textproduct: San Juan

KEY MESSAGES

Updated at 1251 PM AST Tue Jun 2 2026

- High concentrations of Saharan dust will continue to result in hazy skies, reduced visibility, and poor air quality this afternoon, diminishing tonight. Another pulse of moderate concentrations is expected by Thursday.

- Warm to hot conditions are expected to continue over the next few days with limited to elevated heat risks persisting, particularly at lower elevations and urban areas of the islands.

- An increase in showers is expected on Wednesday and late in the weekend, increasing flood and lightning potential.

Short Term(This evening through Thursday)

Issued at 1251 PM AST Tue Jun 2 2026

Today, weather conditions remained dry and stable across Puerto Rico and the U.S. Virgin Islands under the influence of a hazy air mass. Similar to previous days, Saharan dust contributed to reduced visibility and hazy skies throughout the region, possibly affecting people with respiratory conditions. Maximum temperatures across coastal and urban areas generally reached the upper 80s to low 90s, while mountainous and rural locations remained in the upper 70s to low 80s. Easterly-southeasterly winds prevailed at 10 to 15 mph, with occasional higher gusts observed across coastal areas.

On Wednesday, a narrow patch of moisture embedded within the trade winds will move across the local islands. This feature will allow precipitable water values to briefly increase to near seasonal normals, while low-level moisture and cloud cover also increase. At the same time, Saharan dust concentrations are forecast to decrease too (low - moderate levels), resulting in somewhat improved visibility and air quality compared to previous days. Although the moisture increase will support a higher frequency of passing showers across windward areas and portions of the interior and western sections of Puerto Rico during the afternoon, the overall weather pattern will remain relatively stable, limiting the potential for widespread or significant rainfall accumulations. In addition, 925- mb temperatures are forecast to decrease slightly, promoting somewhat cooler daytime temperatures and lower heat indices compared to recent days.

By Thursday, the moisture patch will move away from the region, allowing drier air to filter back into the forecast area. Precipitable water values are expected to once again fall below normal levels for early June, while forecast soundings indicate a strengthening trade wind inversion and limited mid-level moisture. Saharan dust concentrations are expected to increase back to moderate levels, resulting in hazy skies across the islands. Consequently, weather conditions will return to a predominantly dry and stable pattern, with only isolated passing showers embedded within the trade wind flow and temperatures rebounding as 925-mb temperatures rise back above seasonal averages.

Long Term(Friday through next Monday)

Issued at 438 AM AST Tue Jun 2 2026

The latest model guidance continues to indicate a drier weather pattern during the long-term period across Puerto Rico and the U.S. Virgin Islands. A mid-level ridge will continue to promote dry and stable conditions aloft, while a strong Azores High drives breezy southeasterly winds through Monday.

Overall, the weather pattern remains characterized by below-normal precipitable water (PWAT) values for June, between 1.25 and 1.45 inches. However, patches of moisture will filter in from time to time, slightly increasing local moisture levels and bringing a few passing showers to portions of eastern Puerto Rico and the U.S. Virgin Islands. Enhanced by daytime heating and local effects, this moisture could support the development of afternoon showers across central to northwestern Puerto Rico. Conditions aloft will become slightly more favorable for thunderstorm activity as mid-level temperatures cool to seasonal values of -6 to -7 degrees Celsius, supported by an upper-level trough building to the west of the region.

Model guidance also suggests a tropical wave will approach by Sunday afternoon into Monday. As this wave arrives, it will bring additional moisture and enhance the potential for frequent showers across the region; however, uncertainty remains regarding potential flooding and rainfall impacts. Following the passage of the wave, another mass of drier air will filter into the area, dropping PWAT values back below normal. Therefore, the upcoming week will generally remain on the dry side. Additionally, a plume of moderate Saharan Air Layer is forecast to arrive and persist through the upcoming weekend, resulting in hazy skies, reduced visibility, and poor air quality. Sensitive groups, particularly individuals with respiratory conditions, should take necessary precautions to limit outdoor exposure and follow medical advice.

AVIATION

(18Z TAFS) Issued at 1251 PM AST Tue Jun 2 2026

VFR conditions will prevail. HZ and VSBY near 6SM due to Saharan dust over all TAF sites. Sfc winds will decrease to around 5 to 10 kt after 02/23Z. The ESE winds will gradually increase from 02/11Z as a moisture patch approaches the area.

MARINE

Issued at 1251 PM AST Tue Jun 2 2026

No changes were introduced to the marine forecast. From the latest scatterometer images, winds remain between 15 and 20 kt across regional waters due to a broad surface high pressure over the central Atlantic. Although seas near coastal areas should remain between 2 and 4 feet, offshore Atlantic waters should remain between 5 and 6 feet; small craft must exercise caution. This high will promote moderate to fresh east to southeast winds, resulting in choppy seas across the regional waters throughout the week. A small northerly swell is expected to arrive later tonight, likely to spread across local waters and passages, subsiding by Thursday. Concentrations of Saharan Dust will gradually diminish today, with shower activity increasing on Wednesday, but another pulse of moderate concentrations should filter into the region on Thursday.

BEACH FORECAST

Issued at 1251 PM AST Tue Jun 2 2026

The moderate risk of rip currents continues across northern, eastern, and southeastern beaches of Puerto Rico, including Vieques and Culebra, and the U.S. Virgin Islands, low elsewhere. Beachgoers must exercise caution, as life-threatening rip currents remain possible along beaches under moderate risk. As winds continue to strengthen, the moderate risk will likely persist and spread across the islands. Although a small northerly swell is expected to arrive later tonight and spread across local waters, the risk should remain moderate. Besides rip currents, beachgoers sensitive to Saharan Dust particles should follow medical recommendations, as moderate to high concentrations will persist throughout the week. A trade wind disturbance will bring showers on Wednesday, affecting mainly coastal areas of the U.S. Virgin Islands and eastern Puerto Rico during the morning, and isolated thunderstorms over western Puerto Rico in the afternoon.

FIRE WEATHER

Issued at 1251 PM AST Tue Jun 2 2026

The fire weather threat for today remains low, meaning somE isolated fire conditions remain possible, particularly over the southern coastal areas of PR.

SJU WATCHES/WARNINGS/ADVISORIES

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