South Weymouth NAS Weather Records (USW00014790)

Record envelope, standing records and threshold days for South Weymouth NAS (USW00014790), Massachusetts, United States, with 52 years of record.

Key Facts for South Weymouth NAS

South Weymouth NAS (USW00014790) is a weather station in Massachusetts, United States at 42.15 latitude and -70.93 longitude, 48 m (157 ft) above sea level.
The station reports from 1945 to 1996, 52 years of record.
1,464 records set at South Weymouth NAS still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
South Weymouth NAS set a monthly record daily precipitation of 111.5 mm (4.4 in) on 18 September 1996.

About the Station

Location: Massachusetts, United States, 42.15 latitude, -70.93 longitude.
Elevation: 48 m (157 ft).
Period of record: 1945 to 1996, 52 years.
Eligible elements: tmax, tmin, 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 South Weymouth NAS. 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 South Weymouth NAS, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	21.1 C (70.0 F)	-26.1 C (-15.0 F)	n/a	n/a
Feb	20.0 C (68.0 F)	-23.3 C (-9.9 F)	n/a	n/a
Mar	27.2 C (81.0 F)	-16.7 C (1.9 F)	n/a	n/a
Apr	33.9 C (93.0 F)	-9.4 C (15.1 F)	n/a	n/a
May	35.6 C (96.1 F)	-2.2 C (28.0 F)	n/a	n/a
Jun	37.8 C (100.0 F)	3.3 C (37.9 F)	n/a	n/a
Jul	38.3 C (100.9 F)	7.2 C (45.0 F)	n/a	n/a
Aug	38.9 C (102.0 F)	2.8 C (37.0 F)	n/a	n/a
Sep	35.6 C (96.1 F)	-0.6 C (30.9 F)	n/a	n/a
Oct	31.1 C (88.0 F)	-7.8 C (18.0 F)	n/a	n/a
Nov	27.2 C (81.0 F)	-14.4 C (6.1 F)	n/a	n/a
Dec	23.3 C (73.9 F)	-23.3 C (-9.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at South Weymouth NAS still stand. 1965 holds the most, with 49.

Standing records at South Weymouth NAS by the year they were set
Year set	Standing records
1945	34
1954	29
1955	28
1956	41
1957	31
1958	27
1959	31
1960	22
1961	44
1962	46
1963	47
1964	47
1965	49
1966	34
1967	46
1968	42
1969	34
1970	24
1971	31
1972	28
1973	23
1974	28
1975	22
1976	45
1977	25
1978	25
1979	43
1980	26
1981	30
1982	24
1983	20
1984	36
1985	22
1986	28
1987	32
1988	48
1989	37
1990	45
1991	40
1992	46
1993	29
1994	24
1995	30
1996	21

All-Time Record Progression

1 new records

1 all-time records were set at South Weymouth NAS between 11 January 1996 and 11 January 1996. Each dot is a new record.

Wettest Day of Each Month

Aug: 158.2 mm (6.2 in)

The wettest day on record for each calendar month at South Weymouth NAS. The most was 158.2 mm (6.2 in) on 18 August 1955.

Record daily precipitation for each month at South Weymouth NAS
Month	Record daily precipitation (mm)	Date
Jan	67.3 mm (2.6 in)	15 January 1958
Feb	78.7 mm (3.1 in)	13 February 1985
Mar	98.6 mm (3.9 in)	18 March 1968
Apr	71.9 mm (2.8 in)	17 April 1954
May	74.2 mm (2.9 in)	25 May 1967
Jun	61.2 mm (2.4 in)	6 June 1982
Jul	69.1 mm (2.7 in)	24 July 1988
Aug	158.2 mm (6.2 in)	18 August 1955
Sep	111.5 mm (4.4 in)	18 September 1996
Oct	71.6 mm (2.8 in)	31 October 1991
Nov	78.7 mm (3.1 in)	25 November 1983
Dec	69.3 mm (2.7 in)	5 December 1993

Period of Record Coverage

1945 to 1996

45 years of record at South Weymouth NAS, 1945 to 1996. 4 years have data for under 90 percent of days and are left out of rankings: 1945, 1949, 1954, 1996.

