textproduct: San Juan

KEY MESSAGES

Issued at 225 PM AST Tue Jul 14 2026

* A Heat Advisory remains in effect through 5 PM AST this afternoon due to dangerous temperatures and heat indices across all coastal and urban areas of Puerto Rico and the U.S. Virgin Islands.

* A drier airmass along with high concentrations of Saharan dust will continue to spread across the region, promoting hazy skies, reduced visibilities, poor air quality and limited shower activity.

* A disturbance will reach the area by Thursday, increasing moisture and the potential for showers and thunderstorms. across the islands.

* Breezy conditions will maintain choppy seas for mariners and a moderate risk of rip currents across most local beaches.

Short Term(This evening through Thursday)

Issued at 225 PM AST Tue Jul 14 2026

Dry, hot conditions and hazy skies prevailed across the islands today, driven by a drier airmass and high concentrations of Saharan dust. High temperatures reached the upper 80s to low 90s, particularly along the coastal and urban areas of Puerto Rico and the U.S. Virgin Islands, where heat indices exceeded 105F. Meanwhile, highs in the mountains ranged from the low to mid-80s, with some valley areas in central Puerto Rico reaching the upper 80s. The Luis Munoz Marin International Airport in San Juan reported a maximum temperature of 81F by early afternoon. A Heat Advisory remains in effect until 5 PM AST across all urban and coastal areas of Puerto Rico and the U.S. Virgin Islands.

For the rest of the afternoon, dry conditions and high concentrations of Saharan dust will continue to dominate across the islands. Despite the dry airmass, a brief shower cannot be ruled out due to daytime heating and local effects, particularly over portions of western Puerto Rico.

A strengthening high-pressure over the central Atlantic and a mid- level ridge will continue to dominate over the next few days. This setup will promote a drying trend that is expected to persist through Wednesday, dropping precipitable water (PWAT) values below the climatological normal to 1.20-1.25 inches. While Saharan dust will gradually decrease on Wednesday, moderate to high concentrations will still persist across the region tomorrow. Sensitive groups, particularly those with respiratory illnesses or allergies, are advised to limit prolonged outdoor exposure and take necessary precautions due to reduced air quality.

By Thursday, an upper-level disturbance is expected to approach the northeastern Caribbean, resulting in a slight increase in instability and moisture. PWAT values will rise to seasonal levels of around 1.75 inches. This moisture, combined with favorable upper- level dynamics, daytime heating, and local effects, will trigger the development of showers and isolated thunderstorms across central and western Puerto Rico. During this period, Saharan dust concentrations will significantly diminish to trace levels, leading to improved air quality.

During the next few days, daytime highs are projected to increase into the 90s across coastal and urban areas during the early afternoon, while overnight temperatures will remain unseasonably warm as the Saharan dust layer traps heat and limits radiational cooling. Therefore, heat indices are highly likely to reach hazardous levels again on Wednesday. Residents and visitors are strongly encouraged to practice heat safety measures to mitigate the risk of heat-related illnesses.

Long Term(Friday through next Monday)

Issued at 225 PM AST Tue Jul 14 2026

During the long-term period, Friday will have the highest potential for rainfall as a weak upper-level low system interacts with a low-level perturbation moving across the local area. Moisture values are forecast to remain near seasonal normals, with sufficient mid-level moisture to support scattered showers, especially during the afternoon across the western sections of Puerto Rico and overnight into the morning hours over the U.S. Virgin Islands and eastern PR. While widespread flooding is not expected, locally heavy downpours could lead to ponding of water in low-lying and poor drainage areas. From Friday into the upcoming workweek, low concentrations of Saharan dust are expected to linger across the region. Although occasional hazy skies are likely, dust concentrations should remain low enough to have only minor impacts on visibility and rainfall coverage. Individuals with respiratory conditions may still experience some discomfort and should consider limiting prolonged outdoor exposure.

Saturday through Monday, a typical summertime pattern is expected. A slightly drier air mass arriving on Saturday may limit shower coverage, but daytime heating and local effects will continue to support isolated to scattered afternoon showers over the interior and western municipalities. By Sunday and Monday, cooler temperatures aloft associated with a weak upper-level trough will promote a modest increase in atmospheric instability, allowing afternoon convection to become somewhat more active. Even so, rainfall is expected to remain localized, with the primary hazards being brief periods of heavy rain, gusty winds near stronger thunderstorms, and isolated lightning strikes.

Warm to hot conditions will persist through the period as low- level temperatures remain above averages. Heat indices will likely exceed seasonal normals across urban and coastal areas. Residents and visitors are encouraged to stay hydrated, take frequent breaks in the shade or air conditioning, and avoid strenuous outdoor activities during the hottest part of the day.

AVIATION

(18Z TAFS) Issued at 225 PM AST Tue Jul 14 2026

VFR conds will prevail across all terminals through the fcst period. Limited VCSH/SHRA are more possible at TJBQ thru 14/23Z. High concentrations of Saharan dust will result in HZ over the islands, causing VIS reductions at all PR & USVI terminals. Gusty conds will prevail, with E- ESE winds at around 15-19 kt with gusts up to 30 kt 14/23Z, becoming light overnight at 5-10 kt through 15/13Z.

MARINE

Issued at 225 PM AST Tue Jul 14 2026

A surface high over the central Atlantic interacting with the PanamaColombia low will maintain a tight pressure gradient across the region, supporting moderate to locally fresh east-southeast winds and moderate to choppy seas for the next few days. A drier air mass, accompanied by moderate to high concentrations of Saharan dust, will continue to spread across the region through early Thursday, resulting in hazy skies and reduced visibility. A trade wind perturbation is expected to move through the area around Thursday, increasing the potential for passing showers and isolated afternoon thunderstorms.

BEACH FORECAST

Issued at 225 PM AST Tue Jul 14 2026

No changes were introduced to the beach forecast. The moderate risk of rip currents continues across northern and eastern-exposed beaches of Puerto Rico, including Culebra, and the U.S. Virgin Islands; low elsewhere. Although the risk remains moderate, beachgoers must exercise caution as life-threatening rip currents are possible along the surf zone. The moderate risk should continue for the next several days, though it may spread across most beaches of the islands by the weekend. In addition to rip currents, beachgoers must continue to stay updated on the weather conditions, as moderate to high concentrations of Saharan Dust will spread across the region, bringing hazy skies and deteriorating air quality; sensitive groups must follow medical recommendations. Shower and thunderstorm activity may increase on Thursday, bringing gusty winds and isolated lightning near coastal areas of the western side of Puerto Rico.

FIRE WEATHER

Issued at 225 PM AST Tue Jul 14 2026

A dry air mass and Saharan dust will continue to dominate the region today, keeping the fire danger risk elevated. This dry weather pattern will cause relative humidity (RH) levels to drop to critical threshold values between 40% and the low 50s during the early afternoon hours. In addition to the low humidity, winds will be favorable for rapid fire spread, blowing from the east- southeast at 10 to 15 mph with higher gusts.

Because of these critical conditions, a Fire Danger statement has been issued for most sections of the southern plains and across the northern coastal sectors of the island. Any fires that ignite in these areas could spread quickly and become difficult to control. Additional Red Flag Warning conditions are briefly possible; however, the limiting factor will be the south wind component that can trigger changes in the RH values.

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.