Somerville Dam Threshold Days by Year (USC00418446)
17 fixed thresholds counted per year at Somerville Dam (USC00418446): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Somerville Dam Thresholds
- Somerville Dam: days with 10 mm (0.39 in) or more of precipitation in 50 years, most in 1991 with 44.
- Somerville Dam: days with 25 mm (0.98 in) or more of precipitation in 50 years, most in 2004 with 22.
- Somerville Dam: days with a maximum temperature at or above 30 C (86 F) in 49 years, most in 2011 with 184.
- Somerville Dam: days with a maximum temperature at or above 35 C (95 F) in 49 years, most in 2011 with 124.
- 17 fixed thresholds have at least one qualifying day at Somerville Dam.
Days at or above 30 C (86 F)
49 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1966 | 119 | 129.5 |
| 1967 | 145 | 129.5 |
| 1968 | 119 | 129.5 |
| 1969 | 135 | 129.5 |
| 1970 | 114 | 127.9 |
| 1971 | 143 | 127.9 |
| 1972 | 152 | 127.9 |
| 1973 | 136 | 127.9 |
| 1974 | 116 | 127.9 |
| 1975 | 121 | 127.9 |
| 1976 | 114 | 127.9 |
| 1977 | 140 | 127.9 |
| 1978 | 129 | 127.9 |
| 1979 | 114 | 127.9 |
| 1980 | 132 | 134.2 |
| 1981 | 127 | 134.2 |
| 1982 | 136 | 134.2 |
| 1983 | 115 | 134.2 |
| 1984 | 142 | 134.2 |
| 1985 | 135 | 134.2 |
| 1986 | 134 | 134.2 |
| 1987 | 134 | 134.2 |
| 1988 | 150 | 134.2 |
| 1989 | 137 | 134.2 |
| 1990 | 148 | 137.9 |
| 1991 | 142 | 137.9 |
| 1992 | 133 | 137.9 |
| 1993 | 137 | 137.9 |
| 1994 | 141 | 137.9 |
| 1995 | 120 | 137.9 |
| 1996 | 155 | 137.9 |
| 1997 | 137 | 137.9 |
| 1998 | 128 | 137.9 |
| 2000 | 159 | 155.8 |
| 2001 | 136 | 155.8 |
| 2003 | 152 | 155.8 |
| 2004 | 149 | 155.8 |
| 2005 | 168 | 155.8 |
| 2006 | 174 | 155.8 |
| 2007 | 154 | 155.8 |
| 2008 | 160 | 155.8 |
| 2009 | 150 | 155.8 |
| 2010 | 169 | 165 |
| 2011 | 184 | 165 |
| 2013 | 149 | 165 |
| 2014 | 157 | 165 |
| 2015 | 159 | 165 |
| 2016 | 172 | 165 |
| 2026 | 148 | 148 |
| Year | First date | Last date |
|---|---|---|
| 1966 | 1966-04-04 | 1966-11-19 |
| 1967 | 1967-03-12 | 1967-10-11 |
| 1968 | 1968-05-16 | 1968-10-17 |
| 1969 | 1969-05-21 | 1969-11-10 |
| 1970 | 1970-04-30 | 1970-10-08 |
| 1971 | 1971-03-14 | 1971-10-20 |
| 1972 | 1972-03-18 | 1972-10-19 |
| 1973 | 1973-05-09 | 1973-11-09 |
| 1974 | 1974-03-20 | 1974-10-11 |
| 1975 | 1975-04-25 | 1975-10-25 |
| 1976 | 1976-05-07 | 1976-10-05 |
| 1977 | 1977-05-18 | 1977-11-01 |
| 1978 | 1978-04-19 | 1978-10-21 |
| 1979 | 1979-05-31 | 1979-10-22 |
| 1980 | 1980-03-11 | 1980-10-28 |
| 1981 | 1981-04-21 | 1981-10-18 |
| 1982 | 1982-04-01 | 1982-10-07 |
| 1983 | 1983-05-08 | 1983-10-19 |
| 1984 | 1984-03-28 | 1984-11-02 |
| 1985 | 1985-04-17 | 1985-10-25 |
| 1986 | 1986-02-20 | 1986-11-19 |
| 1987 | 1987-04-16 | 1987-11-05 |
| 1988 | 1988-04-04 | 1988-11-10 |
| 1989 | 1989-03-31 | 1989-11-09 |
| 1990 | 1990-04-30 | 1990-10-17 |
| 1991 | 1991-03-07 | 1991-10-30 |
| 1992 | 1992-04-25 | 1992-11-01 |
| 1993 | 1993-04-26 | 1993-10-20 |
| 1994 | 1994-04-27 | 1994-10-23 |
| 1995 | 1995-03-24 | 1995-10-28 |
| 1996 | 1996-02-22 | 1996-10-18 |
| 1997 | 1997-03-23 | 1997-11-01 |
| 1998 | 1998-03-30 | 1998-11-26 |
| 2000 | 2000-01-03 | 2000-10-31 |
| 2001 | 2001-05-02 | 2001-11-05 |
| 2003 | 2003-03-15 | 2003-11-18 |
| 2004 | 2004-05-17 | 2004-10-31 |
| 2005 | 2005-03-31 | 2005-11-25 |
| 2006 | 2006-03-12 | 2006-11-11 |
| 2007 | 2007-04-29 | 2007-11-15 |
| 2008 | 2008-03-15 | 2008-10-27 |
| 2009 | 2009-02-28 | 2009-10-30 |
| 2010 | 2010-04-24 | 2010-11-11 |
| 2011 | 2011-03-19 | 2011-11-21 |
| 2013 | 2013-03-19 | 2013-11-18 |
| 2014 | 2014-04-23 | 2014-10-29 |
| 2015 | 2015-04-14 | 2015-10-23 |
| 2016 | 2016-03-15 | 2016-11-17 |
| 2026 | 2026-01-02 | 2026-10-15 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 49 | 184 | 2011 | 148 |
| 35 C (95 F): Days | 49 | 124 | 2011 | 60 |
| 40 C (104 F): Days | 22 | 41 | 2011 | 1 |
| 45 C (113 F): Days | 1 | 1 | 2000 | 1 |
| 90 F (32.2 C): Days | 49 | 154 | 2011 | 101 |
| 100 F (37.8 C): Days | 41 | 82 | 2011 | 13 |
| 110 F (43.3 C): Days | 2 | 3 | 2000 | 3 |
| 0 C (32 F): Ice days (max | 23 | 6 | 1983 | 1 |
| 0 C (32 F): Frost days (min | 44 | 74 | 2010 | 3 |
| -10 C (14 F): Days with min | 10 | 6 | 1983 | 2 |
| 20 C (68 F): Tropical nights (min | 44 | 145 | 1986 | 146 |
| 25 C (77 F): Days with min | 37 | 38 | 1980 | 31 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 50 | 44 | 1991 | 15 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 50 | 22 | 2004 | 5 |
| 50 mm (1.97 in): Days with 50 mm or more rain | 45 | 8 | 1968 | 4 |
| 100 mm (3.94 in): Days with 100 mm or more rain | 13 | 3 | 2015 | 2 |
| 200 mm (7.87 in): Days with 200 mm or more rain | 2 | 1 | 1994 | 1 |
Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1966.
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.
Data as of . Last revised (2026-10-17).