Record envelope, standing records and threshold days for Williamstown (USC00199731), Massachusetts, United States, with 63 years of record.
Key Facts for Williamstown
Williamstown (USC00199731) is a weather station in Massachusetts, United States at 42.72 latitude and -73.20 longitude, 217 m (711 ft) above sea level.
The station reports from 1885 to 1947, 63 years of record.
1,464 records set at Williamstown still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Williamstown set a daily record low minimum temperature of -21.7 C (-7.1 F) on 25 December 1947.
About the Station
Location: Massachusetts, United States, 42.72 latitude, -73.20 longitude.
Elevation: 217 m (711 ft).
Period of record: 1885 to 1947, 63 years.
Eligible elements: tmax, tmin, prcp.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Williamstown. 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 Williamstown, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
17.8 C (64.0 F)
-32.2 C (-26.0 F)
n/a
n/a
Feb
15.6 C (60.1 F)
-31.1 C (-24.0 F)
n/a
n/a
Mar
26.1 C (79.0 F)
-25.6 C (-14.1 F)
n/a
n/a
Apr
31.1 C (88.0 F)
-16.1 C (3.0 F)
n/a
n/a
May
33.3 C (91.9 F)
-3.9 C (25.0 F)
n/a
n/a
Jun
35.6 C (96.1 F)
1.7 C (35.1 F)
n/a
n/a
Jul
36.1 C (97.0 F)
0.6 C (33.1 F)
n/a
n/a
Aug
35.6 C (96.1 F)
-1.1 C (30.0 F)
n/a
n/a
Sep
32.8 C (91.0 F)
-4.4 C (24.1 F)
n/a
n/a
Oct
30.0 C (86.0 F)
-8.9 C (16.0 F)
n/a
n/a
Nov
22.2 C (72.0 F)
-22.2 C (-8.0 F)
n/a
n/a
Dec
18.9 C (66.0 F)
-30.6 C (-23.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Williamstown still stand. 1888 holds the most, with 60.
Standing records at Williamstown by the year they were set
Year set
Standing records
1885
29
1886
26
1887
37
1888
60
1892
6
1893
16
1894
31
1895
10
1897
14
1898
22
1899
25
1901
20
1902
25
1903
34
1904
28
1905
21
1906
33
1907
23
1908
21
1909
20
1910
19
1911
40
1912
28
1913
36
1914
39
1915
23
1916
35
1917
27
1918
45
1919
26
1920
21
1921
26
1922
16
1923
20
1924
21
1925
34
1926
24
1927
28
1928
23
1929
33
1930
33
1931
17
1932
24
1933
32
1934
21
1935
17
1936
29
1937
24
1938
34
1939
19
1940
27
1941
27
1942
12
1943
20
1944
15
1945
19
1946
7
1947
22
Wettest Day of Each Month
Jul: 146.3 mm (5.8 in)
The wettest day on record for each calendar month at Williamstown. The most was 146.3 mm (5.8 in) on 24 July 1887.
Record daily precipitation for each month at Williamstown
Month
Record daily precipitation (mm)
Date
Jan
55.9 mm (2.2 in)
17 January 1885
Feb
43.2 mm (1.7 in)
5 February 1921
Mar
56.9 mm (2.2 in)
6 March 1887
Apr
136.9 mm (5.4 in)
24 April 1944
May
54.9 mm (2.2 in)
8 May 1886
Jun
73.4 mm (2.9 in)
19 June 1934
Jul
146.3 mm (5.8 in)
24 July 1887
Aug
77.0 mm (3.0 in)
30 August 1885
Sep
84.3 mm (3.3 in)
21 September 1938
Oct
74.2 mm (2.9 in)
5 October 1898
Nov
129.0 mm (5.1 in)
3 November 1927