Days with data per year at South Weymouth NAS
Year	Days with data	Share of year	Complete
1945	248	68%	No
1949	1	0%	No
1954	291	80%	No
1955	364	100%	Yes
1956	365	100%	Yes
1957	365	100%	Yes
1958	363	99%	Yes
1959	361	99%	Yes
1960	366	100%	Yes
1961	356	98%	Yes
1962	357	98%	Yes
1963	364	100%	Yes
1964	344	94%	Yes
1965	365	100%	Yes
1966	364	100%	Yes
1967	365	100%	Yes
1968	366	100%	Yes
1969	365	100%	Yes
1970	365	100%	Yes
1971	365	100%	Yes
1972	366	100%	Yes
1973	365	100%	Yes
1974	365	100%	Yes
1975	365	100%	Yes
1976	366	100%	Yes
1977	365	100%	Yes
1978	364	100%	Yes
1979	365	100%	Yes
1980	366	100%	Yes
1981	365	100%	Yes
1982	365	100%	Yes
1983	365	100%	Yes
1984	365	100%	Yes
1985	365	100%	Yes
1986	364	100%	Yes
1987	365	100%	Yes
1988	363	99%	Yes
1989	361	99%	Yes
1990	363	99%	Yes
1991	364	100%	Yes
1992	365	100%	Yes
1993	364	100%	Yes
1994	359	98%	Yes
1995	361	99%	Yes
1996	256	70%	No

Latest Records

Latest records at South Weymouth NAS
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
18 September 1996	South Weymouth NAS, US	monthly rain	111.5 mm (4.4 in)	11.7 mm (0.5 in)	34 years	32 of 100 (Routine)
5 September 1996	South Weymouth NAS, US	daily high min	21.1 C (70.0 F)	0.5 C (0.9 F)	35 years	16 of 100 (Routine)
23 August 1996	South Weymouth NAS, US	daily high max	32.2 C (90.0 F)	1.6 C (2.9 F)	18 years	13 of 100 (Routine)
13 August 1996	South Weymouth NAS, US	daily low max	17.8 C (64.0 F)	1.1 C (2.0 F)	13 years	10 of 100 (Routine)
23 July 1996	South Weymouth NAS, US	daily low max (Tie)	21.1 C (70.0 F)	tie	4 years	1 of 100 (Routine)
13 July 1996	South Weymouth NAS, US	daily rain	54.6 mm (2.1 in)	30.2 mm (1.2 in)	27 years	42 of 100 (Notable)
3 July 1996	South Weymouth NAS, US	daily high min	21.1 C (70.0 F)	0.5 C (0.9 F)	38 years	17 of 100 (Routine)
25 June 1996	South Weymouth NAS, US	daily rain	15.2 mm (0.6 in)	0.5 mm (0.02 in)	12 years	8 of 100 (Routine)
21 June 1996	South Weymouth NAS, US	daily rain	8.9 mm (0.35 in)	3.8 mm (0.15 in)	33 years	18 of 100 (Routine)
13 June 1996	South Weymouth NAS, US	daily high min	21.1 C (70.0 F)	1.7 C (3.1 F)	40 years	21 of 100 (Routine)
12 June 1996	South Weymouth NAS, US	daily high min (Tie)	21.7 C (71.1 F)	tie	23 years	2 of 100 (Routine)
30 May 1996	South Weymouth NAS, US	daily low max	13.9 C (57.0 F)	1.1 C (2.0 F)	25 years	13 of 100 (Routine)
21 May 1996	South Weymouth NAS, US	daily rain	35.8 mm (1.4 in)	11.4 mm (0.4 in)	42 years	28 of 100 (Routine)
21 May 1996	South Weymouth NAS, US	daily high min	18.3 C (64.9 F)	1.6 C (2.9 F)	37 years	20 of 100 (Routine)
21 May 1996	South Weymouth NAS, US	monthly high max (Tie)	35.6 C (96.1 F)	tie	8 years	4 of 100 (Routine)
20 May 1996	South Weymouth NAS, US	daily high max	35.0 C (95.0 F)	3.3 C (5.9 F)	37 years	21 of 100 (Routine)
14 May 1996	South Weymouth NAS, US	daily low min (Tie)	0.6 C (33.1 F)	tie	9 years	1 of 100 (Routine)
6 May 1996	South Weymouth NAS, US	daily rain	19.3 mm (0.8 in)	1.0 mm (0.04 in)	38 years	17 of 100 (Routine)
23 April 1996	South Weymouth NAS, US	daily high max	27.8 C (82.0 F)	1.7 C (3.1 F)	23 years	13 of 100 (Routine)
21 April 1996	South Weymouth NAS, US	daily high min (Tie)	13.3 C (55.9 F)	tie	42 years	4 of 100 (Routine)

