Earthquake · reviewed by a seismologist
M 3.5mw
Earthquake near Rialto, CA
No earthquake was likely felt in Rialto in the 24 hours to 9:13 am PST (17:13 UTC). The last one was M 2.1, 14 km (9 mi) SE, at 10:40 am PDT on 31 October 2026, estimated intensity II (weak) in town. Every earthquake near Rialto
This page: a magnitude 3.5 earthquake was recorded 6 km (4 mi) northwest of Rialto, CA, at 4:54 pm PDT on 5 August 2025 (23:54 UTC), 6.7 km deep. 1,125 people have reported feeling it to USGS.
USGS: 6 km NW of Rialto, CA
in Rialto, CA · 93 km (58 mi) E of Los Angeles, CA
- When
- 4:54 pm PDT on 5 August 2025 ()
- Where
- 6 km (4 mi) northwest of Rialto, CA · earthquakes near Rialto
- Magnitude
- M 3.5 (mw)
- Depth
- 6.7 km below the surface
- Felt
- 1,125 reports · strongest reported intensity IV
- Measured shaking
- intensity IV (ShakeMap)
- Nearest
- Orange County, 62 km SSW
- Nearest mapped fault
- San Jacinto fault, 2 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 310 days ago
Earthquake alerts for Rialto, CA
Get a notification in this browser when USGS records an earthquake near Rialto, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 62 km (39 mi) from the epicentre. In Rialto, 6 km away, the estimate is intensity III (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.
Likely felt in: Rialto 6 km, intensity III · Fontana 6 km, intensity III · Muscoy 7 km, intensity III · San Bernardino 12 km, intensity III · Colton 12 km, intensity III · Rubidoux 17 km, intensity III · Rancho Cucamonga 17 km, intensity III · Loma Linda 18 km, intensity III. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 2.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 68,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 3,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,100× the energy of this one
- This earthquake M 3.5 about 2.5 tons of TNT
- Around the size people start to feel M 3.0 this one released 5.2× 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 4.4 on 2018-08-29 — about 22 times the energy of this one.
Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:
- 6.2 3 km SE of San Bernardino, California · 16 km ESE of this epicentre
- 6.0 The 1910 Lake Elsinore, California Earthquake · 50 km S of this epicentre
- 5.6 7km ENE of Running Springs, CA · 36 km ENE of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 26 km W of this epicentre
- 5.4 5km S of Chino Hills, CA · 39 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 34.1455, -117.4142. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 62 km (39 mi) | SSW | earthquakes near Orange County |
| Los Angeles County, CA | 78 km (49 mi) | W | earthquakes near Los Angeles County |
| San Bernardino County, CA | 138 km (86 mi) | NE | earthquakes near San Bernardino County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
50 earthquakes have been recorded within 50 km since this one.
- 1.9 8 km ENE of North Tustin, CA
- 1.6 5 km W of Devore, CA
- 2.1 7 km WNW of Big Bear Lake, CA
- 1.9 2 km E of Calimesa, CA
- 1.9 6 km NW of Rialto, CA
- 2.1 6 km WNW of Lytle Creek, CA
- 2.1 3 km E of Moreno Valley, CA
- 2.0 7 km WSW of Calimesa, CA
- 2.5 0 km S of Loma Linda, CA
- 3.4 10 km N of La Verne, CA
- 1.6 11 km ENE of Trabuco Canyon, CA
- 1.5 5 km E of Calimesa, CA
- 2.5 6 km SSE of Mentone, CA
- 2.7 6 km N of Fontana, CA
- 1.6 7 km S of Redlands, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.