Built 2026-10-19 (19 October 2026)

Days at or above 90 F (32.2 C) in Boston

Boston has had days with a maximum temperature at or above 90 F (32.2 C) in 91 years, most in 1983 with 30. Days per year, season span, streaks and every date.

Key Facts for Boston

  • Boston has had days with a maximum temperature at or above 90 F (32.2 C) in 91 years, 1,208 days in all.
  • The most in one year was 30 days in 1983.
  • In 2026, the latest year on file, there were 16 such days.
  • The earliest first date in a year was 7 April 2010.
  • The latest last date in a year was 12 October 1954.
  • The longest run inside a single year was 8 days in 1944.
  • 1 year with under 90 percent of days observed is left out of these rankings.

Days per Year

91 years, 1,208 days
Days at or above 90 F (32.2 C) per year in Boston Days per year in Boston with a maximum temperature at or above 90 F (32.2 C). The line is the decade average. The most was 30 in 1983. Grey bars are years with under 90 percent of days observed, left out of rankings. 01020301936: 101937: 161938: 101939: 101940: 71941: 181942: 61943: 171944: 211945: 81946: 101947: 101948: 121949: 221950: 81951: 61952: 171953: 151954: 101955: 281956: 111957: 111958: 51959: 221960: 81961: 141962: 51963: 161964: 91965: 91966: 101967: 31968: 101969: 111970: 141971: 151972: 91973: 191974: 71975: 151976: 171977: 181978: 91979: 121980: 221981: 111982: 71983: 301984: 181985: 41986: 41987: 91988: 251989: 71990: 101991: 271992: 21993: 201994: 221995: 171996: 31997: 191998: 81999: 162000: 42001: 162002: 272003: 62004: 42005: 142006: 112007: 182008: 82009: 62010: 252011: 132012: 122013: 182014: 82015: 142016: 222017: 122018: 232019: 152020: 142021: 242022: 212023: 52024: 122025: 192026: 161936194619561966197619861996200620162026
Days per year in Boston with a maximum temperature at or above 90 F (32.2 C). The line is the decade average. The most was 30 in 1983. Grey bars are years with under 90 percent of days observed, left out of rankings.
Days at or above 90 F (32.2 C) per year in Boston
YearDaysDecade average
19361011.5
19371611.5
19381011.5
19391011.5
1940713.1
19411813.1
1942613.1
19431713.1
19442113.1
1945813.1
19461013.1
19471013.1
19481213.1
19492213.1
1950813.3
1951613.3
19521713.3
19531513.3
19541013.3
19552813.3
19561113.3
19571113.3
1958513.3
19592213.3
196089.5
1961149.5
196259.5
1963169.5
196499.5
196599.5
1966109.5
196739.5
1968109.5
1969119.5
19701413.5
19711513.5
1972913.5
19731913.5
1974713.5
19751513.5
19761713.5
19771813.5
1978913.5
19791213.5
19802213.7
19811113.7
1982713.7
19833013.7
19841813.7
1985413.7
1986413.7
1987913.7
19882513.7
1989713.7
19901014.4
19912714.4
1992214.4
19932014.4
19942214.4
19951714.4
1996314.4
19971914.4
1998814.4
19991614.4
2000411.4
20011611.4
20022711.4
2003611.4
2004411.4
20051411.4
20061111.4
20071811.4
2008811.4
2009611.4
20102516.2
20111316.2
20121216.2
20131816.2
2014816.2
20151416.2
20162216.2
20171216.2
20182316.2
20191516.2
20201415.9
20212415.9
20222115.9
2023515.9
20241215.9
20251915.9
20261615.9

