USVI Heat Advisories: What They Mean & What to Do

USVI Heat Advisories, Explained

A heat advisory in the U.S. Virgin Islands is an official National Weather Service alert that dangerous heat is expected. It is the signal to take precautions, and live WBGT is how you translate that territory-wide warning into a decision for your specific job site, field, or plan.

Last updated July 9, 2026 · Live data refreshes every 15 min

Official heat alerts and a live WBGT map do different, complementary jobs. The alert is an authoritative, forecast-based flag that the territory is heading into dangerous heat. WBGT is the real-time, location-specific number that tells you how to act on it. Use both.

Who issues them, and what they mean

Heat products for the USVI come from the National Weather Service forecast office in San Juan, which covers Puerto Rico and the Virgin Islands. Two levels matter most:

Heat Advisory, dangerous heat is expected; take precautions, limit strenuous outdoor activity, hydrate, and check on vulnerable people.
Excessive Heat Warning, more extreme, potentially life-threatening heat; avoid outdoor exertion, stay cool, and treat it seriously.

Locally, VITEMA (Virgin Islands Territorial Emergency Management Agency) and the VI Department of Health amplify these alerts and issue guidance. During any alert, their instructions come first.

What to do during an advisory

Reschedule strenuous outdoor activity to the coolest hours, or postpone it.
Hydrate ahead of thirst and take frequent shaded or cooled breaks.
Check on vulnerable people, infants, older adults, those with chronic illness, see the caregiver guide.
Watch for symptoms of heat exhaustion and heat stroke.
Use live WBGT to time and pace whatever you must do outdoors.

Advisory plus instrument. Think of the advisory as the territory-wide siren and the WBGT map as the dial on your specific location. When an advisory is in effect, the map helps you find the safest hour and spot to do what you need to do.

Always follow official National Weather Service advisories and VITEMA / VI Department of Health guidance during heat events. ClimaSafe is educational and does not issue or replace official alerts.

Sources

NOAA / NWS San Juan. Heat products for Puerto Rico and the U.S. Virgin Islands. weather.gov/sju
VITEMA, Virgin Islands Territorial Emergency Management Agency. vitema.vi.gov
U.S. NWS. WBGT. weather.gov/ict/WBGT

Frequently asked questions

Who issues heat advisories for the U.S. Virgin Islands?

The National Weather Service forecast office in San Juan issues heat products for Puerto Rico and the U.S. Virgin Islands. Territorial agencies, VITEMA for emergency management and the VI Department of Health for public-health guidance, amplify them and advise residents during heat events.

What is the difference between a Heat Advisory and an Excessive Heat Warning?

Both are issued by the National Weather Service based on forecast heat, generally using the heat index. An Advisory signals dangerous heat where caution is needed; a Warning signals more extreme, potentially life-threatening heat. A Warning is the more serious of the two, treat it accordingly.

Does ClimaSafe issue heat advisories?

No. ClimaSafe is an educational tool that shows live WBGT to help you make outdoor-activity decisions. It complements, but never replaces, official National Weather Service advisories and guidance from VITEMA and the VI Department of Health.