Record envelope, standing records and threshold days for Boston City WSO (USW00094701), Massachusetts, United States, with 43 years of record.
Key Facts for Boston City WSO
Boston City WSO (USW00094701) is a weather station in Massachusetts, United States at 42.35 latitude and -71.07 longitude, 6 m (20 ft) above sea level.
The station reports from 1893 to 1935, 43 years of record.
1,464 records set at Boston City WSO still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Boston City WSO tied a daily record low minimum temperature of -10.6 C (12.9 F) on 23 December 1935.
About the Station
Location: Massachusetts, United States, 42.35 latitude, -71.07 longitude.
Elevation: 6 m (20 ft).
Period of record: 1893 to 1935, 43 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
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 Boston City WSO. 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 Boston City WSO, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
20.6 C (69.1 F)
-23.3 C (-9.9 F)
n/a
n/a
Feb
20.0 C (68.0 F)
-27.8 C (-18.0 F)
n/a
n/a
Mar
28.3 C (82.9 F)
-15.6 C (3.9 F)
n/a
n/a
Apr
31.7 C (89.1 F)
-10.6 C (12.9 F)
n/a
n/a
May
35.6 C (96.1 F)
0.6 C (33.1 F)
n/a
n/a
Jun
37.8 C (100.0 F)
5.6 C (42.1 F)
n/a
n/a
Jul
40.0 C (104.0 F)
10.6 C (51.1 F)
n/a
n/a
Aug
36.7 C (98.1 F)
8.3 C (46.9 F)
n/a
n/a
Sep
36.1 C (97.0 F)
1.1 C (34.0 F)
n/a
n/a
Oct
31.7 C (89.1 F)
-2.8 C (27.0 F)
n/a
n/a
Nov
25.6 C (78.1 F)
-13.3 C (8.1 F)
n/a
n/a
Dec
20.6 C (69.1 F)
-27.2 C (-17.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Boston City WSO still stand. 1903 holds the most, with 60.
Standing records at Boston City WSO by the year they were set
Year set
Standing records
1893
33
1894
48
1895
53
1896
47
1897
37
1898
37
1899
28
1900
44
1901
33
1902
28
1903
60
1904
35
1905
20
1906
34
1907
37
1908
35
1909
31
1910
19
1911
39
1912
28
1913
32
1914
54
1915
31
1916
39
1917
38
1918
40
1919
31
1920
28
1921
36
1922
18
1923
33
1924
31
1925
33
1926
17
1927
32
1928
33
1929
30
1930
41
1931
26
1932
29
1933
38
1934
27
1935
21
All-Time Record Progression
2 new records
2 all-time records were set at Boston City WSO between 29 December 1933 and 9 February 1934. Each dot is a new record.
When Boston City WSO set new all-time records
Date
Kind
Detail
1933-12-29
Record low minimum temperature
Record low minimum temperature -27.2 C (-17.0 F)
1934-02-09
Record low minimum temperature
Record low minimum temperature -27.8 C (-18.0 F)
Wettest Day of Each Month
Jul: 153.4 mm (6.0 in)
The wettest day on record for each calendar month at Boston City WSO. The most was 153.4 mm (6.0 in) on 9 July 1921.
Record daily precipitation for each month at Boston City WSO
Month
Record daily precipitation (mm)
Date
Jan
55.6 mm (2.2 in)
10 January 1935
Feb
62.2 mm (2.4 in)
21 February 1898
Mar
61.7 mm (2.4 in)
28 March 1932
Apr
75.4 mm (3.0 in)
28 April 1904
May
82.0 mm (3.2 in)
22 May 1920
Jun
84.3 mm (3.3 in)
19 June 1922
Jul
153.4 mm (6.0 in)
9 July 1921
Aug
105.4 mm (4.1 in)
26 August 1924
Sep
143.0 mm (5.6 in)
16 September 1933
Oct
123.2 mm (4.9 in)
13 October 1895
Nov
67.8 mm (2.7 in)
1 November 1895
Dec
58.9 mm (2.3 in)
27 December 1894
Period of Record Coverage
1893 to 1935
Complete yearUnder 90 percent of days
43 years of record at Boston City WSO, 1893 to 1935. Every year has data for at least 90 percent of its days.
