Climate

At the geographical coordinates 17° 30 and 19° 56 latitude north and 68° 19 and 72° 31 longitude west, the Dominican Republic is considered to be located in the tropical region of the world. It has an uneven relief, as approximately 50% of its territory is occupied by five sierras and 3 large mountain ranges, in which the highest altitudes of the Antilles can be found (Pico Duarte, 3,187 msnm). The remaining surface of the national territory is composed of four large valleys; the largest is the Valle del Cibao. All of these systems run northwest to southeast, influencing the direction of the trade winds, which in turn affects the distribution of rain, giving the country diverse and contrasting microclimates.

In the Dominican Republic, nine ecological zones and seven transition formations have been identified. Wet subtropical forest is the climate that covers the most area and is found dispersed throughout the national territory. The country is also divided into 20 geomorphological regions and eight subregions.

Did you know? The Dominican Republic, due to its geographical position, boasts a tropical climate influenced by various geographical factors, like orography and the influence of the trade winds, in addition to the atmospheric phenomena that affect it year-round.

Temperature

The variation in temperature behavior in the Dominican Republic is intimately associated with two basic factors: geographical location and the mountainous systems that exist throughout the country. The Dominican Republic has a median annual temperature of 25° C (77° F), which is defined as a hot tropical climate. The highest temperatures, around 34° C (93° F), are usually reached in the months from June to August, while the lowest, 19° C (66° F), arrive in the months between December and February. 

Did you know? Two low temperature zones coincide with the highest section of the Cordillera Central and a third low temperature center stretches from the Cordillera Septentrional to the Atlantic coast in the Río Yásica basin.

Precipitations

In the Dominican Republic, there are three rainy seasons: the Temporada Frontal (November – April), the Temporada Convectiva (May – July) and the Temporada Ciclónica (August – October).

High precipitation zones are highly influenced by trade winds carrying humidity over the Atlantic, which arrive to the country from the Northeast, producing the so-called lluvias orográficas (orographic rains). This phenomenon occurs first in the Cordillera Septentrional and the Sierra de Yamasá and later in the Cordillera Central. Annual rainfall in these areas fluctuates between 1,800 and 2,500 mm, with exceptions in the karstic zone of Los Haitises, where more than 3,000 mm per year has been recorded.

The same relationship, inversed, explains rainfall in the areas of least precipitation, which are fragile, prone to drought and desertification.  Such is the case in the Northwest regions, with a precipitation between 600 and 900 mm and the Southwest region, whose precipitation oscillates between 400 and 700 mm.

To access daily information and current climatic prognoses, we invite you to visit the Oficina Nacional de Meteorología (ONAMET): http://www.onamet.gov.do/ or to call its telephone numbers: 809-788-1122 and from the interior without charge: 1-809-200-8585. ONAMET offers service 24 hours/ seven days a week.

Did you know? You can get the current report here: http://www.onamet.gov.do/?param=pronostico-general

Other references of interest:
Organización Meteorológica Mundial
Centro de Meteorología de CNN
Centro Nacional de Huracanes de Estados Unidos
Centro Nacional de Huracanes de Estados Unidos (en español)

Hurricane Season

Hurricane and cyclone season begins June 1 and concludes November 31. According to the Oficina Nacional de Meteorología (ONAMET), the critical period is between August 15 and September 15.

In the last hundred years, the country has been affected by the following hurricanes, some of which have caused great damage throughout national territory:   

• Lilis (1894)
• San Zenón (1930)
• Inés (1966)
• David (1979)
• Georges (1998)
• Odette (2003)
• Jeanne (2004)
• Alpha (2005)
• Noel (2007)
• Olga (2007) 

Did you know? Hurricanes San Zenón (1930) and David (1979) were category 5.

Did you know? After a calmer cycle of 23 years, according to researchers, cyclonic activity shifted in 1995 to a hyperactive period that could last two or three decades.