Climate Trend

39 complete years, 1955 to 1995

One stripe for each of 39 complete years at South Weymouth NAS, 1955 to 1995. Blue stripes are years cooler than the station's own mean of 10.0 C (50.1 F); red stripes are warmer. The coolest year was 1962, at 8.6 C (47.5 F), and the warmest was 1995, at 11.1 C (51.9 F). The strongest colour marks a difference of 1.5 C (2.7 F).

Annual mean temperature at South Weymouth NAS as warming stripes, 1955 to 1995
Year	Annual mean temperature	Difference from the station mean
1955	9.9 C	-0.11 C
1956	9.4 C	-0.61 C
1957	10.5 C	+0.41 C
1958	9.3 C	-0.79 C
1959	10.3 C	+0.28 C
1960	10.0 C	-0.06 C
1961	9.4 C	-0.63 C
1962	8.6 C	-1.44 C
1963	9.0 C	-1.07 C
1965	9.2 C	-0.86 C
1966	9.4 C	-0.62 C
1967	9.7 C	-0.32 C
1968	9.5 C	-0.50 C
1969	9.8 C	-0.23 C
1970	9.9 C	-0.15 C
1971	10.4 C	+0.38 C
1972	9.5 C	-0.50 C
1973	10.9 C	+0.88 C
1974	10.1 C	+0.01 C
1975	10.8 C	+0.78 C
1976	10.2 C	+0.13 C
1977	10.8 C	+0.73 C
1978	9.0 C	-1.05 C
1979	10.4 C	+0.34 C
1980	9.9 C	-0.13 C
1981	10.0 C	+0.00 C
1982	10.0 C	-0.09 C
1983	10.7 C	+0.63 C
1984	10.9 C	+0.83 C
1985	10.4 C	+0.37 C
1986	9.7 C	-0.38 C
1987	10.3 C	+0.22 C
1988	10.7 C	+0.69 C
1989	10.1 C	+0.04 C
1990	10.8 C	+0.72 C
1991	10.7 C	+0.65 C
1992	9.4 C	-0.61 C
1994	10.9 C	+0.90 C
1995	11.1 C	+1.01 C

The annual mean temperature here has risen by 0.3 C (0.1 to 0.4) per decade over 1955 to 1995. In Fahrenheit: 0.5 F (0.2 to 0.8) per decade. The slope is a straight line fitted to 39 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at South Weymouth NAS
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.3 C (0.1 to 0.4) per decade	0.5 F (0.2 to 0.8) per decade	1955 to 1995	39	Rise
Mean daily maximum	0.4 C (0.2 to 0.5) per decade	0.7 F (0.4 to 0.9) per decade	1955 to 1995	39	Rise
Mean daily minimum	0.18 C (-0.04 to 0.39) per decade	0.3 F (-0.1 to 0.7) per decade	1955 to 1995	39	Not clearly different from zero

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

1945 to 1996

Yearly extremes at South Weymouth NAS: 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)	1975	35.0 C (95.0 F)	45
Coldest night (TNn)	-26.1 C (-15.0 F)	1981	-18.9 C (-2.0 F)	45
Wettest day (Rx1day)	158.2 mm (6.2 in)	1955	67.3 mm (2.6 in)	44
Wettest five days (Rx5day)	315.2 mm (12.4 in)	1955	107.7 mm (4.2 in)	44
Longest dry spell (CDD)	27 days	1959	17 days	44

Hottest day (TXx)

The hottest day of the year at South Weymouth NAS, 1945 to 1996. The record is 38.9 C (102.0 F) in 1975, marked on the chart; the median year is 35.0 C (95.0 F).

