San Mateo County Natural Disasters and Weather Extremes
Hot California Rankings
The chance of earthquake damage in San Mateo County is much higher than California average and is much higher than the national average. The risk of tornado damage in San Mateo County is about the same as California average and is much lower than the national average.
Earthquake Index, #9
| San Mateo County | 32.44 |
| 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, #46
| San Mateo County | 0.0005 |
| 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, #20
| San Mateo County | 11.33 |
| 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 649 other weather extremes events within 50 miles of San Mateo County 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: | 1 | Cold: | 0 | Dense Fog: | 9 | Drought: | 0 |
| Dust Storm: | 0 | Flood: | 247 | Hail: | 30 | Heat: | 2 | Heavy Snow: | 2 |
| High Surf: | 2 | Hurricane: | 0 | Ice Storm: | 0 | Landslide: | 0 | Strong Wind: | 52 |
| Thunderstorm Winds: | 35 | Tropical Storm: | 0 | Wildfire: | 11 | Winter Storm: | 4 | Winter Weather: | 0 |
| Other: | 254 | ||||||||
Volcanos Nearby
A total of 1 volcano is found in or near San Mateo County.
| Distance (miles) | Name | Region | Latitude | Longitude | Elevation (foot) | Type | Status | Last Eruption |
| 109.5 | 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 166 historical earthquake events that had recorded magnitudes of 3.5 or above found in or near San Mateo County.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 36.0 | 1911-07-01 | 6.6 | N/A | 37.25 | -121.75 |
| 37.4 | 1984-04-24 | 6.2 | 8 | 37.32 | -121.7 |
| 32.6 | 1955-09-05 | 5.8 | N/A | 37.37 | -121.78 |
| 42.8 | 1980-01-24 | 5.8 | 8 | 37.83 | -121.79 |
| 31.4 | 1943-10-26 | 5.5 | N/A | 37.4 | -121.8 |
| 42.2 | 1955-10-24 | 5.4 | N/A | 37.97 | -122.05 |
| 43.0 | 1980-01-27 | 5.4 | 10 | 37.75 | -121.71 |
| 45.9 | 1964-11-16 | 5.3 | N/A | 37 | -121.72 |
| 42.5 | 1967-12-18 | 5.2 | N/A | 37.01 | -121.79 |
| 42.7 | 1980-01-24 | 5.1 | 3 | 37.8 | -121.76 |
| 43.4 | 1967-09-28 | 5 | N/A | 37.22 | -121.62 |
| 43.9 | 1967-09-28 | 5 | N/A | 37.22 | -121.61 |
| 46.0 | 1947-11-15 | 4.9 | N/A | 36.78 | -122.12 |
| 35.8 | 1981-01-15 | 4.8 | 9 | 37.38 | -121.72 |
| 38.8 | 1979-05-08 | 4.8 | 6 | 37.3 | -121.68 |
| 42.9 | 1980-01-24 | 4.8 | 1 | 37.84 | -121.8 |
| 47.9 | 1965-09-10 | 4.8 | N/A | 38 | -121.9 |
| 20.3 | 1958-12-11 | 4.7 | N/A | 37.68 | -122.53 |
| 28.1 | 1984-03-27 | 4.7 | 7 | 37.76 | -122.1 |
| 42.0 | 1967-09-07 | 4.7 | N/A | 37.04 | -121.77 |
| 43.7 | 1947-06-22 | 4.7 | N/A | 37 | -121.77 |
| 44.4 | 1973-10-03 | 4.7 | 8 | 37.28 | -121.58 |
| 44.9 | 1973-10-03 | 4.7 | 6 | 37.2 | -121.6 |
| 12.3 | 1963-05-22 | 4.6 | N/A | 37.3 | -122.2 |
