textproduct: San Juan

KEY MESSAGES

Issued at 211 PM AST Mon Jun 22 2026

* Moderate concentrations of Saharan dust will filter across the islands once again today, resulting in hazy skies, reduced visibility, and degraded air quality, particularly for sensitive groups. Another pulse of SAL will arrive from Thursday onward.

* A weak tropical wave will move near the region between Wednesday and Thursday, bringing an additional chance for showers and thunderstorms.

* Life-threatening rip currents will remain possible at exposed beaches through much of the week due to persistent moderate to locally breezy winds. St Croix could have a high risk between Wednesday and Thursday due to these increasing winds.

Short Term(This evening through Wednesday)

Issued at 211 PM AST Mon Jun 22 2026

Hazy skies and warm temperatures persisted across the local islands throughout the morning hours. Satellite imagery showed patches of cloudiness moving across eastern Puerto Rico, resulting in brief periods of partly cloudy skies with little to no rainfall activity. In addition, the 22/12Z sounding from San Juan indicated a notably dry layer near the 700 mb level, supporting stable atmospheric conditions and limiting cloud development. Temperatures rose rapidly after sunrise under mostly sunny and hazy conditions associated with moderate concentrations of Saharan dust across the region. By 9 AM AST, the thermometer at Luis Munoz Marin International Airport had already reached 86F, increasing to 90F by 11 AM AST. Similar temperatures were reported by several unofficial stations along coastal areas. As temperatures continued to climb, heat indices also increased quickly, reaching between 106F and 109F across portions of north-central and northwestern Puerto Rico.

For the remainder of the day, warm temperatures and hazy skies will prevail as moderate concentrations of Saharan dust continue to affect the islands. In addition, very stable conditions prevail at the mid levels as a strong mid-level ridge remains in place across the northeastern Caribbean, promoting subsidence and limiting vertical cloud development. As a result, residents and visitors can expect generally tranquil weather conditions, with limited shower activity, reduced visibility at times, and above-normal temperatures. By Tuesday, the NASA Goddard Earth Observing System Model V5 guidance suggests a brief decrease in Saharan dust concentrations, resulting in somewhat less hazy conditions. By late Tuesday into Wednesday, weather conditions are expected to gradually change as moisture associated with the approaching of the moisture field from a tropical wave reaching the local area. Global model guidance continues to indicate that the deepest moisture associated with this feature will remain mostly over the Caribbean waters south of the islands. As has been common this season, another pulse of Saharan dust is expected to remain embedded within the periphery of the tropical wave. Consequently, conditions are forecast to remain warm, with a moderate chance of passing showers across eastern Puerto Rico and the U.S. Virgin Islands during the morning hours, followed by localized afternoon shower development across western Puerto Rico, although the lingering influence of the mid-level ridge should help limit the overall coverage and intensity of convection.

Long Term(Thursday through next Sunday)

Issued at 211 PM AST Mon Jun 22 2026

Mostly stable weather conditions are expected through the long-term period. While a tropical wave will pass south of the local islands on Thursday, the deepest moisture associated with the system is forecast to remain south of the area. A broad dry air mass will dominate the region, with precipitable water and relative humidity values remaining below normals. As a result, shower activity will be limited to brief trade-wind showers across windward and eastern areas during the overnight and morning hours, followed by isolated afternoon convection over portions of western Puerto Rico. Significant rainfall accumulations and flooding impacts are not anticipated.

Moderate to potentially high concentrations of Saharan dust are expected from Thursday through at least Saturday, promoting hazy skies and periods of reduced visibility. The driest day of the long- term period will be Friday. Individuals with respiratory sensitivities should consider limiting prolonged outdoor activities and following guidance from local health officials.

From Friday through Sunday, fair weather conditions will prevail across most of the region, with only isolated passing showers expected. Temperatures will remain near seasonal levels, while haze and localized reductions in visibility associated with Saharan dust remain the primary weather impacts through the end of the forecast period.

AVIATION

(18Z TAFS) Issued at 211 PM AST Mon Jun 22 2026

VFR conditions will persist across all TAF sites. HZ resulting in reduced VIS is forecast to persist until 23/15Z and even earlier for TIST & TISX. VCSH is expected until 22/21Z across TJBQ due to some SHRA along the western interior. Winds will persist from the E at 15 to 18 knots with gusty winds up to 28 knots at least until 22/23Z, decreasing and becoming more into 10 to 12 knots or even less, with land breeze variation, increasing again by 23/14Z. An improvement in VIS is forecast as HZ diminishes along the islands.

MARINE

Issued at 211 PM AST Mon Jun 22 2026

A broad surface high pressure system over the central Atlantic will maintain moderate to fresh easterly to east-southeasterly winds through the next several days, resulting in choppy seas across most of the local waters. Therefore, small craft should exercise caution. In addition, moderate to occasionally high concentrations of Saharan dust will persist into later tonight and Tuesday morning, producing hazy skies, reduced visibility, and poor air quality.

BEACH FORECAST

Issued at 211 PM AST Mon Jun 22 2026

A moderate risk of rip currents remains in effect for most local beaches, including northern and eastern Puerto Rico, Vieques, Culebra, and portions of the U.S. Virgin Islands, while a low risk persists for the south-central and western coasts of Puerto Rico and the northern U.S. Virgin Islands. Life-threatening rip currents remain possible.

SJU WATCHES/WARNINGS/ADVISORIES

PR...Heat Advisory until 5 PM AST this afternoon for PRZ001>005-007- 008-010>013.

VI...Heat Advisory until 5 PM AST this afternoon for VIZ001-002.

AM...None.