Keystone Dam Threshold Days by Year
18 fixed thresholds counted per year at Keystone Dam (USC00344812): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Keystone Dam Thresholds
- Keystone Dam: days with 10 mm (0.39 in) or more of precipitation in 34 years, most in 1973 with 43.
- Keystone Dam: days with 25 mm (0.98 in) or more of precipitation in 34 years, most in 1974 with 19.
- Keystone Dam: days with 50 mm (1.97 in) or more of precipitation in 29 years, most in 1974 with 8.
- Keystone Dam: days with a maximum temperature at or above 30 C (86 F) in 15 years, most in 1977 with 111.
- 18 fixed thresholds have at least one qualifying day at Keystone Dam.
Days at or above 30 C (86 F)
15 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1966 | 90 | 89.3 |
| 1967 | 80 | 89.3 |
| 1969 | 98 | 89.3 |
| 1970 | 87 | 94.9 |
| 1971 | 103 | 94.9 |
| 1972 | 99 | 94.9 |
| 1973 | 91 | 94.9 |
| 1974 | 77 | 94.9 |
| 1975 | 102 | 94.9 |
| 1976 | 89 | 94.9 |
| 1977 | 111 | 94.9 |
| 1986 | 97 | 97 |
| 1990 | 92 | 78.7 |
| 1992 | 61 | 78.7 |
| 1996 | 83 | 78.7 |
| Year | First date | Last date |
|---|---|---|
| 1966 | 1966-04-01 | 1966-10-14 |
| 1967 | 1967-03-11 | 1967-10-07 |
| 1969 | 1969-05-22 | 1969-10-11 |
| 1970 | 1970-04-28 | 1970-10-03 |
| 1971 | 1971-03-14 | 1971-10-02 |
| 1972 | 1972-04-07 | 1972-10-13 |
| 1973 | 1973-05-10 | 1973-10-25 |
| 1974 | 1974-04-01 | 1974-09-12 |
| 1975 | 1975-04-18 | 1975-10-21 |
| 1976 | 1976-05-30 | 1976-10-12 |
| 1977 | 1977-04-09 | 1977-10-28 |
| 1986 | 1986-03-31 | 1986-09-29 |
| 1990 | 1990-05-20 | 1990-10-07 |
| 1992 | 1992-03-01 | 1992-10-14 |
| 1996 | 1996-02-23 | 1996-10-02 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 15 | 111 | 1977 | 83 |
| 35 C (95 F): Days | 15 | 45 | 1977 | 13 |
| 40 C (104 F): Days | 9 | 5 | 1986 | 1 |
| 90 F (32.2 C): Days | 15 | 78 | 1977 | 46 |
| 100 F (37.8 C): Days | 13 | 16 | 1970 | 3 |
| 110 F (43.3 C): Days | 1 | 2 | 1986 | 2 |
| 0 C (32 F): Ice days (max | 15 | 16 | 1972 | 14 |
| 0 C (32 F): Frost days (min | 14 | 107 | 1976 | 92 |
| -10 C (14 F): Days with min | 14 | 24 | 1977 | 20 |
| -20 C (-4 F): Days with min | 3 | 2 | 1996 | 2 |
| 20 C (68 F): Tropical nights (min | 14 | 75 | 1990 | 44 |
| 25 C (77 F): Days with min | 9 | 9 | 1966 | 2 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 34 | 43 | 1973 | 25 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 34 | 19 | 1974 | 12 |
| 50 mm (1.97 in): Days with 50 mm or more rain | 29 | 8 | 1974 | 4 |
| 100 mm (3.94 in): Days with 100 mm or more rain | 8 | 1 | 1971 | 1 |
| 10 cm (3.9 in): Days with 10 cm or more snowfall | 8 | 1 | 1972 | 1 |
| 25 cm (9.8 in): Days with 25 cm or more snowfall | 1 | 0 | n/a | 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 (2025-12-31).