| 43.2 | 1977-06-21 | 4.6 | 10 | 37.65 | -121.64 |
| 43.7 | 1977-06-21 | 4.6 | 10 | 37.65 | -121.63 |
| 44.2 | 1971-03-09 | 4.6 | 9 | 36.8 | -122.15 |
| 21.1 | 1932-11-03 | 4.5 | N/A | 37.16 | -122.16 |
| 24.8 | 1973-11-12 | 4.5 | 14 | 37.2 | -122.01 |
| 25.2 | 1973-11-12 | 4.5 | 14 | 37.2 | -122 |
| 25.2 | 1933-12-13 | 4.5 | N/A | 37.2 | -122 |
| 25.4 | 1952-10-13 | 4.5 | N/A | 37.75 | -122.18 |
| 25.5 | 1945-08-27 | 4.5 | N/A | 37.33 | -121.92 |
| 28.2 | 1937-03-08 | 4.5 | N/A | 37.8 | -122.2 |
| 35.2 | 1959-03-03 | 4.5 | N/A | 37 | -122 |
| 39.8 | 1963-09-21 | 4.5 | N/A | 37.27 | -121.67 |
| 43.7 | 1971-04-16 | 4.5 | 8 | 36.8 | -122.18 |
| 44.6 | 1982-08-18 | 4.5 | 11 | 37.02 | -121.73 |
| 47.6 | 1941-05-28 | 4.5 | N/A | 37.1 | -121.6 |
| 16.8 | 1957-03-22 | 4.4 | N/A | 37.65 | -122.45 |
| 17.0 | 1979-04-28 | 4.4 | 13 | 37.65 | -122.46 |
| 25.7 | 1981-03-03 | 4.4 | 10 | 37.56 | -121.94 |
| 35.6 | 1984-09-26 | 4.4 | 6 | 37.34 | -121.73 |
| 39.5 | 1984-05-03 | 4.4 | 10 | 37.29 | -121.67 |
| 17.1 | 1963-08-04 | 4.3 | N/A | 37.6 | -122.58 |
| 35.9 | 1970-06-12 | 4.3 | 9 | 37.8 | -121.93 |
| 43.7 | 1968-03-21 | 4.3 | N/A | 37.02 | -121.75 |
| 21.3 | 1957-03-23 | 4.2 | N/A | 37.7 | -122.52 |
| 28.8 | 1963-05-20 | 4.2 | N/A | 37.6 | -121.9 |
| 31.9 | 1958-10-31 | 4.2 | N/A | 37.5 | -121.8 |
| 36.1 | 1970-06-12 | 4.2 | 9 | 37.81 | -121.94 |
| 37.1 | 1978-07-02 | 4.2 | 10 | 36.9 | -122.18 |
| 43.0 | 1984-06-05 | 4.2 | 6 | 37.27 | -121.61 |
| 43.2 | 1980-01-25 | 4.2 | 6 | 37.83 | -121.78 |
| 43.3 | 1980-01-25 | 4.2 | 3 | 37.84 | -121.79 |
| 43.4 | 1980-01-25 | 4.2 | 5 | 37.85 | -121.8 |
| 44.6 | 1966-10-14 | 4.2 | N/A | 37 | -121.75 |
| 9.4 | 1957-10-31 | 4.1 | N/A | 37.35 | -122.22 |
| 34.9 | 1954-04-10 | 4.1 | N/A | 37.25 | -121.77 |
| 35.1 | 1981-04-25 | 4.1 | 11 | 37.1 | -121.87 |
| 35.2 | 1959-03-03 | 4.1 | N/A | 37 | -122 |
| 35.5 | 1943-04-29 | 4.1 | N/A | 37.56 | -121.75 |
| 35.9 | 1978-08-29 | 4.1 | 8 | 37.36 | -121.72 |
| 37.1 | 1959-03-24 | 4.1 | N/A | 37.27 | -121.72 |
| 37.4 | 1958-05-31 | 4.1 | N/A | 37.87 | -122 |
| 39.7 | 1943-04-26 | 4.1 | N/A | 37.63 | -121.7 |
| 40.2 | 1958-07-09 | 4.1 | N/A | 37.25 | -121.67 |
| 42.9 | 1980-01-27 | 4.1 | 8 | 37.84 | -121.8 |
| 43.7 | 1984-03-18 | 4.1 | 10 | 37.78 | -121.72 |
| 45.5 | 1962-03-17 | 4.1 | N/A | 37.87 | -121.77 |
| 47.2 | 1966-01-17 | 4.1 | N/A | 36.98 | -121.71 |
| 17.3 | 1957-03-23 | 4 | N/A | 37.65 | -122.48 |
| 19.6 | 1932-06-14 | 4 | N/A | 37.25 | -122.08 |
| 20.4 | 1941-09-18 | 4 | N/A | 37.4 | -122 |
| 33.8 | 1941-04-14 | 4 | N/A | 37.1 | -121.9 |
| 34.0 | 1976-08-20 | 4 | 7 | 37.79 | -121.97 |
| 35.1 | 1977-01-08 | 4 | 10 | 37.9 | -122.18 |
| 40.4 | 1980-08-24 | 4 | 5 | 37.57 | -121.66 |
| 44.9 | 1980-01-24 | 4 | 2 | 37.83 | -121.74 |
