textproduct: San Juan

KEY MESSAGES

Updated at 321 AM AST Fri Jun 5 2026

* A drier weather pattern is forecast from today through Saturday, resulting in limited and localized shower activity, particularly during the afternoon hours. Although isolated showers are expected, flooding is not anticipated across northwestern Puerto Rico due to the limited coverage and intensity of the convection.

* A warming trend is forecast from today through Sunday as southeast winds persist across the region and abundant sunshine prevails during the daytime hours. Heat indices are expected to reach up to 108 degrees across urban and coastal areas of Puerto Rico.

* A pulse of Saharan dust is forecast to arrive late Saturday and persist through Monday. This dust intrusion will coincide with an increase in low-level moisture associated with an approaching tropical wave. As a result, hazy skies are expected across the region, while shower activity is forecast to increase on Sunday, particularly during the afternoon hours.

* There is a low to moderate risk of rip currents across the exposed beaches of Puerto Rico and the U.S. Virgin Islands.

Short Term(Today through Sunday)

Issued at 321 AM AST Fri Jun 5 2026

Variable weather conditions prevailed overnight across the local islands as a big patch of low-level moisture moved across the region, affecting mostly northern sections and the Atlantic waters. Periods of cloudiness and isolated passing showers affected portions of eastern Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands. Temperatures overnight remained around the seasonal normals, ranging from the upper 70s to lower 80s along coastal areas to cooler values across the higher elevations. East- southeasterly winds continued overnight under the influence of a broad surface high pressure system across the central Atlantic, with land breeze variations along the coastal areas.

A relatively dry and stable weather pattern is forecast from today through Saturday. At the surface, a broad high-pressure system over the central Atlantic will maintain east-to-east-southeasterly winds across the region. For today, the driest airmass with precipitable water values from 1.31 to 1.40 as shown by the derived satellite imagery. For Saturday, model guidance continues to suggest precipitable water values remaining below climatological normals while mid-level relative humidity values remain limited, supporting a more stable weather pattern across the forecast area. In addition, temperatures at 925 mb are forecast to remain near or above normal, promoting warm conditions each afternoon, particularly across northern and western Puerto Rico. Therefore, rainfall activity will remain limited through Saturday, with passing showers affecting eastern Puerto Rico and the U.S. Virgin Islands during the overnight and morning hours, followed by isolated afternoon convection across northwestern Puerto Rico. Heat indices will fluctuate between 100 and 111 degrees each afternoon across urban and coastal areas, with the highest values expected across northern and western Puerto Rico from 10 AM to 4 PM.

By Sunday, moisture associated with an approaching tropical wave is forecast to spread across the local islands. This will result in an increase in available moisture and shower activity across Puerto Rico and the U.S. Virgin Islands. At the same time, another pulse of Saharan dust is expected to move across the region, resulting in hazy skies and reduced visibility at times. Although the dust intrusion may limit the spatial coverage of rainfall, periods of showers are expected to become more frequent as the tropical wave moves across the northeastern Caribbean. The highest shower coverage is expected across eastern Puerto Rico and the U.S. Virgin Islands during the morning hours, followed by afternoon convection across interior and western Puerto Rico. Warm conditions will continue through the period, with elevated heat indices expected across urban and coastal areas. Overall, a more humid weather pattern is forecast by the end of the weekend as tropical moisture gradually increases across the forecast area.

Long Term(Monday through Friday)

Issued at 321 AM AST Fri Jun 5 2026

A fairly persistent trade wind pattern is forecast to continue through the long-term period, with Atlantic high pressure maintaining an easterly to east-southeasterly low-level flow across the northeastern Caribbean. Winds will remain breezy at times on Monday, especially near coastal areas, but the pressure gradient should relax through midweek, allowing winds to become lighter. A modest increase in trade wind speeds is possible again late in the week.

