Published on Monday, June 29, 2026
By the A.M. Costa Rica staff

A massive cloud of Saharan dust, known as the Saharan Air Layer (SAL), is moving over Costa Rica, bringing hotter temperatures, drier weather and reduced air quality, according to the National Meteorological Institute (IMN).

The dense dust plume originated off the coast of West Africa and traveled more than 3,000 miles across the Atlantic Ocean before reaching the Caribbean.

According to the IMN, the dust began moving over Central America on Saturday, crossing from the Caribbean Sea to the Pacific Ocean.

Meteorologists expect it to keep temperatures elevated across Costa Rica for at least two more days.

The dust is contributing to drier conditions, hazy skies and above-average temperatures.

Highs are expected to reach about 80°F in the Greater Metropolitan Area, which includes parts of the provinces of San José, Alajuela, Cartago and Heredia.

Along the Pacific Coast, temperatures could climb as high as 93°F degrees.

"These fine particles can trap heat near the surface," meteorologists said, adding that temperatures are expected to remain above normal, particularly in coastal and urban areas.

The Ministry of Health warned that inhaling the dust may irritate the respiratory system and worsen allergies, asthma and other respiratory conditions.

According to the IMN, the Saharan dust is expected to begin dispersing by the middle of this week.

Costa Rica is also experiencing several days of sunny weather due to the annual phenomenon known as the "Veranillo de San Juan," or "Little Summer of St. John." The weather pattern, often compared to North America's "Dog Days of Summer," has brought sunshine to much of the country since it began last week.

Meteorologists expect the dry spell to weaken later this week as seasonal rainfall gradually returns.

Authorities have also issued an alert for parts of the Pacific coast because of the anticipated reduction in rainfall.   According to experts, weather conditions during the second half of the year are expected to be influenced by the El Niño-Southern Oscillation (ENSO).

Costa Rica has a tropical and subtropical climate with two primary seasons. The dry season, commonly referred to as summer, typically runs from December through May. The rainy season extends from June through November and generally coincides with the Atlantic hurricane season.

The National Meteorological Institute (IMN) is the government agency responsible for issuing weather forecasts, hazardous weather alerts and related services aimed at protecting the public and providing weather information to government agencies, businesses and residents.

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