Rockville 1 NE Threshold Days by Year (USC00187705)
18 fixed thresholds counted per year at Rockville 1 NE (USC00187705): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Rockville 1 NE Thresholds
- Rockville 1 NE: days with 10 mm (0.39 in) or more of precipitation in 60 years, most in 1979 with 55.
- Rockville 1 NE: days with 25 mm (0.98 in) or more of precipitation in 60 years, most in 1972 with 22.
- Rockville 1 NE: days with a maximum temperature at or above 30 C (86 F) in 59 years, most in 1959 with 92.
- Rockville 1 NE: days with a maximum temperature at or above 90 F (32.2 C) in 58 years, most in 1914 with 55.
- 18 fixed thresholds have at least one qualifying day at Rockville 1 NE.
Days at or above 30 C (86 F)
59 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1908 | 25 | 22 |
| 1909 | 19 | 22 |
| 1912 | 21 | 48.4 |
| 1914 | 81 | 48.4 |
| 1915 | 52 | 48.4 |
| 1916 | 46 | 48.4 |
| 1917 | 34 | 48.4 |
| 1918 | 48 | 48.4 |
| 1919 | 57 | 48.4 |
| 1920 | 38 | 38 |
| 1949 | 43 | 43 |
| 1950 | 20 | 62.5 |
| 1951 | 55 | 62.5 |
| 1952 | 56 | 62.5 |
| 1953 | 61 | 62.5 |
| 1954 | 66 | 62.5 |
| 1955 | 73 | 62.5 |
| 1956 | 60 | 62.5 |
| 1957 | 83 | 62.5 |
| 1958 | 59 | 62.5 |
| 1959 | 92 | 62.5 |
| 1960 | 51 | 57.7 |
| 1961 | 70 | 57.7 |
| 1962 | 57 | 57.7 |
| 1964 | 68 | 57.7 |
| 1965 | 64 | 57.7 |
| 1967 | 36 | 57.7 |
| 1971 | 54 | 56.3 |
| 1972 | 46 | 56.3 |
| 1973 | 62 | 56.3 |
| 1974 | 55 | 56.3 |
| 1975 | 57 | 56.3 |
| 1976 | 43 | 56.3 |
| 1977 | 77 | 56.3 |
| 1978 | 65 | 56.3 |
| 1979 | 48 | 56.3 |
| 1980 | 78 | 56.9 |
| 1982 | 40 | 56.9 |
| 1985 | 41 | 56.9 |
| 1986 | 70 | 56.9 |
| 1987 | 81 | 56.9 |
| 1988 | 61 | 56.9 |
| 1989 | 27 | 56.9 |
| 1990 | 27 | 47.5 |
| 1991 | 70 | 47.5 |
| 1992 | 30 | 47.5 |
| 1993 | 57 | 47.5 |
| 1994 | 51 | 47.5 |
| 1995 | 54 | 47.5 |
| 1996 | 27 | 47.5 |
| 1997 | 44 | 47.5 |
| 1998 | 57 | 47.5 |
| 1999 | 58 | 47.5 |
| 2000 | 35 | 46.2 |
| 2001 | 37 | 46.2 |
| 2002 | 66 | 46.2 |
| 2003 | 36 | 46.2 |
| 2005 | 46 | 46.2 |
| 2006 | 57 | 46.2 |
| Year | First date | Last date |
|---|---|---|
| 1908 | 1908-04-24 | 1908-08-14 |
| 1909 | 1909-04-19 | 1909-08-25 |
| 1912 | 1912-05-24 | 1912-09-11 |
| 1914 | 1914-04-19 | 1914-10-10 |
| 1915 | 1915-04-19 | 1915-09-17 |
| 1916 | 1916-05-08 | 1916-10-09 |
| 1917 | 1917-04-21 | 1917-09-02 |
| 1918 | 1918-05-05 | 1918-08-30 |
| 1919 | 1919-05-04 | 1919-10-11 |
| 1920 | 1920-06-02 | 1920-10-15 |
| 1949 | 1949-05-05 | 1949-09-05 |
| 1950 | 1950-05-06 | 1950-09-03 |
| 1951 | 1951-06-01 | 1951-10-06 |
| 1952 | 1952-04-23 | 1952-09-15 |
| 1953 | 1953-04-25 | 1953-09-30 |
| 1954 | 1954-05-02 | 1954-10-14 |
| 1955 | 1955-05-05 | 1955-09-21 |
