Saint Helena, CA Natural Disasters and Weather Extremes
The chance of earthquake damage in Saint Helena is much lower than California average and is much higher than the national average. The risk of tornado damage in Saint Helena is about the same as California average and is much lower than the national average.
Earthquake Index, #530
| Saint Helena, CA | 17.62 |
| California | 21.80 |
| U.S. | 1.81 |
The earthquake index value is calculated based on historical earthquake events data using USA.com algorithms. It is an indicator of the earthquake level in a region. A higher earthquake index value means a higher chance of an earthquake.
Volcano Index, #575
| Saint Helena, CA | 0.0055 |
| California | 0.0068 |
| U.S. | 0.0023 |
The volcano index value is calculated based on the currently known volcanoes using USA.com algorithms. It is an indicator of the possibility of a region being affected by a possible volcano eruption. A higher volcano index value means a higher chance of being affected.
Tornado Index, #981
| Saint Helena, CA | 9.84 |
| California | 18.56 |
| U.S. | 136.45 |
The tornado index value is calculated based on historical tornado events data using USA.com algorithms. It is an indicator of the tornado level in a region. A higher tornado index value means a higher chance of tornado events.
Other Weather Extremes Events
A total of 220 other weather extremes events within 50 miles of Saint Helena, CA were recorded from 1950 to 2010. The following is a break down of these events:
| Type | Count | Type | Count | Type | Count | Type | Count | Type | Count |
| Avalanche: | 0 | Blizzard: | 0 | Cold: | 0 | Dense Fog: | 6 | Drought: | 0 |
| Dust Storm: | 0 | Flood: | 93 | Hail: | 13 | Heat: | 2 | Heavy Snow: | 1 |
| High Surf: | 1 | Hurricane: | 0 | Ice Storm: | 0 | Landslide: | 0 | Strong Wind: | 20 |
| Thunderstorm Winds: | 11 | Tropical Storm: | 0 | Wildfire: | 2 | Winter Storm: | 1 | Winter Weather: | 0 |
| Other: | 70 | ||||||||
Volcanos Nearby
A total of 1 volcano is found in or near Saint Helena, CA.
| Distance (miles) | Name | Region | Latitude | Longitude | Elevation (foot) | Type | Status | Last Eruption |
| 36.1 | Clear Lake | US-California, United States | 38.97 | -122.77 | 1439 | Volcanic field | Holocene | Undated, but probable Holocene eruption |
Historical Earthquake Events
A total of 59 historical earthquake events that had recorded magnitudes of 3.5 or above found in or near Saint Helena, CA.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 45.2 | 1906-04-18 | 8.3 | 25 | 38 | -123 |
| 12.1 | 1969-10-02 | 5.7 | N/A | 38.45 | -122.68 |
| 12.2 | 1969-10-02 | 5.6 | N/A | 38.47 | -122.69 |
| 12.4 | 1969-10-02 | 5.6 | N/A | 38.46 | -122.69 |
| 43.3 | 1955-10-24 | 5.4 | N/A | 37.97 | -122.05 |
| 36.5 | 1955-05-07 | 5 | N/A | 38.93 | -122.87 |
| 3.3 | 1956-04-05 | 4.8 | N/A | 38.53 | -122.52 |
| 46.5 | 1965-09-10 | 4.8 | N/A | 38 | -121.9 |
| 20.9 | 1973-09-17 | 4.7 | 2 | 38.6 | -122.1 |