Lingering moisture from the wetter pattern expected on Sunday will keep Monday somewhat active. However, a moderate concentration of Saharan dust is expected Monday into Tuesday, which may limit shower intensity at times by promoting a drier and more stable air mass aloft. This will also lead to hazy skies and reduced visibility, especially across coastal waters and exposed areas. Even so, low- level moisture should remain sufficient to support passing showers across eastern Puerto Rico and the U.S. Virgin Islands during the overnight and morning hours, followed by isolated to scattered afternoon showers across western Puerto Rico.

A relative minimum in moisture is expected from Tuesday into Wednesday. During this time, precipitable water values trend closer to climatology, and mid-level moisture remains limited. This should result in a more typical and somewhat quieter trade wind pattern, with brief morning showers across windward areas and only localized afternoon convection across western Puerto Rico. Overall rainfall amounts should remain light to moderate and mostly confined to areas where sea breeze and local effects enhance shower development.

By late Wednesday and continuing into Friday, moisture is forecast to gradually increase again as shallow patches embedded in the trades move across the region. The available moisture, along with local and diurnal forcing, should lead to a gradual uptick in shower coverage. Passing showers will be more likely across windward sections during the nighttime and morning hours, followed by scattered afternoon showers and a few isolated thunderstorms across western and interior Puerto Rico. The wetter trend should persist into Friday, though the overall pattern still favors intermittent activity rather than a widespread rainfall event.

Temperatures near 925 mb remain close to climatology, suggesting seasonable daytime highs; however, heat indices may still reach elevated levels across coastal and urban locations during breaks in cloud cover and rainfall.

AVIATION

(06Z TAFS) Issued at 321 AM AST Fri Jun 5 2026

VFR conditions will remain in place across all TAF sites during the period. Winds will remain up to 12 knots at least until 05/15Z, increasing up to 15 to 18 knots from the E-SE with gusty winds and sea breeze variation. VCSH to -SHRA are expected across TJBQ at 05/19Z, reducing VIS and lowering the ceiling briefly. The rest of the TAF sites might experience some VCSH during the period. Winds will remain up to 15 knots during the period, diminishing at 05/23Z again.

MARINE

Issued at 321 AM AST Fri Jun 5 2026

Broad surface high pressure over the eastern Atlantic will promote moderate to locally fresh east to southeast winds through the weekend into early next week. As a result, choppy seas are expected to continue across the regional waters. Additionally, small pulses of a northerly swell are forecast to be present through the end of the week. Seas should remain between 3 and 4 feet near coastal areas and between 5 and 6 feet, occasionally higher, across the offshore Atlantic waters, where small craft operators should exercise caution. Low to moderate concentrations of Saharan dust will slightly reduce visibility through Saturday. Dust concentrations are then expected to increase further on Sunday

BEACH FORECAST

Issued at 321 AM AST Fri Jun 5 2026

Breezy winds, combined with a few pulses of a small northerly swell, will maintain a moderate rip current risk through the weekend along the north, east, and southeast beaches of Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands. By Monday, winds will increase slightly further, and the moderate risk will expand to include beaches along southern Puerto Rico as well. The risk along the west and southwest coasts of Puerto Rico will remain mainly low for most of the period. However, remember that even when the risk is low, life-threatening rip currents can occur near groins, jetties, reefs, and piers. By Tuesday, the risk is expected to decrease along most beaches. Stay tuned to the latest forecasts. For more information, visit weather.gov/beach/sju.

FIRE WEATHER

Issued at 321 AM AST Fri Jun 5 2026

A reduction of cloudiness and moisture is expected for today across the area as the patch of cloudiness moves north out of the region. Precipitable water values will drop into the 1.3 in and RH values will remain in the upper 50s to the lowers 60s. Winds will remain up to 15 knots, and even more breezy along coastal areas due to sea breeze variation. Given the expected conditions the fire danger threat will remain low to moderate fire danger risk. Please stay tune for further updates.

SJU WATCHES/WARNINGS/ADVISORIES

PR...None. VI...None. AM...None.