Dec
44.2 mm (1.7 in)
28 December 1946
Period of Record Coverage
1885 to 1947
Complete yearUnder 90 percent of days
58 years of record at Williamstown, 1885 to 1947. 9 years have data for under 90 percent of days and are left out of rankings: 1885, 1888, 1892, 1895, 1897, 1922, 1943, 1945 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 44 complete years at Williamstown, 1886 to 1940. Blue stripes are years cooler than the station's own mean of 7.7 C (45.8 F); red stripes are warmer. The coolest year was 1904, at 5.9 C (42.6 F), and the warmest was 1913, at 8.9 C (48.1 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at Williamstown as warming stripes, 1886 to 1940
Year
Annual mean temperature
Difference from the station mean
1886
7.2 C
-0.50 C
1887
6.8 C
-0.83 C
1894
8.0 C
+0.37 C
1898
8.0 C
+0.30 C
1899
7.5 C
-0.14 C
1901
7.3 C
-0.41 C
1902
7.5 C
-0.12 C
1903
7.6 C
-0.09 C
1904
5.9 C
-1.77 C
1905
6.9 C
-0.74 C
1906
7.7 C
+0.08 C
1907
6.8 C
-0.88 C
1908
8.0 C
+0.35 C
1909
7.6 C
-0.08 C
1910
7.8 C
+0.09 C
1911
8.1 C
+0.48 C
1912
7.3 C
-0.39 C
1913
8.9 C
+1.28 C
1914
7.0 C
-0.63 C
1915
8.2 C
+0.50 C
1916
7.2 C
-0.48 C
1917
6.3 C
-1.41 C
1918
7.5 C
-0.13 C
1919
8.1 C
+0.46 C
1920
7.2 C
-0.48 C
1921
8.9 C
+1.27 C
1923
7.3 C
-0.41 C
1924
6.9 C
-0.74 C
1925
7.7 C
+0.02 C
1926
6.5 C
-1.17 C
1927
7.9 C
+0.27 C
1928
8.0 C
+0.38 C
1929
8.0 C
+0.30 C
1930
8.5 C
+0.83 C
1931
8.9 C
+1.26 C
1932
8.5 C
+0.81 C
1933
8.4 C
+0.71 C
1934
7.6 C
-0.07 C
1935
7.4 C
-0.26 C
1936
8.1 C
+0.40 C
1937
8.5 C
+0.87 C
1938
8.8 C
+1.12 C
1939
8.1 C
+0.42 C
1940
6.9 C
-0.81 C
The annual mean temperature here has risen by 0.17 C (0.03 to 0.32) per decade over 1886 to 1940. In Fahrenheit: 0.31 F (0.05 to 0.57) per decade. The slope is a straight line fitted to 44 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Williamstown
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.17 C (0.03 to 0.32) per decade
0.31 F (0.05 to 0.57) per decade
1886 to 1940
44
Rise
Mean daily maximum
0.19 C (0.03 to 0.35) per decade
0.3 F (0.1 to 0.6) per decade
1886 to 1940
44
Rise
Mean daily minimum
0.15 C (0.01 to 0.30) per decade
0.28 F (0.02 to 0.54) per decade
1886 to 1940
44
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
1885 to 1947
Yearly extremes at Williamstown: 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)
1911
32.2 C (90.0 F)
58
Coldest night (TNn)
-32.2 C (-26.0 F)
1899
-25.6 C (-14.1 F)
58
Wettest day (Rx1day)
146.3 mm (5.8 in)
1887
54.5 mm (2.1 in)
60
Wettest five days (Rx5day)
178.3 mm (7.0 in)
1938
77.5 mm (3.0 in)
60
Longest dry spell (CDD)
37 days
1924
15 days
60
Hottest day (TXx)
The hottest day of the year at Williamstown, 1885 to 1947. The record is 36.1 C (97.0 F) in 1911, marked on the chart; the median year is 32.2 C (90.0 F).
