Long-Term Research in Environmental Biology: Costa Rica

Climate at Maritza

Climatic diversity is a major contributor to the large diversity of ecosystems found in the ACG. They range from the cool moist cloud forests atop the mountains that separate the hot, dry (<1000 mm rain per year) plains near the Pacific ocean and the warm wet (>3000 mm of rain per year) lowland rain forests of the Caribbean.

Maritza climate data graph

Based on data from 1990-2006, Maritza has a strong seasonal climate — total rainfall averaged 2748 mm/yr (9 feet/yr), with 93% of total precipitation occurring during an ~8-month wet season (May-Dec; > 100 mm rain per month) and only 7% during a 4-month dry season (Jan-Apr). Sep (460 mm) and Oct (472 mm) are the wettest months and Mar (23 mm) and Apr (29 mm) are the driest months. Air temperature also exhibited a seasonal pattern, albeit not as dramatic as for rainfall. Maximum air temperature at Maritza averaged 27.2ºC (81ºF) while minimum air temperature averaged 20.4ºC (69ºF), a difference of only 6.8ºC (12ºF). Apr (max= 29.5ºC; min= 20.8ºC) and May (max= 28.7ºC; min= 21.1ºC) were the warmest months while Dec (max= 25.5ºC; min= 19.9ºC) and Jan (max =25.6ºC; min= 18.9ºC) were the coolest months.

Wind velocity has not been measured, but can be extremely high during the dry season months of January through March. These winds reflect an orographic interaction between the northeast trade winds and the Cordillera de Guanacaste.

Meterological data were collected manually at Maritza with daily records of maximum and minimum air temperature and total precipitation (24 h period beginning at 0700 h). Daily air temperature and precipitation (collected manually) span 1990 to present. Air temperature and precipitation at Santa Rosa are also available from the ACG (1979-present),  while the Stroud Water Research Center has collected precipitation data (1998-present) and air temperature (2006-present) at San Cristóbal between Volcán Cacao and Volcán Rincón de la Vieja.