| 1956 | 1956-04-28 | 1956-09-23 |
| 1957 | 1957-05-09 | 1957-09-23 |
| 1958 | 1958-05-18 | 1958-10-10 |
| 1959 | 1959-04-08 | 1959-10-07 |
| 1960 | 1960-04-14 | 1960-09-09 |
| 1961 | 1961-04-25 | 1961-09-26 |
| 1962 | 1962-04-26 | 1962-10-13 |
| 1964 | 1964-05-08 | 1964-09-18 |
| 1965 | 1965-05-03 | 1965-09-23 |
| 1967 | 1967-06-09 | 1967-10-06 |
| 1971 | 1971-05-19 | 1971-09-11 |
| 1972 | 1972-06-03 | 1972-09-26 |
| 1973 | 1973-04-22 | 1973-09-28 |
| 1974 | 1974-04-29 | 1974-09-03 |
| 1975 | 1975-05-20 | 1975-08-30 |
| 1976 | 1976-04-16 | 1976-09-14 |
| 1977 | 1977-04-11 | 1977-09-19 |
| 1978 | 1978-04-01 | 1978-09-21 |
| 1979 | 1979-03-31 | 1979-09-05 |
| 1980 | 1980-05-05 | 1980-09-23 |
| 1982 | 1982-05-07 | 1982-09-02 |
| 1985 | 1985-03-28 | 1985-09-10 |
| 1986 | 1986-03-30 | 1986-10-02 |
| 1987 | 1987-04-22 | 1987-09-15 |
| 1988 | 1988-05-23 | 1988-09-23 |
| 1989 | 1989-06-01 | 1989-09-11 |
| 1990 | 1990-04-26 | 1990-09-07 |
| 1991 | 1991-04-08 | 1991-09-18 |
| 1992 | 1992-05-02 | 1992-08-28 |
| 1993 | 1993-05-11 | 1993-09-15 |
| 1994 | 1994-04-25 | 1994-09-17 |
| 1995 | 1995-04-19 | 1995-09-13 |
| 1996 | 1996-04-22 | 1996-09-07 |
| 1997 | 1997-05-19 | 1997-09-07 |
| 1998 | 1998-03-30 | 1998-09-27 |
| 1999 | 1999-05-12 | 1999-09-07 |
| 2000 | 2000-05-06 | 2000-09-20 |
| 2001 | 2001-04-09 | 2001-08-27 |
| 2002 | 2002-04-16 | 2002-09-21 |
| 2003 | 2003-06-12 | 2003-08-29 |
| 2005 | 2005-06-06 | 2005-09-22 |
| 2006 | 2006-05-29 | 2006-08-29 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 59 | 92 | 1959 | 57 |
| 35 C (95 F): Days | 44 | 23 | 1914 | 6 |
| 40 C (104 F): Days | 2 | 2 | 1918 | 1 |
| 90 F (32.2 C): Days | 58 | 55 | 1914 | 34 |
| 100 F (37.8 C): Days | 11 | 3 | 1914 | 1 |
| 0 C (32 F): Ice days (max | 58 | 27 | 1918 | 4 |
| 0 C (32 F): Frost days (min | 57 | 145 | 1917 | 62 |
| -10 C (14 F): Days with min | 55 | 36 | 1977 | 1 |
| -20 C (-4 F): Days with min | 11 | 5 | 1979 | 1 |
| 20 C (68 F): Tropical nights (min | 57 | 71 | 1987 | 49 |
| 25 C (77 F): Days with min | 21 | 12 | 1987 | 3 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 60 | 55 | 1979 | 33 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 60 | 22 | 1972 | 10 |
| 50 mm (1.97 in): Days with 50 mm or more rain | 47 | 4 | 1952 | 3 |
| 100 mm (3.94 in): Days with 100 mm or more rain | 10 | 2 | 1952 | 2 |
| 200 mm (7.87 in): Days with 200 mm or more rain | 1 | 1 | 1972 | 1 |
| 10 cm (3.9 in): Days with 10 cm or more snowfall | 38 | 6 | 1996 | 3 |
| 25 cm (9.8 in): Days with 25 cm or more snowfall | 7 | 2 | 1967 | 1 |
Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1908.
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 (2025-12-31).