Built 2026-10-19 (19 October 2026)

Days at or above 35 C (95 F) in Boston

Boston has had days with a maximum temperature at or above 35 C (95 F) in 69 years, most in 1949 with 14. Days per year, season span, streaks and every date.

Key Facts for Boston

  • Boston has had days with a maximum temperature at or above 35 C (95 F) in 69 years, 284 days in all.
  • The most in one year was 14 days in 1949.
  • In 2026, the latest year on file, there were 3 such days.
  • The earliest first date in a year was 9 May 1979.
  • The latest last date in a year was 20 September 1983.
  • The longest run inside a single year was 7 days in 1944.
  • 1 year with under 90 percent of days observed is left out of these rankings.

Days per Year

69 years, 284 days
Days at or above 35 C (95 F) per year in Boston Days per year in Boston with a maximum temperature at or above 35 C (95 F). The line is the decade average. The most was 14 in 1949. Grey bars are years with under 90 percent of days observed, left out of rankings. 0510151936: 11937: 41939: 11940: 21941: 31943: 31944: 121945: 31946: 11947: 51948: 51949: 141952: 61953: 81954: 21955: 91956: 21957: 41959: 51961: 11963: 71964: 11966: 11968: 21969: 31973: 61974: 11975: 31976: 11977: 61978: 21979: 21980: 51981: 21982: 41983: 91984: 71986: 11987: 21988: 71989: 11991: 51993: 61994: 41995: 41997: 11999: 52001: 22002: 72005: 32006: 32007: 52008: 32009: 12010: 42011: 32012: 42013: 62015: 12016: 62017: 32018: 92019: 52020: 32021: 82022: 72024: 52025: 42026: 31936194819631978198920062017
Days per year in Boston with a maximum temperature at or above 35 C (95 F). The line is the decade average. The most was 14 in 1949. Grey bars are years with under 90 percent of days observed, left out of rankings.
Days at or above 35 C (95 F) per year in Boston
YearDaysDecade average
193612
193742
193912
194025.3
194135.3
194335.3
1944125.3
194535.3
194615.3
194755.3
194855.3
1949145.3
195265.1
195385.1
195425.1
195595.1
195625.1
195745.1
195955.1
196112.5
196372.5
196412.5
196612.5
196822.5
196932.5
197363
197413
197533
197613
197763
197823
197923
198054.2
198124.2
198244.2
198394.2
198474.2
198614.2
198724.2
198874.2
198914.2
199154.2
199364.2
199444.2
199544.2
199714.2
199954.2
200123.4
200273.4
200533.4
200633.4
200753.4
200833.4
200913.4
201044.6
201134.6
201244.6
201364.6
201514.6
201664.6
201734.6
201894.6
201954.6
202035
202185
202275
202455
202545
202635