Season Span

earliest 7 April, latest 12 October
First to last qualifying date each year in Boston For each year, a bar from the first to the last day in Boston meeting 90 F (32.2 C). Long bars mean a long season. 1936: 18 May 1936 to 8 September 19361937: 31 May 1937 to 4 September 19371938: 21 June 1938 to 16 August 19381939: 28 May 1939 to 16 September 19391940: 13 June 1940 to 31 July 19401941: 22 May 1941 to 16 September 19411942: 13 June 1942 to 2 September 19421943: 3 June 1943 to 23 August 19431944: 31 May 1944 to 2 September 19441945: 15 June 1945 to 8 September 19451946: 24 June 1946 to 9 August 19461947: 30 July 1947 to 26 August 19471948: 30 June 1948 to 13 September 19481949: 19 May 1949 to 28 August 19491950: 8 June 1950 to 31 July 19501951: 16 May 1951 to 12 September 19511952: 15 June 1952 to 13 September 19521953: 6 June 1953 to 2 September 19531954: 20 June 1954 to 12 October 19541955: 18 June 1955 to 18 September 19551956: 31 May 1956 to 28 August 19561957: 15 June 1957 to 13 September 19571958: 1 July 1958 to 7 August 19581959: 22 May 1959 to 24 September 19591960: 27 June 1960 to 8 September 19601961: 13 June 1961 to 12 September 19611962: 27 April 1962 to 29 June 19621963: 24 June 1963 to 7 October 19631964: 23 May 1964 to 28 July 19641965: 26 May 1965 to 16 August 19651966: 27 June 1966 to 2 September 19661967: 10 June 1967 to 17 June 19671968: 6 June 1968 to 25 August 19681969: 13 June 1969 to 1 September 19691970: 10 May 1970 to 23 September 19701971: 20 June 1971 to 9 September 19711972: 2 July 1972 to 25 July 19721973: 9 June 1973 to 4 September 19731974: 9 June 1974 to 14 August 19741975: 20 May 1975 to 14 August 19751976: 18 April 1976 to 21 August 19761977: 17 May 1977 to 2 September 19771978: 10 July 1978 to 29 August 19781979: 9 May 1979 to 5 August 19791980: 24 June 1980 to 22 September 19801981: 25 May 1981 to 14 September 19811982: 7 July 1982 to 19 July 19821983: 12 June 1983 to 20 September 19831984: 8 June 1984 to 16 August 19841985: 20 July 1985 to 4 September 19851986: 19 May 1986 to 25 July 19861987: 30 May 1987 to 18 August 19871988: 13 June 1988 to 15 August 19881989: 27 June 1989 to 5 August 19891990: 27 April 1990 to 18 August 19901991: 24 May 1991 to 16 September 19911992: 23 May 1992 to 11 August 19921993: 11 May 1993 to 15 September 19931994: 17 June 1994 to 14 August 19941995: 1 June 1995 to 21 August 19951996: 20 May 1996 to 23 August 19961997: 10 June 1997 to 17 August 19971998: 14 July 1998 to 24 August 19981999: 7 June 1999 to 17 August 19992000: 7 May 2000 to 27 June 20002001: 2 May 2001 to 10 August 20012002: 17 April 2002 to 10 September 20022003: 27 June 2003 to 22 August 20032004: 9 June 2004 to 28 August 20042005: 13 June 2005 to 12 September 20052006: 18 June 2006 to 3 August 20062007: 25 May 2007 to 26 September 20072008: 7 June 2008 to 19 July 20082009: 28 April 2009 to 21 August 20092010: 7 April 2010 to 2 September 20102011: 9 June 2011 to 2 August 20112012: 20 June 2012 to 31 August 20122013: 31 May 2013 to 