Cooler than the station meanWarmer than the station mean
One stripe for each of 43 complete years at Boston City WSO, 1893 to 1935. Blue stripes are years cooler than the station's own mean of 10.2 C (50.3 F); red stripes are warmer. The coolest year was 1904, at 8.4 C (47.1 F), and the warmest was 1931, at 11.6 C (53.0 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at Boston City WSO as warming stripes, 1893 to 1935
Year
Annual mean temperature
Difference from the station mean
1893
8.8 C
-1.36 C
1894
10.2 C
+0.04 C
1895
9.9 C
-0.25 C
1896
9.6 C
-0.60 C
1897
10.0 C
-0.20 C
1898
10.4 C
+0.24 C
1899
10.1 C
-0.09 C
1900
10.5 C
+0.31 C
1901
9.4 C
-0.74 C
1902
9.8 C
-0.35 C
1903
9.7 C
-0.43 C
1904
8.4 C
-1.78 C
1905
9.5 C
-0.66 C
1906
10.0 C
-0.16 C
1907
9.3 C
-0.90 C
1908
10.7 C
+0.48 C
1909
10.3 C
+0.12 C
1910
10.4 C
+0.25 C
1911
10.5 C
+0.33 C
1912
10.3 C
+0.13 C
1913
11.3 C
+1.10 C
1914
9.8 C
-0.34 C
1915
10.7 C
+0.50 C
1916
9.8 C
-0.35 C
1917
8.9 C
-1.32 C
1918
9.9 C
-0.25 C
1919
10.6 C
+0.44 C
1920
10.0 C
-0.16 C
1921
11.3 C
+1.14 C
1922
10.7 C
+0.53 C
1923
10.2 C
0.00 C
1924
10.2 C
+0.06 C
1925
11.0 C
+0.78 C
1926
9.4 C
-0.73 C
1927
11.0 C
+0.82 C
1928
10.7 C
+0.57 C
1929
10.7 C
+0.55 C
1930
11.3 C
+1.11 C
1931
11.6 C
+1.47 C
1932
11.3 C
+1.17 C
1933
10.5 C
+0.34 C
1934
9.4 C
-0.81 C
1935
9.4 C
-0.79 C
The annual mean temperature here has risen by 0.2 C (0.1 to 0.4) per decade over 1893 to 1935. In Fahrenheit: 0.4 F (0.1 to 0.7) per decade. The slope is a straight line fitted to 43 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Boston City WSO
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.2 C (0.1 to 0.4) per decade
0.4 F (0.1 to 0.7) per decade
1893 to 1935
43
Rise
Mean daily maximum
0.3 C (0.1 to 0.4) per decade
0.5 F (0.1 to 0.8) per decade
1893 to 1935
43
Rise
Mean daily minimum
0.2 C (0.1 to 0.4) per decade
0.4 F (0.1 to 0.7) per decade
1893 to 1935
43
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
1893 to 1935
Yearly extremes at Boston City WSO: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.0 C (104.0 F)
1911
35.0 C (95.0 F)
43
Coldest night (TNn)
-27.8 C (-18.0 F)
1934
-19.4 C (-2.9 F)
43
Wettest day (Rx1day)
153.4 mm (6.0 in)
1921
62.2 mm (2.4 in)
43
Wettest five days (Rx5day)
202.2 mm (8.0 in)
1933
91.5 mm (3.6 in)
43
Longest dry spell (CDD)
44 days
1924
19 days
43
Hottest day (TXx)
The hottest day of the year at Boston City WSO, 1893 to 1935. The record is 40.0 C (104.0 F) in 1911, marked on the chart; the median year is 35.0 C (95.0 F).
Hottest day (TXx) at Boston City WSO by year
Year
Hottest day (TXx)
1893
34.4 C (93.9 F)
1894
36.1 C (97.0 F)
1895
35.6 C (96.1 F)
1896
35.0 C (95.0 F)
1897
34.4 C (93.9 F)
1898
37.2 C (99.0 F)
1899
34.4 C (93.9 F)
1900
36.1 C (97.0 F)
1901
36.1 C (97.0 F)
1902
33.3 C (91.9 F)
1903
33.9 C (93.0 F)
1904
33.3 C (91.9 F)
1905
34.4 C (93.9 F)
1906
33.9 C (93.0 F)
1907
34.4 C (93.9 F)
1908
36.1 C (97.0 F)
1909
35.0 C (95.0 F)
1910
34.4 C (93.9 F)
1911
40.0 C (104.0 F)
1912
37.2 C (99.0 F)
1913
35.6 C (96.1 F)
1914
35.0 C (95.0 F)
1915
34.4 C (93.9 F)
1916
35.0 C (95.0 F)
1917
36.7 C (98.1 F)
1918
36.7 C (98.1 F)
1919
38.3 C (100.9 F)
1920
33.9 C (93.0 F)
1921
35.0 C (95.0 F)
1922
33.9 C (93.0 F)
1923
35.6 C (96.1 F)
1924
36.7 C (98.1 F)
1925
37.8 C (100.0 F)
1926
39.4 C (102.9 F)
1927
35.0 C (95.0 F)
1928
35.6 C (96.1 F)
1929
36.1 C (97.0 F)
1930
36.7 C (98.1 F)
1931
36.1 C (97.0 F)
1932
33.9 C (93.0 F)
1933
37.2 C (99.0 F)
1934
34.4 C (93.9 F)
1935
33.3 C (91.9 F)
Coldest night (TNn)
The coldest night of the year at Boston City WSO, 1893 to 1935. The record is -27.8 C (-18.0 F) in 1934, marked on the chart; the median year is -19.4 C (-2.9 F).