Hottest day (TXx) at South Weymouth NAS by year
Year	Hottest day (TXx)
1945	33.9 C (93.0 F)
1949	17.2 C (63.0 F)
1954	35.0 C (95.0 F)
1955	37.8 C (100.0 F)
1956	35.0 C (95.0 F)
1957	35.0 C (95.0 F)
1958	33.3 C (91.9 F)
1959	34.4 C (93.9 F)
1960	32.2 C (90.0 F)
1961	33.3 C (91.9 F)
1962	33.3 C (91.9 F)
1963	36.1 C (97.0 F)
1964	36.1 C (97.0 F)
1965	34.4 C (93.9 F)
1966	36.7 C (98.1 F)
1967	35.6 C (96.1 F)
1968	36.1 C (97.0 F)
1969	35.0 C (95.0 F)
1970	34.4 C (93.9 F)
1971	34.4 C (93.9 F)
1972	33.3 C (91.9 F)
1973	34.4 C (93.9 F)
1974	33.9 C (93.0 F)
1975	38.9 C (102.0 F)
1976	33.3 C (91.9 F)
1977	37.2 C (99.0 F)
1978	35.6 C (96.1 F)
1979	33.9 C (93.0 F)
1980	36.7 C (98.1 F)
1981	35.6 C (96.1 F)
1982	36.7 C (98.1 F)
1983	35.6 C (96.1 F)
1984	36.1 C (97.0 F)
1985	34.4 C (93.9 F)
1986	34.4 C (93.9 F)
1987	36.1 C (97.0 F)
1988	38.3 C (100.9 F)
1989	35.6 C (96.1 F)
1990	33.9 C (93.0 F)
1991	37.8 C (100.0 F)
1992	34.4 C (93.9 F)
1993	37.8 C (100.0 F)
1994	36.7 C (98.1 F)
1995	36.7 C (98.1 F)
1996	35.6 C (96.1 F)

Coldest night (TNn)

The coldest night of the year at South Weymouth NAS, 1945 to 1996. The record is -26.1 C (-15.0 F) in 1981, marked on the chart; the median year is -18.9 C (-2.0 F).

Coldest night (TNn) at South Weymouth NAS by year
Year	Coldest night (TNn)
1945	-13.3 C (8.1 F)
1949	3.9 C (39.0 F)
1954	-13.9 C (7.0 F)
1955	-19.4 C (-2.9 F)
1956	-15.0 C (5.0 F)
1957	-24.4 C (-11.9 F)
1958	-20.0 C (-4.0 F)
1959	-18.9 C (-2.0 F)
1960	-17.2 C (1.0 F)
1961	-23.3 C (-9.9 F)
1962	-22.2 C (-8.0 F)
1963	-21.7 C (-7.1 F)
1964	-23.3 C (-9.9 F)
1965	-20.6 C (-5.1 F)
1966	-18.9 C (-2.0 F)
1967	-20.0 C (-4.0 F)
1968	-21.7 C (-7.1 F)
1969	-13.9 C (7.0 F)
1970	-24.4 C (-11.9 F)
1971	-22.8 C (-9.0 F)
1972	-18.9 C (-2.0 F)
1973	-16.1 C (3.0 F)
1974	-17.8 C (0.0 F)
1975	-17.8 C (0.0 F)
1976	-18.9 C (-2.0 F)
1977	-18.3 C (-0.9 F)
1978	-16.7 C (1.9 F)
1979	-20.0 C (-4.0 F)
1980	-23.3 C (-9.9 F)
1981	-26.1 C (-15.0 F)
1982	-21.1 C (-6.0 F)
1983	-18.9 C (-2.0 F)
1984	-22.2 C (-8.0 F)
1985	-16.7 C (1.9 F)
1986	-18.3 C (-0.9 F)
1987	-20.6 C (-5.1 F)
1988	-22.8 C (-9.0 F)
1989	-19.4 C (-2.9 F)
1990	-17.8 C (0.0 F)
1991	-18.9 C (-2.0 F)
1992	-16.7 C (1.9 F)
1993	-16.1 C (3.0 F)
1994	-20.0 C (-4.0 F)
1995	-17.2 C (1.0 F)
1996	-17.8 C (0.0 F)

