Washington County Natural Disasters and Weather Extremes
The chance of earthquake damage in Washington County is higher than Oregon average and is lower than the national average. The risk of tornado damage in Washington County is higher than Oregon average and is much lower than the national average.
Earthquake Index, #2
| Washington County | 1.60 |
| Oregon | 0.62 |
| 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, #17
| Washington County | 0.0168 |
| Oregon | 0.0291 |
| 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, #2
| Washington County | 18.83 |
| Oregon | 8.38 |
| 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 574 other weather extremes events within 50 miles of Washington 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: | 0 | Cold: | 0 | Dense Fog: | 0 | Drought: | 0 |
| Dust Storm: | 0 | Flood: | 140 | Hail: | 53 | Heat: | 0 | Heavy Snow: | 6 |
| High Surf: | 0 | Hurricane: | 0 | Ice Storm: | 0 | Landslide: | 0 | Strong Wind: | 28 |
| Thunderstorm Winds: | 59 | Tropical Storm: | 0 | Wildfire: | 8 | Winter Storm: | 0 | Winter Weather: | 0 |
| Other: | 280 | ||||||||
Volcanos Nearby
A total of 11 volcanoes are found in or near Washington County.
| Distance (miles) | Name | Region | Latitude | Longitude | Elevation (foot) | Type | Status | Last Eruption |
| 54.0 | West Crater | US-Washington, United States | 45.88 | -122.08 | 1329 | Volcanic field | Radiocarbon | Last known eruption B.C. (Holocene) |
| 62.8 | St. Helens | US-Washington, United States | 46.2 | -122.18 | 2549 | Stratovolcano | Historical | Last known eruption 1964 or later |
| 66.8 | Indian Heaven | US-Washington, United States | 45.93 | -121.82 | 1513 | Shield volcano | Radiocarbon | Last known eruption B.C. (Holocene) |
| 69.1 | Hood | US-Oregon, United States | 45.374 | -121.694 | 3426 | Stratovolcano | Historical | Last known eruption 1800-1899 |
| 86.8 | Jefferson | US-Oregon, United States | 44.692 | -121.8 | 3199 | Stratovolcano | Varve Count | Last known eruption A.D. 1-1499 |
| 89.4 | Adams | US-Washington, United States | 46.206 | -121.49 | 3742 | Stratovolcano | Tephrochronology | Last known eruption A.D. 1-1499 |
| 99.1 | Sand Mountain Field | US-Oregon, United States | 44.38 | -121.93 | 1664 | Cinder cone | Radiocarbon | Last known eruption B.C. (Holocene) |
| 101.6 | Blue Lake Crater | US-Oregon, United States | 44.42 | -121.77 | 1230 | Maar | Radiocarbon | Last known eruption B.C. (Holocene) |
| 104.4 | Washington | US-Oregon, United States | 44.332 | -121.837 | 2376 | Shield volcano | Radiocarbon | Last known eruption A.D. 1-1499 |
| 107.0 | Belknap | US-Oregon, United States | 44.285 | -121.841 | 2095 | Shield volcano | Radiocarbon | Last known eruption A.D. 1-1499 |
| 115.5 | North Sister Field | US-Oregon, United States | 44.17 | -121.77 | 3074 | Complex volcano | Radiocarbon | Last known eruption A.D. 1-1499 |
Historical Earthquake Events
A total of 5 historical earthquake events that had recorded magnitudes of 3.5 or above found in or near Washington County.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 17.6 | 1964-10-01 | 5.3 | N/A | 45.7 | -122.8 |
| 21.3 | 1962-11-06 | 4.8 | N/A | 45.63 | -122.67 |
| 49.2 | 1963-03-07 | 4.6 | N/A | 44.9 | -123.5 |
| 17.8 | 1963-12-27 | 4.5 | N/A | 45.7 | -123.4 |
| 45.4 | 1984-06-04 | 3.7 | 53 | 46.21 | -123.06 |
Historical Tornado Events
A total of 2 historical tornado events that had recorded magnitude of 2 or above found in or near Washington County.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 22.7 | 1972-04-05 | 3 | 45°36'N / 122°38'W | 45°36'N / 122°38'W | 0 | 0 | 250K | 0 | Multnomah | ||
| 27.2 | 1972-04-05 | 3 | 45°36'N / 122°38'W | 45°38'N / 122°27'W | 8.70 Miles | 440 Yards | 6 | 300 | 25.0M | 0 | Clark |
* 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.