Hottest day (TXx) at Williamstown by year
Year
Hottest day (TXx)
1885
27.2 C (81.0 F)
1886
31.1 C (88.0 F)
1887
31.1 C (88.0 F)
1888
31.1 C (88.0 F)
1892
31.7 C (89.1 F)
1893
30.6 C (87.1 F)
1894
32.2 C (90.0 F)
1895
32.2 C (90.0 F)
1896
n/a
1897
32.2 C (90.0 F)
1898
32.2 C (90.0 F)
1899
31.1 C (88.0 F)
1900
n/a
1901
32.8 C (91.0 F)
1902
29.4 C (84.9 F)
1903
30.6 C (87.1 F)
1904
31.1 C (88.0 F)
1905
30.6 C (87.1 F)
1906
30.6 C (87.1 F)
1907
30.6 C (87.1 F)
1908
31.7 C (89.1 F)
1909
31.7 C (89.1 F)
1910
33.9 C (93.0 F)
1911
36.1 C (97.0 F)
1912
34.4 C (93.9 F)
1913
35.0 C (95.0 F)
1914
32.2 C (90.0 F)
1915
30.6 C (87.1 F)
1916
32.2 C (90.0 F)
1917
35.0 C (95.0 F)
1918
35.6 C (96.1 F)
1919
33.9 C (93.0 F)
1920
30.6 C (87.1 F)
1921
32.2 C (90.0 F)
1922
32.2 C (90.0 F)
1923
32.8 C (91.0 F)
1924
32.2 C (90.0 F)
1925
32.8 C (91.0 F)
1926
35.0 C (95.0 F)
1927
32.8 C (91.0 F)
1928
35.6 C (96.1 F)
1929
32.8 C (91.0 F)
1930
33.9 C (93.0 F)
1931
33.3 C (91.9 F)
1932
32.8 C (91.0 F)
1933
35.0 C (95.0 F)
1934
32.2 C (90.0 F)
1935
32.2 C (90.0 F)
1936
33.9 C (93.0 F)
1937
32.8 C (91.0 F)
1938
31.7 C (89.1 F)
1939
32.8 C (91.0 F)
1940
32.2 C (90.0 F)
1941
32.8 C (91.0 F)
1942
32.2 C (90.0 F)
1943
32.2 C (90.0 F)
1944
34.4 C (93.9 F)
1945
32.8 C (91.0 F)
1946
17.8 C (64.0 F)
1947
35.6 C (96.1 F)
Coldest night (TNn)
The coldest night of the year at Williamstown, 1885 to 1947. The record is -32.2 C (-26.0 F) in 1899, marked on the chart; the median year is -25.6 C (-14.1 F).
Coldest night (TNn) at Williamstown by year
Year
Coldest night (TNn)
1885
-25.6 C (-14.1 F)
1886
-27.2 C (-17.0 F)
1887
-27.2 C (-17.0 F)
1888
-27.2 C (-17.0 F)
1892
-20.0 C (-4.0 F)
1893
-25.0 C (-13.0 F)
1894
-26.7 C (-16.1 F)
1895
-26.1 C (-15.0 F)
1896
n/a
1897
-19.4 C (-2.9 F)
1898
-25.6 C (-14.1 F)
1899
-32.2 C (-26.0 F)
1900
n/a
1901
-24.4 C (-11.9 F)
1902
-25.6 C (-14.1 F)
1903
-21.7 C (-7.1 F)
1904
-31.1 C (-24.0 F)
1905
-22.2 C (-8.0 F)
1906
-22.2 C (-8.0 F)
1907
-26.1 C (-15.0 F)
1908
-28.3 C (-18.9 F)
1909
-22.8 C (-9.0 F)
1910
-25.0 C (-13.0 F)
1911
-22.2 C (-8.0 F)
1912
-26.1 C (-15.0 F)
1913
-20.6 C (-5.1 F)
1914
-30.6 C (-23.1 F)
1915
-19.4 C (-2.9 F)
1916
-25.6 C (-14.1 F)
1917
-28.9 C (-20.0 F)
1918
-28.3 C (-18.9 F)
1919
-26.7 C (-16.1 F)
1920
-31.1 C (-24.0 F)
1921
-23.3 C (-9.9 F)
1922
-24.4 C (-11.9 F)
1923
-22.8 C (-9.0 F)
1924
-26.7 C (-16.1 F)
1925
-28.3 C (-18.9 F)
1926
-24.4 C (-11.9 F)
1927
-25.6 C (-14.1 F)
1928
-21.7 C (-7.1 F)
1929
-22.8 C (-9.0 F)
1930
-26.1 C (-15.0 F)
1931
-28.3 C (-18.9 F)
1932
-23.9 C (-11.0 F)
1933
-29.4 C (-20.9 F)
1934
-31.1 C (-24.0 F)
1935
-28.9 C (-20.0 F)
1936
-22.2 C (-8.0 F)
1937
-17.2 C (1.0 F)
1938
-28.3 C (-18.9 F)
1939
-24.4 C (-11.9 F)
1940
-24.4 C (-11.9 F)
1941
-22.8 C (-9.0 F)
1942
-23.3 C (-9.9 F)
1943
-30.6 C (-23.1 F)
1944
-22.8 C (-9.0 F)
1945
-30.6 C (-23.1 F)
1946
-23.3 C (-9.9 F)
1947
-21.7 C (-7.1 F)
Wettest day (Rx1day)
The wettest day of the year at Williamstown, 1885 to 1947. The record is 146.3 mm (5.8 in) in 1887, marked on the chart; the median year is 54.5 mm (2.1 in).