11 September 20132014: 2 July 2014 to 6 September 20142015: 19 July 2015 to 9 September 20152016: 28 May 2016 to 14 September 20162017: 17 May 2017 to 22 August 20172018: 3 May 2018 to 6 September 20182019: 5 July 2019 to 23 September 20192020: 20 June 2020 to 12 August 20202021: 23 May 2021 to 27 August 20212022: 26 June 2022 to 30 August 20222023: 12 July 2023 to 7 September 20232024: 18 June 2024 to 28 August 20242025: 19 June 2025 to 17 August 20252026: 17 May 2026 to 9 August 202619361948196019721984199620082020JanFebMarAprMayJunJulAugSepOctNovDec
For each year, a bar from the first to the last day in Boston meeting 90 F (32.2 C). Long bars mean a long season.
First to last qualifying date each year in Boston
YearFirst dateLast date
19361936-05-181936-09-08
19371937-05-311937-09-04
19381938-06-211938-08-16
19391939-05-281939-09-16
19401940-06-131940-07-31
19411941-05-221941-09-16
19421942-06-131942-09-02
19431943-06-031943-08-23
19441944-05-311944-09-02
19451945-06-151945-09-08
19461946-06-241946-08-09
19471947-07-301947-08-26
19481948-06-301948-09-13
19491949-05-191949-08-28
19501950-06-081950-07-31
19511951-05-161951-09-12
19521952-06-151952-09-13
19531953-06-061953-09-02
19541954-06-201954-10-12
19551955-06-181955-09-18
19561956-05-311956-08-28
19571957-06-151957-09-13
19581958-07-011958-08-07
19591959-05-221959-09-24
19601960-06-271960-09-08
19611961-06-131961-09-12
19621962-04-271962-06-29
19631963-06-241963-10-07
19641964-05-231964-07-28
19651965-05-261965-08-16
19661966-06-271966-09-02
19671967-06-101967-06-17
19681968-06-061968-08-25
19691969-06-131969-09-01
19701970-05-101970-09-23
19711971-06-201971-09-09
19721972-07-021972-07-25
19731973-06-091973-09-04
19741974-06-091974-08-14
19751975-05-201975-08-14
19761976-04-181976-08-21
19771977-05-171977-09-02
19781978-07-101978-08-29
19791979-05-091979-08-05
19801980-06-241980-09-22
19811981-05-251981-09-14
19821982-07-071982-07-19
19831983-06-121983-09-20
19841984-06-081984-08-16
19851985-07-201985-09-04
19861986-05-191986-07-25
19871987-05-301987-08-18
19881988-06-131988-08-15
19891989-06-271989-08-05
19901990-04-271990-08-18
19911991-05-241991-09-16
19921992-05-231992-08-11
19931993-05-111993-09-15
19941994-06-171994-08-14
19951995-06-011995-08-21
19961996-05-201996-08-23
19971997-06-101997-08-17
19981998-07-141998-08-24
19991999-06-071999-08-17
20002000-05-072000-06-27
20012001-05-022001-08-10
20022002-04-172002-09-10
20032003-06-272003-08-22
20042004-06-092004-08-28
20052005-06-132005-09-12
20062006-06-182006-08-03
20072007-05-252007-09-26
20082008-06-072008-07-19
20092009-04-282009-08-21
20102010-04-072010-09-02
20112011-06-092011-08-02
20122012-06-202012-08-31
20132013-05-312013-09-11
20142014-07-022014-09-06
20152015-07-192015-09-09
20162016-05-282016-09-14
20172017-05-172017-08-22
20182018-05-032018-09-06
20192019-07-052019-09-23
20202020-06-202020-08-12
20212021-05-232021-08-27
20222022-06-262022-08-30
20232023-07-122023-09-07
20242024-06-182024-08-28
20252025-06-192025-08-17
20262026-05-172026-08-09