| 47.9 | 1968-12-11 | 4 | N/A | 37.16 | -121.56 |
| 49.3 | 1935-10-25 | 4 | N/A | 36.9 | -121.75 |
| 30.4 | 1982-08-24 | 3.9 | 6 | 37.46 | -121.82 |
| 34.7 | 1976-08-20 | 3.9 | 2 | 37.76 | -121.91 |
| 35.3 | 1951-07-24 | 3.9 | N/A | 37.92 | -122.27 |
| 40.3 | 1967-05-30 | 3.9 | N/A | 37.27 | -121.66 |
| 41.0 | 1961-08-18 | 3.9 | N/A | 37.93 | -122 |
| 16.2 | 1954-12-17 | 3.8 | N/A | 37.55 | -122.13 |
| 18.4 | 1957-03-22 | 3.8 | N/A | 37.67 | -122.47 |
| 18.6 | 1957-03-22 | 3.8 | N/A | 37.67 | -122.48 |
| 18.6 | 1957-03-23 | 3.8 | N/A | 37.67 | -122.48 |
| 19.6 | 1954-12-17 | 3.8 | N/A | 37.6 | -122.1 |
| 25.5 | 1983-06-04 | 3.8 | 6 | 37.72 | -122.11 |
| 31.5 | 1979-12-24 | 3.8 | 8 | 36.98 | -122.2 |
| 33.7 | 1978-05-11 | 3.8 | 3 | 37.37 | -121.76 |
| 34.8 | 1977-01-08 | 3.8 | 9 | 37.9 | -122.2 |
| 35.2 | 1970-05-26 | 3.8 | 4 | 37.8 | -121.95 |
| 36.0 | 1978-08-29 | 3.8 | 7 | 37.35 | -121.72 |
| 36.2 | 1984-12-28 | 3.8 | 6 | 37.33 | -121.72 |
| 37.0 | 1962-06-07 | 3.8 | N/A | 37.28 | -121.72 |
| 42.6 | 1961-11-17 | 3.8 | N/A | 37.97 | -122.03 |
| 43.7 | 1969-12-29 | 3.8 | N/A | 37.77 | -121.71 |
| 45.0 | 1982-08-28 | 3.8 | 12 | 37.85 | -121.76 |
| 46.3 | 1984-08-06 | 3.8 | 8 | 37 | -121.71 |
| 46.6 | 1947-09-20 | 3.8 | N/A | 36.87 | -121.87 |
| 47.4 | 1968-02-21 | 3.8 | N/A | 37.18 | -121.56 |
| 48.3 | 1948-01-14 | 3.8 | N/A | 37.87 | -121.7 |
| 2.9 | 1950-09-08 | 3.7 | N/A | 37.44 | -122.33 |
| 6.1 | 1981-12-12 | 3.7 | 9 | 37.38 | -122.27 |
| 17.4 | 1970-01-03 | 3.7 | 6 | 37.3 | -122.09 |
| 30.3 | 1948-07-20 | 3.7 | N/A | 37.45 | -121.82 |
| 32.1 | 1962-01-24 | 3.7 | N/A | 37.87 | -122.25 |
| 34.2 | 1978-05-11 | 3.7 | 4 | 37.38 | -121.75 |
| 34.7 | 1966-06-06 | 3.7 | N/A | 37.32 | -121.75 |
| 34.8 | 1965-06-28 | 3.7 | N/A | 37.52 | -121.75 |
| 37.5 | 1979-07-10 | 3.7 | 17 | 37.86 | -121.98 |
| 39.1 | 1947-09-25 | 3.7 | N/A | 36.87 | -122.18 |
| 39.6 | 1984-08-13 | 3.7 | 9 | 37.28 | -121.67 |
| 40.0 | 1959-06-11 | 3.7 | N/A | 37.33 | -121.65 |
| 41.5 | 1980-02-21 | 3.7 | 6 | 37.66 | -121.68 |
| 43.7 | 1982-10-19 | 3.7 | 11 | 37.03 | -121.74 |
| 46.5 | 1966-02-10 | 3.7 | N/A | 37.89 | -121.77 |
| 47.9 | 1984-04-26 | 3.7 | 5 | 37.14 | -121.57 |
| 49.3 | 1961-11-12 | 3.7 | N/A | 36.97 | -121.67 |
| 19.3 | 1957-03-22 | 3.6 | N/A | 37.68 | -122.48 |
| 28.7 | 1943-11-16 | 3.6 | N/A | 37.78 | -122.12 |
| 29.9 | 1961-02-16 | 3.6 | N/A | 37.83 | -122.22 |
| 31.4 | 1973-12-29 | 3.6 | 7 | 37.4 | -121.8 |
| 33.5 | 1983-05-19 | 3.6 | 6 | 37.33 | -121.77 |
| 34.1 | 1979-01-11 | 3.6 | 1 | 37.39 | -121.75 |
| 37.9 | 1983-10-23 | 3.6 | 7 | 37.33 | -121.69 |
| 40.3 | 1984-10-31 | 3.6 | 8 | 37.31 | -121.65 |
| 40.5 | 1984-08-16 | 3.6 | 6 | 37.26 | -121.66 |
| 40.8 | 1980-01-17 | 3.6 | 15 | 37.02 | -121.82 |