Coldest night (TNn) at Boston City WSO by year
Year
Coldest night (TNn)
1893
-20.0 C (-4.0 F)
1894
-21.7 C (-7.1 F)
1895
-21.1 C (-6.0 F)
1896
-23.9 C (-11.0 F)
1897
-16.7 C (1.9 F)
1898
-17.8 C (0.0 F)
1899
-20.0 C (-4.0 F)
1900
-20.0 C (-4.0 F)
1901
-19.4 C (-2.9 F)
1902
-22.2 C (-8.0 F)
1903
-18.3 C (-0.9 F)
1904
-21.1 C (-6.0 F)
1905
-16.1 C (3.0 F)
1906
-18.3 C (-0.9 F)
1907
-21.7 C (-7.1 F)
1908
-18.9 C (-2.0 F)
1909
-16.1 C (3.0 F)
1910
-19.4 C (-2.9 F)
1911
-15.6 C (3.9 F)
1912
-20.6 C (-5.1 F)
1913
-16.1 C (3.0 F)
1914
-23.9 C (-11.0 F)
1915
-16.1 C (3.0 F)
1916
-17.8 C (0.0 F)
1917
-25.6 C (-14.1 F)
1918
-23.3 C (-9.9 F)
1919
-21.1 C (-6.0 F)
1920
-22.2 C (-8.0 F)
1921
-17.8 C (0.0 F)
1922
-20.0 C (-4.0 F)
1923
-16.7 C (1.9 F)
1924
-21.1 C (-6.0 F)
1925
-17.8 C (0.0 F)
1926
-15.6 C (3.9 F)
1927
-17.8 C (0.0 F)
1928
-18.3 C (-0.9 F)
1929
-14.4 C (6.1 F)
1930
-18.3 C (-0.9 F)
1931
-17.2 C (1.0 F)
1932
-17.8 C (0.0 F)
1933
-27.2 C (-17.0 F)
1934
-27.8 C (-18.0 F)
1935
-20.6 C (-5.1 F)
Wettest day (Rx1day)
The wettest day of the year at Boston City WSO, 1893 to 1935. The record is 153.4 mm (6.0 in) in 1921, marked on the chart; the median year is 62.2 mm (2.4 in).
Wettest day (Rx1day) at Boston City WSO by year
Year
Wettest day (Rx1day)
1893
68.8 mm (2.7 in)
1894
58.9 mm (2.3 in)
1895
123.2 mm (4.9 in)
1896
53.3 mm (2.1 in)
1897
45.0 mm (1.8 in)
1898
62.2 mm (2.4 in)
1899
71.6 mm (2.8 in)
1900
61.0 mm (2.4 in)
1901
53.3 mm (2.1 in)
1902
46.7 mm (1.8 in)
1903
62.2 mm (2.4 in)
1904
88.4 mm (3.5 in)
1905
73.2 mm (2.9 in)
1906
60.7 mm (2.4 in)
1907
71.9 mm (2.8 in)
1908
43.9 mm (1.7 in)
1909
61.7 mm (2.4 in)
1910
43.9 mm (1.7 in)
1911
88.6 mm (3.5 in)
1912
64.0 mm (2.5 in)
1913
36.1 mm (1.4 in)
1914
42.2 mm (1.7 in)
1915
113.0 mm (4.4 in)
1916
51.6 mm (2.0 in)
1917
75.4 mm (3.0 in)
1918
58.4 mm (2.3 in)
1919
74.7 mm (2.9 in)
1920
82.0 mm (3.2 in)
1921
153.4 mm (6.0 in)
1922
84.3 mm (3.3 in)
1923
40.1 mm (1.6 in)
1924
105.4 mm (4.1 in)
1925
41.9 mm (1.6 in)
1926
59.2 mm (2.3 in)
1927
47.8 mm (1.9 in)
1928
42.9 mm (1.7 in)
1929
63.5 mm (2.5 in)
1930
82.0 mm (3.2 in)
1931
78.0 mm (3.1 in)
1932
79.5 mm (3.1 in)
1933
143.0 mm (5.6 in)
1934
47.5 mm (1.9 in)
1935
55.6 mm (2.2 in)
Wettest five days (Rx5day)
The wettest five days of the year at Boston City WSO, 1893 to 1935. The record is 202.2 mm (8.0 in) in 1933, marked on the chart; the median year is 91.5 mm (3.6 in).
