Nights at or below -20 C (-4 F) in Boston
Boston has had nights with a minimum temperature at or below -20 C (-4 F) in 17 years, most in 1942 with 3. Days per year, season span, streaks and every date.
Key Facts for Boston
- Boston has had nights with a minimum temperature at or below -20 C (-4 F) in 17 years, 27 days in all.
- The most in one year was 3 days in 1942.
- In 2023, the latest year on file, there were 2 such days.
- The earliest first date in a year was 4 January 1981.
- The latest last date in a year was 31 December 1962.
- The longest run inside a single year was 3 days in 1942.
- 1 year with under 90 percent of days observed is left out of these rankings.
Days per Year
17 years, 27 days| Year | Days | Decade average |
|---|---|---|
| 1942 | 3 | 2 |
| 1943 | 2 | 2 |
| 1945 | 1 | 2 |
| 1957 | 2 | 1.5 |
| 1958 | 1 | 1.5 |
| 1961 | 1 | 1.3 |
| 1962 | 1 | 1.3 |
| 1965 | 1 | 1.3 |
| 1968 | 2 | 1.3 |
| 1976 | 1 | 1 |
| 1980 | 2 | 1.7 |
| 1981 | 2 | 1.7 |
| 1988 | 1 | 1.7 |
| 1994 | 1 | 1 |
| 2004 | 3 | 3 |
| 2016 | 1 | 1 |
| 2023 | 2 | 2 |
Season Span
earliest 4 January, latest 31 December| Year | First date | Last date |
|---|---|---|
| 1942 | 1942-12-19 | 1942-12-21 |
| 1943 | 1943-02-15 | 1943-02-16 |
| 1945 | 1945-01-25 | 1945-01-25 |
| 1957 | 1957-01-14 | 1957-01-15 |
| 1958 | 1958-02-18 | 1958-02-18 |
| 1961 | 1961-02-02 | 1961-02-02 |
| 1962 | 1962-12-31 | 1962-12-31 |
| 1965 | 1965-01-15 | 1965-01-15 |
| 1968 | 1968-01-08 | 1968-01-09 |
| 1976 | 1976-01-23 | 1976-01-23 |
| 1980 | 1980-12-25 | 1980-12-26 |
| 1981 | 1981-01-04 | 1981-01-05 |
| 1988 | 1988-01-14 | 1988-01-14 |
| 1994 | 1994-01-16 | 1994-01-16 |
| 2004 | 2004-01-14 | 2004-01-16 |
| 2016 | 2016-02-14 | 2016-02-14 |
| 2023 | 2023-02-03 | 2023-02-04 |
Every Year
| Year | Days | First date | Last date | Longest streak in year | Coverage |
|---|---|---|---|---|---|
| 2023 | 2 | 3 February 2023 | 4 February 2023 | 2 days | Complete |
| 2016 | 1 | 14 February 2016 | 14 February 2016 | 1 days | Complete |
| 2004 | 3 | 14 January 2004 | 16 January 2004 | 3 days | Complete |
| 1994 | 1 | 16 January 1994 | 16 January 1994 | 1 days | Complete |
| 1988 | 1 | 14 January 1988 | 14 January 1988 | 1 days | Complete |
| 1981 | 2 | 4 January 1981 | 5 January 1981 | 2 days | Complete |
| 1980 | 2 | 25 December 1980 | 26 December 1980 | 2 days | Complete |
| 1976 | 1 | 23 January 1976 | 23 January 1976 | 1 days | Complete |
| 1968 | 2 | 8 January 1968 | 9 January 1968 | 2 days | Complete |
| 1965 | 1 | 15 January 1965 | 15 January 1965 | 1 days | Complete |
| 1962 | 1 | 31 December 1962 | 31 December 1962 | 1 days | Complete |
| 1961 | 1 | 2 February 1961 | 2 February 1961 | 1 days | Complete |
| 1958 | 1 | 18 February 1958 | 18 February 1958 | 1 days | Complete |
| 1957 | 2 | 14 January 1957 | 15 January 1957 | 2 days | Complete |
| 1945 | 1 | 25 January 1945 | 25 January 1945 | 1 days | Complete |
| 1943 | 2 | 15 February 1943 | 16 February 1943 | 2 days | Complete |
| 1942 | 3 | 19 December 1942 | 21 December 1942 | 3 days | Complete |
| Decade | Average days per year | Years counted |
|---|---|---|
| 1940s | 2.0 | 3 |
| 1950s | 1.5 | 2 |
| 1960s | 1.3 | 4 |
| 1970s | 1.0 | 1 |
| 1980s | 1.7 | 3 |
| 1990s | 1.0 | 1 |
| 2000s | 3.0 | 1 |
| 2010s | 1.0 | 1 |
| 2020s | 2.0 | 1 |
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
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).