1938 to 2026, 89 years.
Eligible elements: prcp, snow, snwd.

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 Williamsport. 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 Williamsport, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	22.2 C (72.0 F)	-20.0 C (-4.0 F)	n/a	n/a
Feb	23.3 C (73.9 F)	-17.8 C (0.0 F)	n/a	n/a
Mar	28.3 C (82.9 F)	-16.1 C (3.0 F)	n/a	n/a
Apr	34.4 C (93.9 F)	-5.6 C (21.9 F)	n/a	n/a
May	35.6 C (96.1 F)	0.0 C (32.0 F)	n/a	n/a
Jun	38.3 C (100.9 F)	5.6 C (42.1 F)	n/a	n/a
Jul	38.9 C (102.0 F)	10.6 C (51.1 F)	n/a	n/a
Aug	37.2 C (99.0 F)	8.9 C (48.0 F)	n/a	n/a
Sep	37.2 C (99.0 F)	3.9 C (39.0 F)	n/a	n/a
Oct	32.8 C (91.0 F)	-4.4 C (24.1 F)	n/a	n/a
Nov	25.6 C (78.1 F)	-8.3 C (17.1 F)	n/a	n/a
Dec	23.3 C (73.9 F)	-15.6 C (3.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Williamsport still stand. 2005 holds the most, with 148.

All-Time Record Progression

4 new records

4 all-time records were set at Williamsport between 10 July 1970 and 2 September 2021. Each dot is a new record.

When Williamsport set new all-time records
Date	Kind	Detail
1970-07-10	Record daily precipitation	Record daily precipitation 105.7 mm (4.2 in)
1972-06-22	Record daily precipitation	Record daily precipitation 107.4 mm (4.2 in)
2006-06-26	Record daily precipitation	Record daily precipitation 119.9 mm (4.7 in)
2021-09-02	Record daily precipitation	Record daily precipitation 146.1 mm (5.8 in)

Wettest Day of Each Month

Sep: 146.1 mm (5.8 in)

The wettest day on record for each calendar month at Williamsport. The most was 146.1 mm (5.8 in) on 2 September 2021.

Record daily precipitation for each month at Williamsport
Month	Record daily precipitation (mm)	Date
Jan	59.9 mm (2.4 in)	2 January 1948
Feb	43.7 mm (1.7 in)	8 February 1965
Mar	66.3 mm (2.6 in)	29 March 2005
Apr	63.2 mm (2.5 in)	17 April 2011
May	81.5 mm (3.2 in)	26 May 1952
Jun	119.9 mm (4.7 in)	26 June 2006
Jul	105.7 mm (4.2 in)	10 July 1970
Aug	80.0 mm (3.1 in)	21 August 2015
Sep	146.1 mm (5.8 in)	2 September 2021
Oct	92.7 mm (3.6 in)	11 October 2013
Nov	63.5 mm (2.5 in)	7 November 1963
Dec	63.5 mm (2.5 in)	16 December 2018

Period of Record Coverage

1967 to 2014

16 years of record at Williamsport, 1967 to 2014. 9 years have data for under 90 percent of days and are left out of rankings: 1967, 1968, 1970, 1971, 1972, 1975, 2007, 2012 and others.

Days with data per year at Williamsport
Year	Days with data	Share of year	Complete
1967	31	8%	No
1968	31	8%	No
1970	1	0%	No
1971	303	83%	No
1972	119	33%	No
1975	91	25%	No
2005	333	91%	Yes
2006	354	97%	Yes
2007	244	67%	No
2008	341	93%	Yes
2009	333	91%	Yes
2010	336	92%	Yes
2011	351	96%	Yes
2012	320	87%	No
2013	339	93%	Yes
2014	197	54%	No