| 31.0 | 1963-12-30 | 4.7 | N/A | 38.8 | -122.9 |
| 13.7 | 1968-04-25 | 4.6 | N/A | 38.48 | -122.72 |
| 27.4 | 1933-05-16 | 4.5 | N/A | 38.63 | -122.95 |
| 31.5 | 1978-09-08 | 4.4 | 17 | 38.64 | -121.91 |
| 49.4 | 1954-11-10 | 4.4 | N/A | 39.07 | -123.03 |
| 11.5 | 1969-10-02 | 4.3 | N/A | 38.49 | -122.68 |
| 27.9 | 1982-05-29 | 4.3 | 3 | 38.8 | -122.82 |
| 27.5 | 1984-09-22 | 4.2 | 1 | 38.8 | -122.81 |
| 7.8 | 1959-12-16 | 4.1 | N/A | 38.58 | -122.36 |
| 27.5 | 1985-05-23 | 4.1 | 4 | 38.8 | -122.81 |
| 17.1 | 1977-09-22 | 4 | 5 | 38.6 | -122.76 |
| 19.5 | 1977-09-08 | 4 | 7 | 38.68 | -122.75 |
| 21.0 | 1969-05-08 | 4 | N/A | 38.7 | -122.17 |
| 22.5 | 1977-09-11 | 4 | 12 | 38.7 | -122.8 |
| 44.5 | 1977-01-08 | 4 | 10 | 37.9 | -122.18 |
| 13.4 | 1969-10-06 | 3.9 | N/A | 38.46 | -122.71 |
| 33.7 | 1980-12-12 | 3.9 | 4 | 38.96 | -122.69 |
| 41.7 | 1951-07-24 | 3.9 | N/A | 37.92 | -122.27 |
| 47.1 | 1961-08-18 | 3.9 | N/A | 37.93 | -122 |
| 47.6 | 1960-12-15 | 3.9 | N/A | 38.03 | -121.83 |
| 12.3 | 1974-03-21 | 3.8 | 2 | 38.6 | -122.66 |
| 14.9 | 1978-05-27 | 3.8 | 9 | 38.54 | -122.74 |
| 21.7 | 1977-09-11 | 3.8 | 9 | 38.68 | -122.8 |
| 26.3 | 1985-07-26 | 3.8 | 2 | 38.79 | -122.79 |
| 34.2 | 1977-06-04 | 3.8 | 26 | 38.2 | -121.97 |
| 43.9 | 1961-11-17 | 3.8 | N/A | 37.97 | -122.03 |
| 44.2 | 1977-01-08 | 3.8 | 9 | 37.9 | -122.2 |
| 46.8 | 1969-03-13 | 3.8 | N/A | 38.03 | -121.85 |
| 48.0 | 1985-04-18 | 3.8 | 14 | 39.11 | -122.03 |
| 49.6 | 1943-10-26 | 3.8 | N/A | 39.2 | -122.7 |
| 22.5 | 1966-12-23 | 3.7 | N/A | 38.7 | -122.8 |
| 28.7 | 1977-09-05 | 3.7 | 8 | 38.19 | -122.12 |
| 36.3 | 1979-06-17 | 3.7 | 16 | 38.1 | -122.04 |
| 43.2 | 1976-07-13 | 3.7 | 10 | 38.09 | -121.87 |
| 45.3 | 1962-01-24 | 3.7 | N/A | 37.87 | -122.25 |
| 23.3 | 1948-04-18 | 3.6 | N/A | 38.17 | -122.53 |
| 39.9 | 1970-08-31 | 3.6 | 8 | 38.1 | -121.94 |
| 46.3 | 1948-01-31 | 3.6 | N/A | 37.97 | -121.95 |
| 48.2 | 1942-08-14 | 3.6 | N/A | 37.98 | -121.88 |
| 48.4 | 1961-02-16 | 3.6 | N/A | 37.83 | -122.22 |
| 12.6 | 1969-10-02 | 3.5 | N/A | 38.5 | -122.7 |
| 15.5 | 1971-10-13 | 3.5 | 10 | 38.33 | -122.65 |
| 27.2 | 1985-07-26 | 3.5 | 2 | 38.8 | -122.8 |
| 31.0 | 1980-02-13 | 3.5 | 6 | 38.95 | -122.53 |
| 32.2 | 1985-03-06 | 3.5 | 2 | 38.94 | -122.68 |
| 36.7 | 1977-06-17 | 3.5 | 22 | 38.18 | -121.93 |
| 40.7 | 1977-07-19 | 3.5 | 2 | 38.05 | -121.99 |
| 47.1 | 1983-06-05 | 3.5 | 13 | 38.01 | -121.87 |
| 47.3 | 1979-08-13 | 3.5 | 9 | 37.86 | -122.17 |
| 47.6 | 1980-04-07 | 3.5 | 5 | 37.84 | -122.23 |
Historical Tornado Events
A total of 1 historical tornado event that had recorded magnitude of 2 or above found in or near Saint Helena, CA.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 24.3 | 1958-06-01 | 2 | 38°17'N / 122°59'W | 38°24'N / 122°45'W | 15.00 Miles | 50 Yards | 0 | 0 | 25K | 0 | Sonoma |
* The information on this page is based on the global volcano database, the U.S. earthquake database of 1638-1985, and the U.S. Tornado and Weather Extremes database of 1950-2010.