Every Year

Days at or above 90 F (32.2 C) per year in Boston
YearDaysFirst dateLast dateLongest streak in yearCoverage
20261617 May 20269 August 20264 daysIncomplete, not ranked
20251919 June 202517 August 20254 daysComplete
20241218 June 202428 August 20243 daysComplete
2023512 July 20237 September 20232 daysComplete
20222126 June 202230 August 20227 daysComplete
20212423 May 202127 August 20215 daysComplete
20201420 June 202012 August 20204 daysComplete
2019155 July 201923 September 20194 daysComplete
2018233 May 20186 September 20184 daysComplete
20171217 May 201722 August 20173 daysComplete
20162228 May 201614 September 20166 daysComplete
20151419 July 20159 September 20153 daysComplete
201482 July 20146 September 20142 daysComplete
20131831 May 201311 September 20137 daysComplete
20121220 June 201231 August 20123 daysComplete
2011139 June 20112 August 20114 daysComplete
2010257 April 20102 September 20105 daysComplete
2009628 April 200921 August 20093 daysComplete
200887 June 200819 July 20084 daysComplete
20071825 May 200726 September 20073 daysComplete
20061118 June 20063 August 20063 daysComplete
20051413 June 200512 September 20052 daysComplete
200449 June 200428 August 20041 daysComplete
2003627 June 200322 August 20032 daysComplete
20022717 April 200210 September 20028 daysComplete
2001162 May 200110 August 20013 daysComplete
200047 May 200027 June 20001 daysComplete
1999167 June 199917 August 19994 daysComplete
1998814 July 199824 August 19983 daysComplete
19971910 June 199717 August 19973 daysComplete
1996320 May 199623 August 19962 daysComplete
1995171 June 199521 August 19954 daysComplete
19942217 June 199414 August 19948 daysComplete
19932011 May 199315 September 19934 daysComplete
1992223 May 199211 August 19921 daysComplete
19912724 May 199116 September 19916 daysComplete
19901027 April 199018 August 19905 daysComplete
1989727 June 19895 August 19893 daysComplete
19882513 June 198815 August 19887 daysComplete
1987930 May 198718 August 19874 daysComplete
1986419 May 198625 July 19862 daysComplete
1985420 July 19854 September 19852 daysComplete
1984188 June 198416 August 19844 daysComplete
19833012 June 198320 September 19837 daysComplete
198277 July 198219 July 19824 daysComplete
19811125 May 198114 September 19813 daysComplete
19802224 June 198022 September 19804 daysComplete
1979129 May 19795 August 19794 daysComplete
1978910 July 197829 August 19785 daysComplete
19771817 May 19772 September 19776 daysComplete
19761718 April 197621 August 19765 daysComplete
19751520 May 197514 August 19753 daysComplete
197479 June 197414 August 19742 daysComplete
1973199 June 19734 September 19735 daysComplete
197292 July 197225 July 19724 daysComplete
19711520 June 19719 September 19714 daysComplete
19701410 May 197023 September 19704 daysComplete
19691113 June 19691 September 19693 daysComplete
1968106 June 196825 August 19683 daysComplete
1967310 June 196717 June 19672 daysComplete
19661027 June 19662 September 19663 daysComplete
1965926 May 196516 August 19652 daysComplete
1964923 May 196428 July 19642 daysComplete
19631624 June 19637 October 19636 daysComplete
1962527 April 196229 June 19622 daysComplete
19611413 June 196112 September 19613 daysComplete
1960827 June 19608 September 19602 daysComplete
19592222 May 195924 September 19594 daysComplete
195851 July 19587 August 19582 daysComplete
19571115 June 195713 September 19572 daysComplete
19561131 May 195628 August 19562 daysComplete
19552818 June 195518 September 19554 daysComplete
19541020 June 195412 October 19543 daysComplete
1953156 June 19532 September 19534 daysComplete
19521715 June 195213 September 19524 daysComplete
1951616 May 195112 September 19511 daysComplete
195088 June 195031 July 19502 daysComplete
19492219 May 194928 August 19494 daysComplete
19481230 June 194813 September 19485 daysComplete
19471030 July 194726 August 19474 daysComplete
19461024 June 19469 August 19464 daysComplete
1945815 June 19458 September 19452 daysComplete
19442131 May 19442 September 19448 daysComplete
1943173 June 194323 August 19432 daysComplete
1942613 June 19422 September 19422 daysComplete
19411822 May 194116 September 19414 daysComplete
1940713 June 194031 July 19402 daysComplete
19391028 May 193916 September 19392 daysComplete
19381021 June 193816 August 19384 daysComplete
19371631 May 19374 September 19372 daysComplete
19361018 May 19368 September 19361 daysComplete
Decade averages for Days at or above 90 F (32.2 C) in Boston
DecadeAverage days per yearYears counted
1930s11.54
1940s13.110
1950s13.310
1960s9.510
1970s13.510
1980s13.710
1990s14.410
2000s11.410
2010s16.210
2020s15.86

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 90 F (32.2 C) 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).