Latest Records

Latest records at Williamsport
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
12 October 2026	Williamsport, US	daily rain (Provisional)	60.5 mm (2.4 in)	1.6 mm (0.06 in)	12 years	12 of 100 (Routine)
23 August 2026	Williamsport, US	daily rain (Provisional)	34.3 mm (1.4 in)	8.4 mm (0.33 in)	80 years	39 of 100 (Notable)
23 May 2026	Williamsport, US	daily rain (Tie)	38.1 mm (1.5 in)	tie	16 years	3 of 100 (Routine)
20 February 2026	Williamsport, US	daily rain	29.0 mm (1.1 in)	4.1 mm (0.16 in)	80 years	37 of 100 (Notable)
26 January 2026	Williamsport, US	daily rain	27.9 mm (1.1 in)	13.4 mm (0.5 in)	74 years	46 of 100 (Notable)
19 December 2025	Williamsport, US	daily rain	15.0 mm (0.6 in)	0.8 mm (0.03 in)	74 years	20 of 100 (Routine)
1 August 2025	Williamsport, US	daily rain	48.0 mm (1.9 in)	20.6 mm (0.8 in)	12 years	28 of 100 (Routine)
1 July 2025	Williamsport, US	daily rain	19.1 mm (0.8 in)	3.6 mm (0.14 in)	12 years	13 of 100 (Routine)
14 May 2025	Williamsport, US	daily rain	53.1 mm (2.1 in)	30.0 mm (1.2 in)	60 years	55 of 100 (Notable)
16 February 2025	Williamsport, US	daily rain	19.3 mm (0.8 in)	4.8 mm (0.19 in)	86 years	20 of 100 (Routine)
10 August 2024	Williamsport, US	daily rain	33.5 mm (1.3 in)	8.6 mm (0.34 in)	12 years	18 of 100 (Routine)
15 June 2024	Williamsport, US	daily rain	34.3 mm (1.4 in)	13.0 mm (0.5 in)	64 years	36 of 100 (Notable)
10 May 2024	Williamsport, US	daily rain	19.1 mm (0.8 in)	8.9 mm (0.35 in)	52 years	20 of 100 (Routine)
3 April 2024	Williamsport, US	daily rain	34.3 mm (1.4 in)	15.0 mm (0.6 in)	50 years	39 of 100 (Notable)
10 March 2024	Williamsport, US	daily rain	32.5 mm (1.3 in)	13.4 mm (0.5 in)	5 years	23 of 100 (Routine)
29 February 2024	Williamsport, US	daily rain (Tie)	7.1 mm (0.28 in)	tie	60 years	6 of 100 (Routine)
23 February 2024	Williamsport, US	daily rain	18.5 mm (0.7 in)	2.2 mm (0.09 in)	52 years	20 of 100 (Routine)
13 February 2024	Williamsport, US	daily rain	30.5 mm (1.2 in)	7.6 mm (0.30 in)	57 years	34 of 100 (Routine)
10 January 2024	Williamsport, US	daily rain	43.2 mm (1.7 in)	18.1 mm (0.7 in)	66 years	50 of 100 (Notable)
7 January 2024	Williamsport, US	daily rain	21.1 mm (0.8 in)	2.3 mm (0.09 in)	14 years	14 of 100 (Routine)

Extremes by Year

1938 to 2026

Yearly extremes at Williamsport: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	38.9 C (102.0 F)	2011	34.7 C (94.5 F)	16
Coldest night (TNn)	-20.0 C (-4.0 F)	1972	-15.3 C (4.5 F)	16
Wettest day (Rx1day)	146.1 mm (5.8 in)	2021	62.1 mm (2.4 in)	60
Wettest five days (Rx5day)	207.0 mm (8.1 in)	2021	86.9 mm (3.4 in)	60
Longest dry spell (CDD)	36 days	2005	18 days	60

Hottest day (TXx)

The hottest day of the year at Williamsport, 1938 to 2026. The record is 38.9 C (102.0 F) in 2011, marked on the chart; the median year is 34.7 C (94.5 F).

Hottest day (TXx) at Williamsport 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
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
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	n/a
1965	n/a
1966	n/a
1967	26.7 C (80.1 F)
1968	14.4 C (57.9 F)
1969	n/a
1970	3.3 C (37.9 F)
1971	34.4 C (93.9 F)
1972	30.6 C (87.1 F)
1973	n/a
1974	n/a
1975	27.8 C (82.0 F)
2005	36.7 C (98.1 F)
2006	36.7 C (98.1 F)
2007	36.1 C (97.0 F)
2008	35.0 C (95.0 F)
2009	34.4 C (93.9 F)
2010	38.3 C (100.9 F)
2011	38.9 C (102.0 F)
2012	38.3 C (100.9 F)
2013	36.1 C (97.0 F)
2014	33.9 C (93.0 F)
2015	n/a
2016	n/a
2017	n/a
2018	n/a
2019	n/a
2020	n/a
2021	n/a
2022	n/a
2023	n/a
2024	n/a
2025	n/a
2026	n/a

Coldest night (TNn)

The coldest night of the year at Williamsport, 1938 to 2026. The record is -20.0 C (-4.0 F) in 1972, marked on the chart; the median year is -15.3 C (4.5 F).