Did you know?  Cyclones are given female and male names, in alphabetical order, alternating by season and year. If a season begins with a feminine name, the next will begin with a masculine. In addition, six name lists in the three official languages of the region (Spanish, English and French), 21 names in each, have been collected, as the most active season to this point was in 1933, with 21 named tropical cyclones.

Scale of potential disaster from a hurricane

The Saffir-Simpson potential disaster scale classifies hurricanes in five categories according to the sustained surface velocity of their winds and the above-normal swells produced. It is aimed at understanding the probable damage that a hurricane would generate if it hit a coastal area without a change in its destructive power.

Hurricanes are designated “intense” from Category 3 and above. 

Recommendation for hurricane season (cyclone season)

When hurricane season begins:  

• Prepare a plan of action for your family and ensure that everyone knows what to do if there is a hurricane warning of tropical storm.
• Develop a neighborhood plan to deal with cyclones.
• Do an evaluation of the existing wood, tools, batteries, and non-perishable foods and other items that you might need.
• Identify potential dangers that there are within your home or neighborhood and take appropriate measures to correct them.
• Find out if you live in an evacuation area and discover which are the best routes to get to a safe place or place of refuge.

When hurricane or storm warnings are made:  

• Assure your personal belongings and important items, gas lamps, lanterns, candles and items that function with batteries and place new batteries in them.  
• Fill your automobile with gas. 
• Store away loose items in a safe place and eliminate objects or debris around your home.   
• Reinforce your windows, doors and ceiling. Cover sliding glass doors or French doors with wood.
• Although adhesive tapes do not prevent glass from breaking, it can prevent glass from being dispersed all over.
• Stock up on special foods for children. Ensure sufficient food for 5 or 10 days.
• Turn your fridge temperature to the absolute coldest point possible and only open when absolutely necessary.
• Prepare reserves of water before the hurricane begins.   

During the storm or hurricane:

• Remain calm. Do not pay attention to rumors.
• Within your home, remain in an interior room or one without windows
• Do not leave your home.
• Avoid the use of alcoholic beverages.
• Remain listening to the radio and battery television, all official parts of Centro de Información de Huracanes de la Oficina Nacional de Meteorología.
• If the eye of the storm or hurricane passes through your location, there will be a temporary calming of the winds. This does not mean that the danger has passed. Remain inside your home, unless you need to do some type of emergency repair, but bear in mind that after a short period of time, no more than half an hour, the wind will start again in the opposite direction and with more velocity than before.

After the hurricane or storm:  

• Remain in your house as long as possible. Streets will be full of debris and fallen electric cables that may have an electric charge.
• Turn to radio stations to listen to the most recent news.
• If you evacuated your home, do not return until your area is ready.
• Do not return: a structurally damaged house must be inspected by construction officials.
• Do not use the telephone unless there is an emergency and do not call 911 unless your life is in danger.
• Do not call to report individual electrical, water or telephone service issues. Call the authorities to report broken electrical lines and gas or water leaks.
• Potable water might be contaminated after a storm, so try to boil water that you use.
• Consume bottled water and eat non-perishable food products.
• Be careful around trees and upon turning on ovens and gas.
• Disconnect generators before restoring electricity in your home.
• Do not touch fallen electrical cables, which might be very dangerous.
• Help your neighbors to collect water on the street, to provide access to emergency services and safety inspectors.
• Do not stop in a wet area if you are operating electric equipment.
• Do not allow your children to play with water nor walk barefoot.
• If you have to live in another place while authorities repair your house, ensure that all the entrances to your home are locked, to avoid vandalism.
• Do not use gas appliances if they are covered in water.

ONAMET: www.onamet.gob.do | 809-788-1122 and from within the country without fees: 1-809-200-8585. Services are available 24 hours a day.
National emergency telephone : 911
Other useful recommendations: http://www.cdc.gov/spanish/especialescdc/huracanes/