Season Span

earliest 9 May, latest 20 September
First to last qualifying date each year in Boston For each year, a bar from the first to the last day in Boston meeting 35 C (95 F). Long bars mean a long season. 1936: 8 July 1936 to 8 July 19361937: 1 June 1937 to 21 August 19371939: 16 September 1939 to 16 September 19391940: 26 July 1940 to 30 July 19401941: 22 June 1941 to 2 July 19411943: 3 June 1943 to 28 June 19431944: 31 May 1944 to 17 August 19441945: 15 June 1945 to 7 September 19451946: 19 July 1946 to 19 July 19461947: 13 August 1947 to 25 August 19471948: 12 July 1948 to 28 August 19481949: 21 June 1949 to 28 August 19491952: 26 June 1952 to 23 July 19521953: 20 June 1953 to 2 September 19531954: 14 July 1954 to 31 July 19541955: 2 July 1955 to 21 August 19551956: 13 June 1956 to 15 June 19561957: 15 June 1957 to 3 August 19571959: 10 June 1959 to 21 August 19591961: 13 June 1961 to 13 June 19611963: 26 June 1963 to 28 July 19631964: 1 July 1964 to 1 July 19641966: 3 July 1966 to 3 July 19661968: 1 July 1968 to 16 July 19681969: 27 June 1969 to 1 September 19691973: 11 June 1973 to 30 August 19731974: 4 July 1974 to 4 July 19741975: 31 July 1975 to 2 August 19751976: 24 June 1976 to 24 June 19761977: 17 July 1977 to 29 August 19771978: 21 July 1978 to 23 July 19781979: 9 May 1979 to 16 June 19791980: 25 June 1980 to 2 September 19801981: 8 July 1981 to 9 July 19811982: 8 July 1982 to 19 July 19821983: 22 June 1983 to 20 September 19831984: 8 June 1984 to 15 July 19841986: 7 July 1986 to 7 July 19861987: 24 July 1987 to 17 August 19871988: 15 June 1988 to 15 August 19881989: 26 July 1989 to 26 July 19891991: 28 June 1991 to 23 July 19911993: 7 July 1993 to 28 August 19931994: 19 June 1994 to 21 July 19941995: 19 June 1995 to 1 August 19951997: 17 July 1997 to 17 July 19971999: 7 June 1999 to 18 July 19992001: 25 July 2001 to 9 August 20012002: 4 July 2002 to 18 August 20022005: 25 June 2005 to 13 August 20052006: 18 July 2006 to 3 August 20062007: 26 June 2007 to 8 September 20072008: 9 June 2008 to 19 July 20082009: 18 August 2009 to 18 August 20092010: 4 July 2010 to 2 September 20102011: 12 July 2011 to 22 July 20112012: 20 June 2012 to 17 July 20122013: 24 June 2013 to 11 September 20132015: 8 September 2015 to 8 September 20152016: 15 July 2016 to 14 August 20162017: 18 May 2017 to 13 June 20172018: 3 July 2018 to 6 September 20182019: 6 July 2019 to 19 August 20192020: 19 July 2020 to 28 July 20202021: 7 June 2021 to 26 August 20212022: 24 July 2022 to 9 August 20222024: 19 June 2024 to 1 August 20242025: 24 June 2025 to 29 July 20252026: 19 May 2026 to 3 July 202619361947195919751984199720102020JanFebMarAprMayJunJulAugSepOctNovDec
For each year, a bar from the first to the last day in Boston meeting 35 C (95 F). Long bars mean a long season.
First to last qualifying date each year in Boston
YearFirst dateLast date
19361936-07-081936-07-08
19371937-06-011937-08-21
19391939-09-161939-09-16
19401940-07-261940-07-30
19411941-06-221941-07-02
19431943-06-031943-06-28
19441944-05-311944-08-17
19451945-06-151945-09-07
19461946-07-191946-07-19
19471947-08-131947-08-25
19481948-07-121948-08-28
19491949-06-211949-08-28
19521952-06-261952-07-23
19531953-06-201953-09-02
19541954-07-141954-07-31
19551955-07-021955-08-21
19561956-06-131956-06-15
19571957-06-151957-08-03
19591959-06-101959-08-21
19611961-06-131961-06-13
19631963-06-261963-07-28
19641964-07-011964-07-01
19661966-07-031966-07-03
19681968-07-011968-07-16
19691969-06-271969-09-01
19731973-06-111973-08-30
19741974-07-041974-07-04
19751975-07-311975-08-02
19761976-06-241976-06-24
19771977-07-171977-08-29
19781978-07-211978-07-23
19791979-05-091979-06-16
19801980-06-251980-09-02
19811981-07-081981-07-09
19821982-07-081982-07-19
19831983-06-221983-09-20
19841984-06-081984-07-15
19861986-07-071986-07-07
19871987-07-241987-08-17
19881988-06-151988-08-15
19891989-07-261989-07-26
19911991-06-281991-07-23
19931993-07-071993-08-28
19941994-06-191994-07-21
19951995-06-191995-08-01
19971997-07-171997-07-17
19991999-06-071999-07-18
20012001-07-252001-08-09
20022002-07-042002-08-18
20052005-06-252005-08-13
20062006-07-182006-08-03
20072007-06-262007-09-08
20082008-06-092008-07-19
20092009-08-182009-08-18
20102010-07-042010-09-02
20112011-07-122011-07-22
20122012-06-202012-07-17
20132013-06-242013-09-11
20152015-09-082015-09-08
20162016-07-152016-08-14
20172017-05-182017-06-13
20182018-07-032018-09-06
20192019-07-062019-08-19
20202020-07-192020-07-28
20212021-06-072021-08-26
20222022-07-242022-08-09
20242024-06-192024-08-01
20252025-06-242025-07-29
20262026-05-192026-07-03

