Earthquake near Rialto, CA

No earthquake was likely felt in Rialto in the 24 hours to 3:12 am PST (11:12 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 4.4 earthquake was recorded 6 km (4 mi) northwest of Rialto, CA, at 9:32 am PDT on 31 July 2025 (16:32 UTC), 5.3 km deep. 8,298 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

9:32 am PDT, Jul 31, 2025 · 2025-07-31 16:32 UTC · 5.3 km deep · released about 55 tons of TNT

Every earthquake near Rialto Felt it? Tell USGS Check my area

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: 9:32 am PDT on 31 July 2025 (2025-07-31 16:32 UTC)
Where: 6 km (4 mi) northwest of Rialto, CA · earthquakes near Rialto
Magnitude: M 4.4 (mw)
Depth: 5.3 km below the surface
Felt: 8,298 reports · strongest reported intensity VI
Measured shaking: intensity IV (ShakeMap)
USGS impact alert: green
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 104 days ago · we first saw it 104 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 127 km (79 mi) from the epicentre. In Rialto, 6 km away, the estimate is intensity IV (light). 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 IV · Muscoy 6 km, intensity IV · Fontana 6 km, intensity IV · San Bernardino 12 km, intensity IV · Colton 12 km, intensity IV · Rubidoux 17 km, intensity IV · Rancho Cucamonga 17 km, intensity IV · Loma Linda 18 km, intensity IV. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 55 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.4 would have released about 32 times as much.

Northridge, California 1994 M 6.7 3,100× the energy of this one
Mineral, Virginia 2011 M 5.8 140× the energy of this one
Magna, Utah 2020 M 5.7 98× the energy of this one
This earthquake M 4.4 about 55 tons of TNT
Around the size people start to feel M 3.0 this one released 110× 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 1 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 Jul 23, 1923
6.0 The 1910 Lake Elsinore, California Earthquake · 50 km S of this epicentre May 15, 1910
5.6 7km ENE of Running Springs, CA · 36 km ENE of this epicentre Oct 16, 1999
5.5 The 1990 Upland, California Earthquake · 26 km W of this epicentre Feb 28, 1990
5.4 5km S of Chino Hills, CA · 39 km SW of this epicentre Jul 29, 2008

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

Map loads when it scrolls into view

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

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

2.0 7 km WSW of Calimesa, CA 23:01 UTC
2.5 0 km S of Loma Linda, CA 22:36 UTC
3.4 10 km N of La Verne, CA 00:11 UTC
1.6 11 km ENE of Trabuco Canyon, CA 13:10 UTC
1.5 5 km E of Calimesa, CA 12:02 UTC
2.5 6 km SSE of Mentone, CA 04:28 UTC
2.7 6 km N of Fontana, CA 23:42 UTC
1.6 7 km S of Redlands, CA 09:24 UTC
1.8 2 km NNE of Loma Linda, CA 04:16 UTC
2.5 1 km S of Mentone, CA 19:57 UTC
1.7 6 km S of Devore, CA 06:38 UTC
1.8 3 km SSE of Redlands, CA 15:11 UTC
2.8 6 km SSE of Mentone, CA 23:37 UTC
1.6 8 km SSE of Home Gardens, CA 18:05 UTC
1.9 5 km ENE of Rancho Cucamonga, CA 11:06 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 11:12 UTC. 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.