Hundreds of Earthquakes Are Shaking Mount Rainier in Biggest Swarm in Years
The biggest earthquake swarm since 2009 is being observed at Mount Rainier, but according to scientists, the level of activity is no cause for concern.

Rumblings are happening deep below the surface at Mount Rainier, but the experts at the United States Geological Survey’s Cascades Volcano Observatory say this is normal activity and no cause for concern. So, those in and around the Pacific Northwest can breathe a sigh of relief that the volcano is not going to erupt today.
Current Earthquake Swarm
The current earthquake swarm started on July 8th at around 1:30 am local time. Hundreds of earthquakes have been observed since the beginning of this swarm, with rates up to several per minute. According to the United States Geological Survey (USGS), the largest magnitude so far has been a 1.7 that occurred at 4:52 PDT on July 8th. All of these earthquakes are happening anywhere from 1.2 to 3.7 miles below the surface.
On 7/8/25, the USGS & PNSN detected a swarm of earthquakes at Mount Rainier starting at 1:29AM PDT. Currently, there is no indication that the level of activity is cause for concern, alert level and color code for Mount Rainier remain at GREEN/NORMAL.https://t.co/RNK2skDTe9 pic.twitter.com/aZnyHheGsd
— PNSN (@PNSN1) July 8, 2025
When volcanic activity like this is observed, the USGS assigns a volcano alert level and aviation color code. Currently, the volcano alert level is Normal, and the aviation color code is Green.

According to the USGS, a Green/Normal rating means, “Non-erupting volcano is exhibiting typical background activity (including steaming, seismic events, thermal feature, or degassing).” This is the lowest level on the scale, which increases through Advisory, Watch and Warning, or Yellow, Orange and Red.
This is Normal For Mount Rainier
Mount Rainier is an active stratovolcano that is located about 60 miles south-southeast of Seattle. It is covered in glaciers and is the highest peak in the Cascade Range. Typically, around 9 earthquakes are located at the volcano per month, but swarms typically happen around one to two times per year.
An earthquake swarm is a cluster of earthquakes that occur in the same area in a relatively short time, but a swarm can last days or weeks. Unlike aftershocks, a swarm has no identifiable mainshock. Most of the time, swarms include mostly small, low-magnitude earthquakes.
There are no known safety concerns for visitors, staff, or adjacent communities related to the increased earthquake activity @MountRainierNPS summit. The alert level for Mount Rainier remains at GREEN/NORMAL. For updated information, visit USGS: https://t.co/G6qOyB9fah https://t.co/U2s4w7YyMK
— MountRainierNPS (@MountRainierNPS) July 8, 2025
According to the Cascades Volcano Observatory, “The Pacific Northwest Seismic Network is in the process of looking at each earthquake and identifying its location, depth and size, if possible. This process is called locating.”
The current swarm is expected to last for days, with the USGS continuing to monitor this event closely.
News Reference
Monitoring stations detect small magnitude earthquakes at Mount Rainier. USGS.