Wettest day (Rx1day) at Williamstown by year
Year
Wettest day (Rx1day)
1885
77.0 mm (3.0 in)
1886
54.9 mm (2.2 in)
1887
146.3 mm (5.8 in)
1888
69.1 mm (2.7 in)
1892
57.2 mm (2.3 in)
1893
42.4 mm (1.7 in)
1894
44.5 mm (1.8 in)
1895
52.1 mm (2.1 in)
1896
57.4 mm (2.3 in)
1897
86.4 mm (3.4 in)
1898
74.2 mm (2.9 in)
1899
51.6 mm (2.0 in)
1900
66.0 mm (2.6 in)
1901
51.3 mm (2.0 in)
1902
41.7 mm (1.6 in)
1903
63.5 mm (2.5 in)
1904
63.0 mm (2.5 in)
1905
56.6 mm (2.2 in)
1906
43.2 mm (1.7 in)
1907
56.9 mm (2.2 in)
1908
48.8 mm (1.9 in)
1909
58.7 mm (2.3 in)
1910
39.9 mm (1.6 in)
1911
36.3 mm (1.4 in)
1912
56.9 mm (2.2 in)
1913
40.1 mm (1.6 in)
1914
49.0 mm (1.9 in)
1915
94.7 mm (3.7 in)
1916
50.8 mm (2.0 in)
1917
43.2 mm (1.7 in)
1918
56.9 mm (2.2 in)
1919
60.5 mm (2.4 in)
1920
56.1 mm (2.2 in)
1921
55.9 mm (2.2 in)
1922
58.4 mm (2.3 in)
1923
51.6 mm (2.0 in)
1924
30.2 mm (1.2 in)
1925
63.2 mm (2.5 in)
1926
38.1 mm (1.5 in)
1927
129.0 mm (5.1 in)
1928
43.9 mm (1.7 in)
1929
24.1 mm (0.9 in)
1930
31.5 mm (1.2 in)
1931
49.3 mm (1.9 in)
1932
43.9 mm (1.7 in)
1933
59.7 mm (2.4 in)
1934
73.4 mm (2.9 in)
1935
52.6 mm (2.1 in)
1936
54.1 mm (2.1 in)
1937
74.9 mm (2.9 in)
1938
84.3 mm (3.3 in)
1939
34.8 mm (1.4 in)
1940
82.3 mm (3.2 in)
1941
40.9 mm (1.6 in)
1942
50.8 mm (2.0 in)
1943
68.1 mm (2.7 in)
1944
136.9 mm (5.4 in)
1945
52.1 mm (2.1 in)
1946
44.2 mm (1.7 in)
1947
45.5 mm (1.8 in)
Wettest five days (Rx5day)
The wettest five days of the year at Williamstown, 1885 to 1947. The record is 178.3 mm (7.0 in) in 1938, marked on the chart; the median year is 77.5 mm (3.0 in).
