Lower Monumental Dam Threshold Days by Year
14 fixed thresholds counted per year at Lower Monumental Dam (USC00454841): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Lower Monumental Dam Thresholds
- Lower Monumental Dam: days with a maximum temperature at or above 30 C (86 F) in 15 years, most in 1967 with 98.
- Lower Monumental Dam: days with a maximum temperature at or above 35 C (95 F) in 15 years, most in 1967 with 49.
- Lower Monumental Dam: days with a maximum temperature at or above 90 F (32.2 C) in 15 years, most in 1967 with 76.
- Lower Monumental Dam: days with a maximum temperature at or above 100 F (37.8 C) in 15 years, most in 1971 with 26.
- 14 fixed thresholds have at least one qualifying day at Lower Monumental Dam.
Days at or above 30 C (86 F)
15 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1963 | 76 | 69.3 |
| 1964 | 48 | 69.3 |
| 1965 | 56 | 69.3 |
| 1966 | 77 | 69.3 |
| 1967 | 98 | 69.3 |
| 1968 | 50 | 69.3 |
| 1969 | 80 | 69.3 |
| 1970 | 72 | 63 |
| 1971 | 62 | 63 |
| 1972 | 47 | 63 |
| 1973 | 70 | 63 |
| 1974 | 70 | 63 |
| 1976 | 59 | 63 |
| 1977 | 71 | 63 |
| 1978 | 53 | 63 |
| Year | First date | Last date |
|---|---|---|
| 1963 | 1963-05-19 | 1963-10-16 |
| 1964 | 1964-05-17 | 1964-09-25 |
| 1965 | 1965-05-12 | 1965-10-02 |
| 1966 | 1966-05-03 | 1966-09-23 |
| 1967 | 1967-05-17 | 1967-09-29 |
| 1968 | 1968-04-29 | 1968-09-26 |
| 1969 | 1969-05-08 | 1969-09-18 |
| 1970 | 1970-05-17 | 1970-10-03 |
| 1971 | 1971-05-03 | 1971-09-11 |
| 1972 | 1972-05-14 | 1972-09-17 |
| 1973 | 1973-05-14 | 1973-09-14 |
| 1974 | 1974-06-11 | 1974-09-26 |
| 1976 | 1976-05-17 | 1976-10-02 |
| 1977 | 1977-04-08 | 1977-09-14 |
| 1978 | 1978-05-21 | 1978-09-27 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 15 | 98 | 1967 | 53 |
| 35 C (95 F): Days | 15 | 49 | 1967 | 22 |
| 40 C (104 F): Days | 12 | 16 | 1971 | 1 |
| 90 F (32.2 C): Days | 15 | 76 | 1967 | 34 |
| 100 F (37.8 C): Days | 15 | 26 | 1971 | 10 |
| 0 C (32 F): Ice days (max | 15 | 25 | 1972 | 16 |
| 0 C (32 F): Frost days (min | 15 | 92 | 1978 | 92 |
| -10 C (14 F): Days with min | 10 | 26 | 1972 | 7 |
| -20 C (-4 F): Days with min | 3 | 3 | 1964 | 1 |
| 20 C (68 F): Tropical nights (min | 15 | 27 | 1967 | 1 |
| 25 C (77 F): Days with min | 2 | 2 | 1965 | 1 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 13 | 10 | 1966 | 7 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 3 | 1 | 1965 | 1 |
| 10 cm (3.9 in): Days with 10 cm or more snowfall | 2 | 1 | 1963 | 1 |
Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1963.
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 2026-10-15 (15 October 2026). Threshold counts are computed by this site.
Data as of . Last revised (2025-12-31).