QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Willows, CA

No earthquake was likely felt in Willows in the 24 hours to 6:38 am PST (14:38 UTC). The last one was M 4.0, 65 km (40 mi) W, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Willows

This page: a magnitude 2.1 earthquake was recorded 16 km (10 mi) east-southeast of Willows, CA, at 9:51 am PST on 28 February 2026 (17:51 UTC), 27 km deep.

USGS: 16 km ESE of Willows, CA

34 km (21 mi) SSW of Chico, CA · 113 km (70 mi) NNW of Sacramento, CA

9:51 am PST, Feb 28, 2026 · · 27 km deep · released about 41 lb of TNT

10 km30 km60 km120 km N Glenn County 36 kmButte County 40 kmColusa County 40 kmSutter County 57 kmYuba County 62 kmTehama County 73 kmLake County 77 kmYolo County 91 kmNevada County 108 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
9:51 am PST on 28 February 2026 ()
Where
16 km (10 mi) east-southeast of Willows, CA · earthquakes near Willows
Magnitude
M 2.1 (md)
Depth
27 km below the surface
Felt
no reports yet
Nearest
Glenn County, 36 km WNW
Nearest mapped fault
Great Valley thrust fault system, 24 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 249 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Willows, 16 km away, the estimate is intensity II (weak). 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.

Earthquakes near other towns within 30 km: Durham, Biggs, Hamilton City, Maxwell.

How big was it?

This earthquake released about 41 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 lb of TNT

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 4.2 on 2022-07-23 — about 1,700 times the energy of this one.

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

  1. 5.7 The 1975 Oroville, California Earthquake · 40 km E of this epicentre
  2. 5.2 4 km E of Palermo, California · 45 km E of this epicentre
  3. 5.1 5 km ENE of Palermo, California · 46 km E 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 39.4925, -122.0073. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Glenn County, CA 36 km (22 mi) WNW earthquakes near Glenn County
Butte County, CA 40 km (25 mi) ENE earthquakes near Butte County
Colusa County, CA 40 km (25 mi) SSW earthquakes near Colusa County
Sutter County, CA 57 km (35 mi) SSE earthquakes near Sutter County
Yuba County, CA 62 km (39 mi) ESE earthquakes near Yuba County
Tehama County, CA 73 km (45 mi) NNW earthquakes near Tehama County

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

Aftershocks so far

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

  1. 2.4 16 km ENE of Willows, CA
  2. 2.0 14 km S of Hamilton City, CA
  3. 2.0 5 km E of Williams, CA
  4. 2.7 5 km W of Hamilton City, CA
  5. 1.9 7 km ESE of Williams, CA
  6. 2.5 15 km S of Hamilton City, CA
  7. 2.2 4 km WSW of Hamilton City, CA
  8. 2.0 17 km E of Willows, CA
  9. 1.9 19 km E of Willows, CA
  10. 2.4 9 km S of Hamilton City, CA
  11. 1.9 5 km WSW of Concow, CA
  12. 3.1 9 km ENE of Colusa, CA
  13. 3.2 15 km E of Willows, 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.