| 41.0 | 1984-08-24 | 3.6 | 6 | 37.26 | -121.65 |
| 42.7 | 1980-01-29 | 3.6 | 9 | 37.79 | -121.75 |
| 44.7 | 1948-01-31 | 3.6 | N/A | 37.97 | -121.95 |
| 47.4 | 1942-08-14 | 3.6 | N/A | 37.98 | -121.88 |
| 47.4 | 1984-04-26 | 3.6 | 5 | 37.14 | -121.58 |
| 8.4 | 1970-09-23 | 3.5 | 11 | 37.4 | -122.22 |
| 13.7 | 1977-07-27 | 3.5 | 11 | 37.31 | -122.16 |
| 15.2 | 1959-05-09 | 3.5 | N/A | 37.61 | -122.5 |
| 17.6 | 1948-12-10 | 3.5 | 16 | 37.2 | -122.2 |
| 20.1 | 1965-01-29 | 3.5 | N/A | 37.7 | -122.3 |
| 24.0 | 1980-12-31 | 3.5 | 10 | 37.7 | -122.12 |
| 27.7 | 1961-06-27 | 3.5 | N/A | 37.8 | -122.23 |
| 29.7 | 1954-02-08 | 3.5 | N/A | 37.8 | -122.13 |
| 30.4 | 1980-04-07 | 3.5 | 5 | 37.84 | -122.23 |
| 32.7 | 1979-08-13 | 3.5 | 9 | 37.86 | -122.17 |
| 33.0 | 1961-10-19 | 3.5 | N/A | 37.42 | -121.77 |
| 33.0 | 1976-07-07 | 3.5 | 10 | 37.44 | -121.77 |
| 33.6 | 1984-07-31 | 3.5 | 6 | 37.38 | -121.76 |
| 35.6 | 1970-05-29 | 3.5 | 7 | 37.8 | -121.94 |
| 35.7 | 1943-09-26 | 3.5 | N/A | 37.5 | -121.73 |
| 35.9 | 1962-04-07 | 3.5 | N/A | 37.37 | -121.72 |
| 36.1 | 1970-05-26 | 3.5 | 4 | 37.81 | -121.94 |
| 37.3 | 1977-12-12 | 3.5 | 7 | 37.33 | -121.7 |
| 37.7 | 1985-09-24 | 3.5 | 8 | 37.49 | -121.69 |
| 38.2 | 1984-05-17 | 3.5 | 6 | 37.3 | -121.69 |
| 39.8 | 1985-07-15 | 3.5 | 7 | 37.27 | -121.67 |
| 40.3 | 1984-07-29 | 3.5 | 7 | 37.27 | -121.66 |
| 42.5 | 1980-01-24 | 3.5 | 9 | 37.84 | -121.81 |
| 43.6 | 1979-02-21 | 3.5 | 12 | 37.83 | -121.77 |
| 44.2 | 1966-07-19 | 3.5 | N/A | 37.65 | -121.62 |
| 48.3 | 1960-06-28 | 3.5 | N/A | 36.92 | -121.75 |
| 48.6 | 1977-07-19 | 3.5 | 2 | 38.05 | -121.99 |
| 49.4 | 1983-06-05 | 3.5 | 13 | 38.01 | -121.87 |
Historical Tornado Events
A total of 2 historical tornado events that had recorded magnitude of 2 or above found in or near San Mateo County.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 16.3 | 1951-01-11 | 2 | 37°22'N / 122°07'W | 37°25'N / 122°02'W | 5.70 Miles | 33 Yards | 0 | 0 | 2.5M | 0 | Santa Clara |
| 18.8 | 1998-05-05 | 2 | 37°22'N / 122°02'W | 37°22'N / 122°02'W | 0.60 Mile | 100 Yards | 0 | 1 | 3.8M | 0 | Santa Clara |
| Brief Description: A Tornado touched down in the Chevy Chase residential area of Sunnyvale, CA near Hwy 85. The storm survey assessed the Damage to 15 home and a large chucrch as a mininimal F2.. One woman was injured when struck by flying debris. The storm was well documented on a video shot by a person from their backyard. The storm appears to be rotating anticyclonically from this video. This storm apparently developed from thunderstorms that developed in the lee of the Santa Cruz mountains over the W Santa Clara Valley. | |||||||||||
* 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.