Wettest five days (Rx5day) at Williamstown by year
Year
Wettest five days (Rx5day)
1885
77.0 mm (3.0 in)
1886
73.2 mm (2.9 in)
1887
72.9 mm (2.9 in)
1888
49.2 mm (1.9 in)
1892
63.8 mm (2.5 in)
1893
72.9 mm (2.9 in)
1894
49.6 mm (2.0 in)
1895
55.9 mm (2.2 in)
1896
71.4 mm (2.8 in)
1897
56.9 mm (2.2 in)
1898
89.9 mm (3.5 in)
1899
65.8 mm (2.6 in)
1900
92.6 mm (3.6 in)
1901
99.0 mm (3.9 in)
1902
59.7 mm (2.4 in)
1903
124.7 mm (4.9 in)
1904
107.4 mm (4.2 in)
1905
81.5 mm (3.2 in)
1906
87.6 mm (3.4 in)
1907
95.5 mm (3.8 in)
1908
80.0 mm (3.1 in)
1909
65.6 mm (2.6 in)
1910
92.5 mm (3.6 in)
1911
73.4 mm (2.9 in)
1912
98.0 mm (3.9 in)
1913
81.2 mm (3.2 in)
1914
63.0 mm (2.5 in)
1915
106.9 mm (4.2 in)
1916
56.4 mm (2.2 in)
1917
66.0 mm (2.6 in)
1918
71.2 mm (2.8 in)
1919
74.7 mm (2.9 in)
1920
90.5 mm (3.6 in)
1921
94.5 mm (3.7 in)
1922
84.0 mm (3.3 in)
1923
84.9 mm (3.3 in)
1924
58.9 mm (2.3 in)
1925
109.8 mm (4.3 in)
1926
54.1 mm (2.1 in)
1927
157.0 mm (6.2 in)
1928
80.4 mm (3.2 in)
1929
51.6 mm (2.0 in)
1930
47.0 mm (1.9 in)
1931
86.1 mm (3.4 in)
1932
64.2 mm (2.5 in)
1933
85.7 mm (3.4 in)
1934
92.3 mm (3.6 in)
1935
77.5 mm (3.1 in)
1936
86.9 mm (3.4 in)
1937
142.7 mm (5.6 in)
1938
178.3 mm (7.0 in)
1939
60.5 mm (2.4 in)
1940
112.3 mm (4.4 in)
1941
56.4 mm (2.2 in)
1942
73.4 mm (2.9 in)
1943
103.8 mm (4.1 in)
1944
81.5 mm (3.2 in)
1945
72.7 mm (2.9 in)
1946
48.3 mm (1.9 in)
1947
77.4 mm (3.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at Williamstown, 1885 to 1947. The record is 37 days in 1924, marked on the chart; the median year is 15 days.
Longest dry spell (CDD) at Williamstown by year
Year
Longest dry spell (CDD)
1885
13 days
1886
13 days
1887
11 days
1888
12 days
1892
9 days
1893
9 days
1894
12 days
1895
16 days
1896
13 days
1897
15 days
1898
23 days
1899
15 days
1900
17 days
1901
23 days
1902
11 days
1903
20 days
1904
17 days
1905
18 days
1906
11 days
1907
13 days
1908
32 days
1909
13 days
1910
14 days
1911
16 days
1912
28 days
1913
17 days
1914
26 days
1915
23 days
1916
11 days
1917
20 days
1918
18 days
1919
14 days
1920
12 days
1921
14 days
1922
20 days
1923
13 days
1924
37 days
1925
12 days
1926
9 days
1927
16 days
1928
12 days
1929
14 days
1930
17 days
1931
13 days
1932
17 days
1933
11 days
1934
12 days
1935
13 days
1936
13 days
1937
10 days
1938
22 days
1939
20 days
1940
15 days
1941
22 days
1942
16 days
1943
15 days
1944
16 days
1945
8 days
1946
9 days
1947
36 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
44 years with a frost
Across 44 years with a frost, the median last spring frost at Williamstown falls on 5 May and the median first autumn frost on 8 October, which leaves a median of 153 days between them.
Fitted over all years, the growing season changes by -0.7 days per decade at this station.
Frost dates and growing season at Williamstown
Measure
Median, all years
Earliest period
Recent period (1910 to 1940)
Recent against earliest
Fitted trend
Last spring frost
5 May
n/a
5 May
n/a
+1.2 days per decade
First autumn frost
8 October
n/a
8 October
n/a
+0.6 days per decade
Growing days
153 days
n/a
156 days
n/a
-0.7 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
45 years, 1886 to 1947
A day with at least 51.5 mm (2.0 in) of rain is expected about once in 2 years. A day with at least 114.1 mm (4.5 in) of rain is expected about once in 100 years.
Rainfall return levels at Williamstown: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
51.5 mm (2.0 in)
5 years
66.9 mm (2.6 in)
10 years
77.6 mm (3.1 in)
25 years
91.8 mm (3.6 in)
50 years
102.8 mm (4.0 in)
Longer than the 45 years of record
100 years
114.1 mm (4.5 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 1886 to 1947.
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: 129.0 mm (5.1 in) in 1927; 94.7 mm (3.7 in) in 1915; 84.3 mm (3.3 in) in 1938.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Williamstown standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Williamstown 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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.