Every Year

Days at or above 35 C (95 F) per year in Boston
YearDaysFirst dateLast dateLongest streak in yearCoverage
2026319 May 20263 July 20262 daysIncomplete, not ranked
2025424 June 202529 July 20251 daysComplete
2024519 June 20241 August 20242 daysComplete
2022724 July 20229 August 20226 daysComplete
202187 June 202126 August 20213 daysComplete
2020319 July 202028 July 20202 daysComplete
201956 July 201919 August 20192 daysComplete
201893 July 20186 September 20182 daysComplete
2017318 May 201713 June 20172 daysComplete
2016615 July 201614 August 20162 daysComplete
201518 September 20158 September 20151 daysComplete
2013624 June 201311 September 20132 daysComplete
2012420 June 201217 July 20123 daysComplete
2011312 July 201122 July 20112 daysComplete
201044 July 20102 September 20101 daysComplete
2009118 August 200918 August 20091 daysComplete
200839 June 200819 July 20082 daysComplete
2007526 June 20078 September 20072 daysComplete
2006318 July 20063 August 20062 daysComplete
2005325 June 200513 August 20051 daysComplete
200274 July 200218 August 20022 daysComplete
2001225 July 20019 August 20011 daysComplete
199957 June 199918 July 19993 daysComplete
1997117 July 199717 July 19971 daysComplete
1995419 June 19951 August 19952 daysComplete
1994419 June 199421 July 19942 daysComplete
199367 July 199328 August 19933 daysComplete
1991528 June 199123 July 19912 daysComplete
1989126 July 198926 July 19891 daysComplete
1988715 June 198815 August 19882 daysComplete
1987224 July 198717 August 19871 daysComplete
198617 July 19867 July 19861 daysComplete
198478 June 198415 July 19844 daysComplete
1983922 June 198320 September 19831 daysComplete
198248 July 198219 July 19823 daysComplete
198128 July 19819 July 19812 daysComplete
1980525 June 19802 September 19802 daysComplete
197929 May 197916 June 19791 daysComplete
1978221 July 197823 July 19781 daysComplete
1977617 July 197729 August 19773 daysComplete
1976124 June 197624 June 19761 daysComplete
1975331 July 19752 August 19753 daysComplete
197414 July 19744 July 19741 daysComplete
1973611 June 197330 August 19732 daysComplete
1969327 June 19691 September 19691 daysComplete
196821 July 196816 July 19681 daysComplete
196613 July 19663 July 19661 daysComplete
196411 July 19641 July 19641 daysComplete
1963726 June 196328 July 19633 daysComplete
1961113 June 196113 June 19611 daysComplete
1959510 June 195921 August 19593 daysComplete
1957415 June 19573 August 19571 daysComplete
1956213 June 195615 June 19561 daysComplete
195592 July 195521 August 19552 daysComplete
1954214 July 195431 July 19541 daysComplete
1953820 June 19532 September 19534 daysComplete
1952626 June 195223 July 19523 daysComplete
19491421 June 194928 August 19494 daysComplete
1948512 July 194828 August 19484 daysComplete
1947513 August 194725 August 19473 daysComplete
1946119 July 194619 July 19461 daysComplete
1945315 June 19457 September 19451 daysComplete
19441231 May 194417 August 19447 daysComplete
194333 June 194328 June 19431 daysComplete
1941322 June 19412 July 19411 daysComplete
1940226 July 194030 July 19401 daysComplete
1939116 September 193916 September 19391 daysComplete
193741 June 193721 August 19372 daysComplete
193618 July 19368 July 19361 daysComplete
Decade averages for Days at or above 35 C (95 F) in Boston
DecadeAverage days per yearYears counted
1930s2.03
1940s5.39
1950s5.17
1960s2.56
1970s3.07
1980s4.29
1990s4.26
2000s3.47
2010s4.69
2020s5.45

Compare with your own threshold in the threshold explorer. Fahrenheit thresholds are converted to tenths of a degree Celsius once, rounding half up.

Download the Data

  • Data for Days at or above 35 C (95 F) in Boston, 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). Threshold counts are computed by this site from the threaded city record.

Data as of . Last revised (2026-10-17).