Coldest night (TNn) at Williamsport 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
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
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	n/a
1965	n/a
1966	n/a
1967	1.7 C (35.1 F)
1968	-15.6 C (3.9 F)
1969	n/a
1970	-10.0 C (14.0 F)
1971	-15.0 C (5.0 F)
1972	-20.0 C (-4.0 F)
1973	n/a
1974	n/a
1975	-4.4 C (24.1 F)
2005	-17.8 C (0.0 F)
2006	-11.7 C (10.9 F)
2007	-15.6 C (3.9 F)
2008	-13.3 C (8.1 F)
2009	-17.2 C (1.0 F)
2010	-16.7 C (1.9 F)
2011	-16.7 C (1.9 F)
2012	-11.7 C (10.9 F)
2013	-12.2 C (10.0 F)
2014	-17.8 C (0.0 F)
2015	n/a
2016	n/a
2017	n/a
2018	n/a
2019	n/a
2020	n/a
2021	n/a
2022	n/a
2023	n/a
2024	n/a
2025	n/a
2026	n/a

Wettest day (Rx1day)

The wettest day of the year at Williamsport, 1938 to 2026. The record is 146.1 mm (5.8 in) in 2021, marked on the chart; the median year is 62.1 mm (2.4 in).

Wettest day (Rx1day) at Williamsport by year
Year	Wettest day (Rx1day)
1938	36.8 mm (1.4 in)
1939	74.7 mm (2.9 in)
1940	50.8 mm (2.0 in)
1941	40.6 mm (1.6 in)
1942	69.9 mm (2.8 in)
1943	58.9 mm (2.3 in)
1944	51.6 mm (2.0 in)
1945	83.8 mm (3.3 in)
1946	68.6 mm (2.7 in)
1947	67.6 mm (2.7 in)
1948	62.5 mm (2.5 in)
1949	80.0 mm (3.1 in)
1950	62.7 mm (2.5 in)
1951	41.1 mm (1.6 in)
1952	98.3 mm (3.9 in)
1953	104.6 mm (4.1 in)
1954	81.5 mm (3.2 in)
1955	74.4 mm (2.9 in)
1956	71.6 mm (2.8 in)
1957	32.5 mm (1.3 in)
1958	42.2 mm (1.7 in)
1959	41.4 mm (1.6 in)
1960	48.8 mm (1.9 in)
1961	34.5 mm (1.4 in)
1962	33.3 mm (1.3 in)
1963	63.5 mm (2.5 in)
1964	46.5 mm (1.8 in)
1965	97.5 mm (3.8 in)
1966	80.5 mm (3.2 in)
1967	62.2 mm (2.4 in)
1968	42.9 mm (1.7 in)
1969	56.4 mm (2.2 in)
1970	105.7 mm (4.2 in)
1971	60.5 mm (2.4 in)
1972	107.4 mm (4.2 in)
1973	56.6 mm (2.2 in)
1974	58.4 mm (2.3 in)
1975	91.4 mm (3.6 in)
2005	76.2 mm (3.0 in)
2006	119.9 mm (4.7 in)
2007	39.1 mm (1.5 in)
2008	59.4 mm (2.3 in)
2009	47.5 mm (1.9 in)
2010	41.1 mm (1.6 in)
2011	63.2 mm (2.5 in)
2012	41.7 mm (1.6 in)
2013	92.7 mm (3.6 in)
2014	73.2 mm (2.9 in)
2015	80.0 mm (3.1 in)
2016	36.3 mm (1.4 in)
2017	62.0 mm (2.4 in)
2018	69.3 mm (2.7 in)
2019	64.8 mm (2.6 in)
2020	53.3 mm (2.1 in)
2021	146.1 mm (5.8 in)
2022	54.1 mm (2.1 in)
2023	63.5 mm (2.5 in)
2024	54.6 mm (2.1 in)
2025	53.1 mm (2.1 in)
2026	60.5 mm (2.4 in)

Wettest five days (Rx5day)

The wettest five days of the year at Williamsport, 1938 to 2026. The record is 207.0 mm (8.1 in) in 2021, marked on the chart; the median year is 86.9 mm (3.4 in).

