QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6mw

Earthquake near Angwin, CA

No earthquake was likely felt in Angwin in the 24 hours to 5:20 am PST (13:20 UTC). The last one was M 1.6, in Angwin, at 11:57 pm PDT on 10 October 2026, estimated intensity II (weak) in town. Every earthquake near Angwin

This page: a magnitude 3.6 earthquake was recorded in Angwin, CA, at 2:30 pm PDT on 7 July 2026 (21:30 UTC), 8.7 km deep. 207 people have reported feeling it to USGS.

USGS: 0 km W of Angwin, CA

89 km (55 mi) N of San Francisco, CA · 26 km (16 mi) ENE of Santa Rosa, CA

2:30 pm PDT, Jul 7, 2026 · · 8.7 km deep · released about 4.1 tons of TNT

10 km30 km60 km120 km N Napa County 14 kmSonoma County 41 kmYolo County 49 kmSolano County 57 kmMarin County 64 kmLake County 64 kmColusa County 70 kmSutter County 83 kmContra Costa County 85 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
2:30 pm PDT on 7 July 2026 ()
Where
in Angwin, CA · earthquakes near Angwin
Magnitude
M 3.6 (mw)
Depth
8.7 km below the surface
Felt
207 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Napa County, 14 km SE
Nearest mapped fault
West Napa fault, 9 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 54 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 70 km (43 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Angwin in town, intensity III · Calistoga 11 km, intensity III · Kenwood 20 km, intensity III · Santa Rosa 27 km, intensity III · Agua Caliente 28 km, intensity III · Windsor 32 km, intensity II · Rohnert Park 34 km, intensity II · Napa 34 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 4.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 42,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,300× the energy of this one
  4. This earthquake M 3.6 about 4.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 8.5× more

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km since 2016 was M 5.0 on 2016-12-14 — about 120 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 42 km SSE of this epicentre
  2. 5.3 3 km E of Bloomfield, California · 42 km SW of this epicentre
  3. 5.3 Northern California · 43 km SW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 38.5762, -122.4555. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 14 km (8 mi) SE earthquakes near Napa County
Sonoma County, CA 41 km (26 mi) W earthquakes near Sonoma County
Yolo County, CA 49 km (31 mi) ENE earthquakes near Yolo County
Solano County, CA 57 km (35 mi) SE earthquakes near Solano County
Marin County, CA 64 km (40 mi) SSW earthquakes near Marin County
Lake County, CA 64 km (40 mi) NNW earthquakes near Lake County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

60 earthquakes have been recorded within 50 km since this one.

  1. 2.4 6 km NW of The Geysers, CA
  2. 1.9 9 km NW of The Geysers, CA
  3. 2.6 3 km ENE of The Geysers, CA
  4. 2.7 3 km ENE of The Geysers, CA
  5. 2.4 3 km NW of The Geysers, CA
  6. 1.5 10 km WNW of Cobb, CA
  7. 1.6 10 km WNW of Cobb, CA
  8. 1.5 8 km WSW of The Geysers, CA
  9. 1.8 9 km WNW of The Geysers, CA
  10. 2.4 4 km E of Saint Helena, CA
  11. 1.6 7 km W of Cobb, CA
  12. 1.8 7 km WNW of Cobb, CA
  13. 1.8 4 km W of Cobb, CA
  14. 1.7 2 km NW of The Geysers, CA
  15. 1.8 7 km NW of The Geysers, CA

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.