Wettest five days (Rx5day) at Boston City WSO by year
Year
Wettest five days (Rx5day)
1893
105.4 mm (4.1 in)
1894
69.9 mm (2.8 in)
1895
145.4 mm (5.7 in)
1896
97.3 mm (3.8 in)
1897
66.8 mm (2.6 in)
1898
87.2 mm (3.4 in)
1899
76.9 mm (3.0 in)
1900
96.1 mm (3.8 in)
1901
96.5 mm (3.8 in)
1902
82.6 mm (3.3 in)
1903
84.6 mm (3.3 in)
1904
136.9 mm (5.4 in)
1905
121.4 mm (4.8 in)
1906
93.4 mm (3.7 in)
1907
78.8 mm (3.1 in)
1908
72.4 mm (2.9 in)
1909
85.9 mm (3.4 in)
1910
72.7 mm (2.9 in)
1911
110.2 mm (4.3 in)
1912
90.2 mm (3.6 in)
1913
69.6 mm (2.7 in)
1914
60.0 mm (2.4 in)
1915
142.8 mm (5.6 in)
1916
68.3 mm (2.7 in)
1917
103.1 mm (4.1 in)
1918
76.1 mm (3.0 in)
1919
107.8 mm (4.2 in)
1920
90.2 mm (3.6 in)
1921
153.4 mm (6.0 in)
1922
132.1 mm (5.2 in)
1923
68.8 mm (2.7 in)
1924
111.0 mm (4.4 in)
1925
99.3 mm (3.9 in)
1926
77.2 mm (3.0 in)
1927
77.8 mm (3.1 in)
1928
68.8 mm (2.7 in)
1929
91.5 mm (3.6 in)
1930
91.7 mm (3.6 in)
1931
133.3 mm (5.2 in)
1932
150.1 mm (5.9 in)
1933
202.2 mm (8.0 in)
1934
76.2 mm (3.0 in)
1935
106.1 mm (4.2 in)
Longest dry spell (CDD)
The longest dry spell of the year at Boston City WSO, 1893 to 1935. The record is 44 days in 1924, marked on the chart; the median year is 19 days.
Longest dry spell (CDD) at Boston City WSO by year
Year
Longest dry spell (CDD)
1893
18 days
1894
16 days
1895
21 days
1896
26 days
1897
15 days
1898
15 days
1899
22 days
1900
18 days
1901
27 days
1902
16 days
1903
17 days
1904
18 days
1905
21 days
1906
14 days
1907
12 days
1908
21 days
1909
15 days
1910
23 days
1911
17 days
1912
34 days
1913
16 days
1914
25 days
1915
36 days
1916
19 days
1917
21 days
1918
19 days
1919
15 days
1920
26 days
1921
19 days
1922
20 days
1923
22 days
1924
44 days
1925
20 days
1926
17 days
1927
15 days
1928
19 days
1929
20 days
1930
36 days
1931
16 days
1932
18 days
1933
13 days
1934
17 days
1935
20 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
43 years with a frost
Across 43 years with a frost, the median last spring frost at Boston City WSO falls on 12 April and the median first autumn frost on 3 November, which leaves a median of 204 days between them.
Fitted over all years, the growing season changes by -1.9 days per decade at this station.
Frost dates and growing season at Boston City WSO
Measure
Median, all years
Earliest period
Recent period (1906 to 1935)
Recent against earliest
Fitted trend
Last spring frost
12 April
n/a
13 April
n/a
+1.3 days per decade
First autumn frost
3 November
n/a
4 November
n/a
-0.7 days per decade
Growing days
204 days
n/a
205 days
n/a
-1.9 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
43 years, 1893 to 1935
A day with at least 62.2 mm (2.4 in) of rain is expected about once in 2 years. A day with at least 171.6 mm (6.8 in) of rain is expected about once in 100 years.
Rainfall return levels at Boston City WSO: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
62.2 mm (2.4 in)
5 years
84.4 mm (3.3 in)
10 years
101.5 mm (4.0 in)
25 years
126.5 mm (5.0 in)
50 years
147.8 mm (5.8 in)
Longer than the 43 years of record
100 years
171.6 mm (6.8 in)
Longer than the 43 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, 43 years of values from 1893 to 1935.
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: 153.4 mm (6.0 in) in 1921; 143.0 mm (5.6 in) in 1933; 123.2 mm (4.9 in) in 1895.
Station Changes
2 suspected
2 changes were suspected in the annual mean temperature of Boston City WSO, at 1905 and 1931. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1905 ran 0.4 C (0.7 F) higher than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1931 ran 0.4 C (0.7 F) lower than in the years before (likely change).
Suspected changes in the annual mean temperature at Boston City WSO, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1905
+0.4
+0.7
likely
5
1931
-0.4
-0.7
likely
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Download the Data
Data for Boston City WSO standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Boston City WSO 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.