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USGS Volcano Notice - DOI-USGS-HVO-2026-05-04T22:04:34+00:00

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HVO/USGS Volcanic Activity Notice

Volcano: Kilauea (VNUM #332010)

Current Volcano Alert Level: WATCH
Previous Volcano Alert Level: ADVISORY

Current Aviation Color Code: ORANGE
Previous Aviation Color Code: YELLOW


Issued: Monday, May 4, 2026, 1:50 PM HST
Source: Hawaiian Volcano Observatory
Notice Number: 2026/H204
Location: N 19 deg 25 min W 155 deg 17 min
Elevation: 4091 ft (1247 m)
Area: Hawaii

Volcanic Activity Summary:

Precursory low-level activity for episode 46 of the ongoing Halemaʻumaʻu eruption at the summit of Kīlauea began around 1:38 a.m. HST on May 4 with lava overflowing from the north vent. Accordingly, HVO is raising the Alert Level for Kīlauea from ADVISORY to WATCH and the Aviation Color Code from YELLOW to ORANGE. Alert level and aviation color code definitions: https://www.usgs.gov/programs/VHP/alert-level-system. This low-level precursory activity can continue for hours to days before the lava fountaining episode beings. The forecast for episode 46 of lava fountaining to start is between May 4-7. Another VAN will be published when lava fountaining episode 46 begins.

Most lava fountaining episodes since December 23, 2024, have continued for a day or less.



Remarks:

Hazard Analysis: 

Volcanic Gas: water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) are continuously released during an eruption. SO2 reacts in the atmosphere to create the visible haze known as vog (volcanic air pollution) downwind, which may cause respiratory and other problems. Further information on vog can be found at https://vog.ivhhn.org/

Tephra: small glassy volcanic fragments—volcanic ash, pumice, scoria, Pele’s hair and reticulite—are created by the lava fountains. A combination of fountaining dynamics and wind conditions determines where tephra fall may occur for any given eruption episode. Larger particles fall near the vents while light particles may be wafted greater distances. These particles may be remobilized during windy conditions following recent eruptive episodes. Residents and visitors should minimize exposure to these fragments, which can cause skin, eye, and respiratory irritation. More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/  

Lava flows: generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera. 

Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. Close to the vents, the tephra material on the crater rim is prone to cracking, slumping, and small landslides that sometimes expose hot and molten material within. This underscores the extremely hazardous nature of Kīlauea's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007.



Contacts:

askHVO@usgs.gov



Next Notice:

HVO continues to closely monitor Kīlauea and will issue additional notices as needed based on activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates  

More Information:



Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes

VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)

WMPA01 PHVO 042350   
VONA
DTG:                    20260504/2350Z
VOLCANO:                KILAUEA 332010
PSN:                    N1925 W15517
AREA:                   HAWAII
SOURCE ELEV:            4091FT AMSL
NOTICE NR:              2026/24
CURRENT COLOUR CODE:    ORANGE
PREVIOUS COLOUR CODE:   YELLOW
SVO:                    HAWAIIAN VOLCANO OBSERVATORY
ACT STS:                ERUPTION ONGOING
ONSET:                  20260504/2338Z
DUR:                    ONGOING EPISODIC
VA CLD HGT:             0FT AMSL
HGT SOURCE:             NO VA CLD PRODUCED
MOV:                    NO VA CLD PRODUCED
CTC:                    HVO DUTY SCIENTIST: 808-785-3144
RMK:                    LOW-LEVEL ERUPTION OF LAVA BEGAN AT THE SUMMIT OF KILAUEA AT 1:38 PM ON MAY 4, 2026.
                        LOW-LEVEL ACTIVITY CAN PRESIST FOR HOURS TO DAYS BEFORE THE LAVA FOUNTAIN EPISODE
                        BEGINS. LAVA FOUNTAIN EPISODE 46 IS FORECAST TO START BETWEEN MAY 4-7.
NXT NOTICE:             A NEW VONA WILL BE ISSUED IF COND CHANGE SIGNIFICANTLY OR IF THE COLOR CODE CHANGES
NNNN