Wettest day (Rx1day)

The wettest day of the year at South Weymouth NAS, 1945 to 1996. The record is 158.2 mm (6.2 in) in 1955, marked on the chart; the median year is 67.3 mm (2.6 in).

Wettest day (Rx1day) at South Weymouth NAS by year
Year	Wettest day (Rx1day)
1945	67.6 mm (2.7 in)
1949	n/a
1954	71.9 mm (2.8 in)
1955	158.2 mm (6.2 in)
1956	53.3 mm (2.1 in)
1957	46.2 mm (1.8 in)
1958	67.3 mm (2.6 in)
1959	41.7 mm (1.6 in)
1960	83.1 mm (3.3 in)
1961	99.8 mm (3.9 in)
1962	71.1 mm (2.8 in)
1963	43.7 mm (1.7 in)
1964	38.4 mm (1.5 in)
1965	48.5 mm (1.9 in)
1966	90.2 mm (3.6 in)
1967	74.2 mm (2.9 in)
1968	98.6 mm (3.9 in)
1969	67.1 mm (2.6 in)
1970	67.8 mm (2.7 in)
1971	57.2 mm (2.3 in)
1972	95.5 mm (3.8 in)
1973	71.9 mm (2.8 in)
1974	62.5 mm (2.5 in)
1975	51.1 mm (2.0 in)
1976	80.0 mm (3.1 in)
1977	51.6 mm (2.0 in)
1978	72.9 mm (2.9 in)
1979	60.5 mm (2.4 in)
1980	56.4 mm (2.2 in)
1981	59.2 mm (2.3 in)
1982	61.2 mm (2.4 in)
1983	78.7 mm (3.1 in)
1984	73.2 mm (2.9 in)
1985	78.7 mm (3.1 in)
1986	58.7 mm (2.3 in)
1987	59.7 mm (2.4 in)
1988	69.6 mm (2.7 in)
1989	63.0 mm (2.5 in)
1990	66.0 mm (2.6 in)
1991	71.6 mm (2.8 in)
1992	62.7 mm (2.5 in)
1993	69.3 mm (2.7 in)
1994	64.5 mm (2.5 in)
1995	67.3 mm (2.6 in)
1996	111.5 mm (4.4 in)

Wettest five days (Rx5day)

The wettest five days of the year at South Weymouth NAS, 1945 to 1996. The record is 315.2 mm (12.4 in) in 1955, marked on the chart; the median year is 107.7 mm (4.2 in).