Wettest five days (Rx5day) at Williamsport by year
Year	Wettest five days (Rx5day)
1938	52.3 mm (2.1 in)
1939	95.3 mm (3.8 in)
1940	71.4 mm (2.8 in)
1941	70.4 mm (2.8 in)
1942	162.2 mm (6.4 in)
1943	68.8 mm (2.7 in)
1944	58.1 mm (2.3 in)
1945	131.1 mm (5.2 in)
1946	84.6 mm (3.3 in)
1947	118.4 mm (4.7 in)
1948	80.8 mm (3.2 in)
1949	101.5 mm (4.0 in)
1950	98.3 mm (3.9 in)
1951	93.8 mm (3.7 in)
1952	135.7 mm (5.3 in)
1953	105.1 mm (4.1 in)
1954	83.8 mm (3.3 in)
1955	99.6 mm (3.9 in)
1956	97.1 mm (3.8 in)
1957	58.9 mm (2.3 in)
1958	76.3 mm (3.0 in)
1959	62.2 mm (2.4 in)
1960	93.7 mm (3.7 in)
1961	62.9 mm (2.5 in)
1962	60.8 mm (2.4 in)
1963	102.9 mm (4.1 in)
1964	64.5 mm (2.5 in)
1965	97.5 mm (3.8 in)
1966	127.5 mm (5.0 in)
1967	75.2 mm (3.0 in)
1968	100.7 mm (4.0 in)
1969	88.6 mm (3.5 in)
1970	135.9 mm (5.4 in)
1971	102.9 mm (4.1 in)
1972	189.9 mm (7.5 in)
1973	85.3 mm (3.4 in)
1974	77.7 mm (3.1 in)
1975	177.6 mm (7.0 in)
2005	118.6 mm (4.7 in)
2006	187.0 mm (7.4 in)
2007	72.0 mm (2.8 in)
2008	77.4 mm (3.0 in)
2009	66.4 mm (2.6 in)
2010	65.0 mm (2.6 in)
2011	121.4 mm (4.8 in)
2012	71.9 mm (2.8 in)
2013	173.2 mm (6.8 in)
2014	76.5 mm (3.0 in)
2015	81.5 mm (3.2 in)
2016	67.8 mm (2.7 in)
2017	82.3 mm (3.2 in)
2018	145.0 mm (5.7 in)
2019	79.9 mm (3.1 in)
2020	56.4 mm (2.2 in)
2021	207.0 mm (8.1 in)
2022	97.7 mm (3.8 in)
2023	65.0 mm (2.6 in)
2024	112.5 mm (4.4 in)
2025	62.0 mm (2.4 in)
2026	97.2 mm (3.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at Williamsport, 1938 to 2026. The record is 36 days in 2005, marked on the chart; the median year is 18 days.

Longest dry spell (CDD) at Williamsport by year
Year	Longest dry spell (CDD)
1938	14 days
1939	19 days
1940	14 days
1941	28 days
1942	21 days
1943	18 days
1944	18 days
1945	14 days
1946	17 days
1947	35 days
1948	13 days
1949	15 days
1950	15 days
1951	16 days
1952	29 days
1953	22 days
1954	18 days
1955	21 days
1956	15 days
1957	15 days
1958	24 days
1959	16 days
1960	20 days
1961	15 days
1962	16 days
1963	27 days
1964	26 days
1965	18 days
1966	22 days
1967	18 days
1968	33 days
1969	17 days
1970	16 days
1971	26 days
1972	9 days
1973	25 days
1974	18 days
1975	18 days
2005	36 days
2006	20 days
2007	27 days
2008	26 days
2009	18 days
2010	22 days
2011	14 days
2012	9 days
2013	15 days
2014	9 days
2015	15 days
2016	8 days
2017	16 days
2018	12 days
2019	17 days
2020	18 days
2021	18 days
2022	12 days
2023	17 days
2024	34 days
2025	16 days
2026	17 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

45 years, 1939 to 2025

A day with at least 60.9 mm (2.4 in) of rain is expected about once in 2 years. A day with at least 147.4 mm (5.8 in) of rain is expected about once in 100 years.

Rainfall return levels at Williamsport: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	60.9 mm (2.4 in)
5 years	81.6 mm (3.2 in)
10 years	96.2 mm (3.8 in)
25 years	115.9 mm (4.6 in)
50 years	131.3 mm (5.2 in)	Longer than the 45 years of record
100 years	147.4 mm (5.8 in)	Longer than the 45 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, 45 years of values from 1939 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: 146.1 mm (5.8 in) in 2021; 119.9 mm (4.7 in) in 2006; 105.7 mm (4.2 in) in 1970.

Download the Data

Data for Williamsport standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Williamsport 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 2026-10-15. Last revised 15 October 2026 (2026-10-15).