The Turrialba volcano began erupting Thursday just before 7 a.m., and it continued through much of the day.
Aviation officials close the Tobias Bolañoa airport in Pavas three times to clean ash from the runway.
The volcano still was erupting periodically as night fell, according to the remote cameras on the lip of the crater.
The initial eruptions sent a column 1,000 meters into the air, more than 3,000 feet. The vapor was dark indicating that it contained a lot of ash. Some eruptions are mainly water vapor.
Clouds kept volcano experts from watching the entire series of eruptions Thursday. By 3:51 p.m., the Observatorio Vulcanológico y Sismológico said that the emissions were mainly water vapor. Still, the Pavas airport closed down for a third time from 5 to 6 p.m. to brush away the ash.
The wind direction changed several times during the day, according to the Instituto Meteorológico Nacional, and there were reports of ash falls in San José, Coronado, La Uruca, Tibás, Rancho Redondo, Guadalupe, Moravia, Ipís, Sabanilla, La Guácima de Alajuela, San Rafael de Alajuela, Heredia, Turrubares, Orotina and Esparza, said the Observatorio Vulcanológico.
The Red Sismológica Nacional said that small tremors continued under the mountain and noted that the volcano had been relatively quiet for nine days.