Wettest five days (Rx5day) at South Weymouth NAS by year
Year	Wettest five days (Rx5day)
1945	135.9 mm (5.4 in)
1949	n/a
1954	94.0 mm (3.7 in)
1955	315.2 mm (12.4 in)
1956	113.1 mm (4.5 in)
1957	124.7 mm (4.9 in)
1958	77.0 mm (3.0 in)
1959	67.9 mm (2.7 in)
1960	97.6 mm (3.8 in)
1961	178.3 mm (7.0 in)
1962	175.2 mm (6.9 in)
1963	89.2 mm (3.5 in)
1964	64.7 mm (2.5 in)
1965	55.9 mm (2.2 in)
1966	92.7 mm (3.6 in)
1967	94.8 mm (3.7 in)
1968	147.6 mm (5.8 in)
1969	117.7 mm (4.6 in)
1970	92.3 mm (3.6 in)
1971	89.1 mm (3.5 in)
1972	95.5 mm (3.8 in)
1973	103.1 mm (4.1 in)
1974	67.3 mm (2.6 in)
1975	105.9 mm (4.2 in)
1976	139.4 mm (5.5 in)
1977	82.1 mm (3.2 in)
1978	114.1 mm (4.5 in)
1979	114.9 mm (4.5 in)
1980	74.1 mm (2.9 in)
1981	109.5 mm (4.3 in)
1982	166.8 mm (6.6 in)
1983	103.6 mm (4.1 in)
1984	153.2 mm (6.0 in)
1985	147.5 mm (5.8 in)
1986	95.0 mm (3.7 in)
1987	128.1 mm (5.0 in)
1988	133.9 mm (5.3 in)
1989	122.0 mm (4.8 in)
1990	86.8 mm (3.4 in)
1991	140.5 mm (5.5 in)
1992	114.5 mm (4.5 in)
1993	84.5 mm (3.3 in)
1994	122.2 mm (4.8 in)
1995	85.3 mm (3.4 in)
1996	140.2 mm (5.5 in)

Longest dry spell (CDD)

The longest dry spell of the year at South Weymouth NAS, 1945 to 1996. The record is 27 days in 1959, marked on the chart; the median year is 17 days.

Longest dry spell (CDD) at South Weymouth NAS by year
Year	Longest dry spell (CDD)
1945	10 days
1949	n/a
1954	16 days
1955	18 days
1956	15 days
1957	14 days
1958	21 days
1959	27 days
1960	18 days
1961	17 days
1962	16 days
1963	16 days
1964	20 days
1965	22 days
1966	14 days
1967	21 days
1968	22 days
1969	16 days
1970	17 days
1971	14 days
1972	10 days
1973	15 days
1974	15 days
1975	22 days
1976	23 days
1977	22 days
1978	22 days
1979	12 days
1980	26 days
1981	14 days
1982	19 days
1983	11 days
1984	19 days
1985	16 days
1986	18 days
1987	22 days
1988	15 days
1989	17 days
1990	20 days
1991	12 days
1992	15 days
1993	13 days
1994	16 days
1995	20 days
1996	12 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

39 years with a frost

Across 39 years with a frost, the median last spring frost at South Weymouth NAS falls on 23 April and the median first autumn frost on 16 October, which leaves a median of 178 days between them.

Fitted over all years, the growing season changes by -0.4 days per decade at this station.

Frost dates and growing season at South Weymouth NAS
Measure	Median, all years	Earliest period	Recent period (1965 to 1995)	Recent against earliest	Fitted trend
Last spring frost	23 April	n/a	23 April	n/a	-0.1 days per decade
First autumn frost	16 October	n/a	16 October	n/a	-0.5 days per decade
Growing days	178 days	n/a	176 days	n/a	-0.4 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.

Rainfall Return Levels

41 years, 1955 to 1995

A day with at least 64.8 mm (2.6 in) of rain is expected about once in 2 years. A day with at least 133.2 mm (5.2 in) of rain is expected about once in 100 years.

Rainfall return levels at South Weymouth NAS: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	64.8 mm (2.6 in)
5 years	81.2 mm (3.2 in)
10 years	92.8 mm (3.7 in)
25 years	108.3 mm (4.3 in)
50 years	120.5 mm (4.7 in)	Longer than the 41 years of record
100 years	133.2 mm (5.2 in)	Longer than the 41 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, 41 years of values from 1955 to 1995.

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: 158.2 mm (6.2 in) in 1955; 99.8 mm (3.9 in) in 1961; 98.6 mm (3.9 in) in 1968.

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Data for South Weymouth NAS standing records by year: CSV or JSON. Field meanings are on the data page.
Data for South Weymouth NAS 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 2026-10-17 (17 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).