Mayon Alert Level 2: What the Latest PHIVOLCS Data Says

Mayon Alert Level 2 is unchanged as of the PHIVOLCS bulletin dated 11 September 2026, which describes the volcano’s condition as decreased unrest. Sulfur dioxide output was measured at 5,363 tonnes on 10 September, down from the 7,115 tonnes recorded on 31 August that drew a round of warnings, and still above the 3,844 tonne daily average since the alert was raised on 5 August.

Both readings are real. Neither one changes the alert level, and that’s the part worth holding onto.

What does the current PHIVOLCS bulletin actually say?

The current PHIVOLCS Mayon bulletin says the volcano is on Alert Level 2 in a state of decreased unrest, with 5,363 tonnes of sulfur dioxide measured on 10 September and 7 volcanic earthquakes in the past 24 hours. Six monitored parameters as published for 11 September 2026:

Parameter	Reading
Alert Level	2, described as decreased unrest
Seismicity	7 volcanic earthquakes
Sulfur dioxide flux	5,363 tonnes per day, measured 10 September
Crater glow	Fair, visible to the naked eye
Plume	Obscured
Ground deformation	Inflation of the edifice, with short-term deflation on the northeastern sector

The standing prohibitions haven’t moved either. Entry into the six-kilometre Permanent Danger Zone is not allowed, and neither is flying aircraft close to the volcano.

Why did one reading get reported as a surge?

One reading got reported as a surge because 7,115 tonnes on 31 August was close to double the running average, and it arrived alongside twelve low-frequency earthquakes and swelling detected on the northern and eastern flanks. On its own that is a genuine signal and PHIVOLCS flagged it as one.

What the coverage couldn’t include, because it hadn’t happened yet, is the next ten days. Put the three figures in order and the shape changes:

Date	Sulfur dioxide, tonnes per day
Average since 5 August	3,844
31 August	7,115
10 September	5,363

A single day is a data point. Three are the beginning of a line. The number came down, it hasn’t come down to baseline, and the agency’s own summary word moved from a caution about possible renewed eruptive activity to decreased unrest.

What does Mayon Alert Level 2 actually mean?

Mayon Alert Level 2 means moderate unrest: the volcano is showing activity above its normal background, driven by shallow magma or hydrothermal processes, and the standing response is a closed six-kilometre radius rather than an evacuation order. It sits in the middle of a scale that runs from 0 to 5.

The level is a decision, not a measurement. PHIVOLCS raises or lowers it by reading several parameters together, which is why a single figure moving in either direction does not move the level on its own. That is exactly what the past five weeks have shown.

Level	What it signals
0	No alert, normal background
1	Low-level unrest
2	Moderate unrest, where Mayon sits now
3	Increasing tendency toward a hazardous eruption
4	Hazardous eruption possible within days
5	Hazardous eruption in progress

Is decreased unrest the same as safe?

Decreased unrest is not the same as safe, and the alert level is the proof. Mayon Alert Level 2 has held since 5 August without interruption, through both the spike and the decline.

The hazards PHIVOLCS lists at Mayon Alert Level 2 have not been withdrawn:

• sudden steam-driven or phreatic eruptions, which come with little or no warning
• rockfalls, landslides and avalanches
• lahars during heavy and prolonged rainfall

That third one deserves attention in September. Lahar risk is a rainfall problem sitting on top of a volcano problem, and it doesn’t wait for the alert level to rise.

How does this compare with the 2023 eruption sequence?

Mayon reached Alert Level 3 in June 2023 and stayed there for months, which is the last sequence most residents will have in mind. The difference between that and now is the direction of travel and the response it triggers.

At Alert Level 3 the danger zone widens beyond six kilometres and evacuation of permanent danger zone communities becomes the operating assumption rather than a contingency. At Mayon Alert Level 2 the six-kilometre radius is the whole restriction, and nothing in the 11 September bulletin asks for more than that.

Worth saying plainly: nothing in the current readings indicates a move to Level 3. Nothing in them rules it out either, and PHIVOLCS does not forecast level changes in a 24-hour bulletin.

What the readings do not establish

Four things this data does not settle, and each one matters before anyone treats the decline as an all-clear:

1. Whether the downward move continues, or whether 10 September is one point on a line that turns again.
2. What the inflation of the edifice means when it is paired with short-term deflation on one sector, since the bulletin reports the observation without interpreting it.
3. Whether the twelve earthquakes reported in early September and the seven reported now represent a trend or ordinary variation.
4. Whether any evacuation or relocation from the earlier unrest is still in place, which is an LGU record rather than a PHIVOLCS one.

The fourth is the one a resident can actually act on, and it’s the one no volcano bulletin will answer. We have tracked what the public record showed about earlier Mayon evacuees before, and the same gap applied then.

What should residents watch next?

Residents should watch three things on Mayon: the alert level itself, the daily sulfur dioxide figure measured against the 3,844 tonne average for this episode, and rainfall, separately from the volcano. Read the PHIVOLCS bulletin rather than the headline that summarises it, because the bulletin publishes every parameter and a headline publishes one.

• The alert level itself. Mayon Alert Level 2 is a single number, it changes rarely, and every recommendation follows from it.
• The sulfur dioxide figure against 3,844. That average is the reference point for this episode. A reading under it is meaningful, a reading over it is ordinary for now.
• Rainfall, separately. Lahar hazard is listed at the current alert level and is driven by weather, not by the volcano waking up.

PHIVOLCS publishes a 24-hour summary for Mayon every day, in English and Filipino, in the same place. It costs a minute to read the actual parameters, and that’s the difference between knowing the alert level and guessing at it.

The part worth holding onto

Mayon Alert Level 2 didn’t change. Between 31 August and 11 September the sulfur figure roughly halved the gap back toward its average, the earthquake count fell, PHIVOLCS changed its own summary word, and Mayon Alert Level 2 stayed exactly where it has been since 5 August.

A number moving isn’t the same as a status changing. On a volcano that distinction is the whole point of having alert levels, and the six-kilometre zone stays closed either way.

Source PHIVOLCS, reported 11 September 2026. Written from the original report.