Our Climate

 

Antigua and Barbuda has a tropical maritime wet and dry type climate. The main drivers of the climate are tropical sea surface temperatures of the Pacific and Atlantic Oceans. The islands experience neither frost, snow, sleet, hail nor extremes of temperatures. A unique exception to that, however, occurred on April 16, 1993, when parts of Antigua experienced showers of hail over a 3 hour interval around sunrise.

Rainfall

There are two main seasons: the dry season - January to June and the wet season - July to December; these seasons account for 36 and 64% respectively of the annual total rainfall. The normal annual rainfall total is 1187.5 mm (46.75 in) but ranges from 574.5 mm to 1764.0 mm (22.62 to 69.45 in). The driest and wettest months are March, with 51.8 mm (2.04 in), and October, with 161.0 mm (6.34 in), respectively.

Temperature

The air temperature seldom falls below 15 °C (59 °F) and seldom rises above 35 °C (95 °F). On record, the extremes are 11.6 °C (52.9 °F) and 35.7 °C (96.3 °F). Meanwhile, the mean daily temperature is 26.9 °C (80.4 °F). The warmest and coolest months are February with 25.2 °C (77.4 °F) and August with 28.3 °C (82.9 °F).

The sea surface temperature (SST) ranges between 24.2 °C (75.6 °F) and 29.9 °C (85.8 °F) with the mean being 27.6 °C (81.7 °F). The mean rises to around 28.9 °C (84.0 °F) in September and falls to around 26.2 °C (79.2 °F) in February.

Hours of Sunshine

The hours of bright sunshine ranges from 8 to 9.5 hours on average. There is seldom ever a day without bright sunshine. The length of day (the interval between sunrise and sunset) varies from 11 hours and 6 minutes in December to 13 hours and 9 minutes in late June.

Humidity

Humidity is fairly high and uniform from month to month. The mean relative humidity is around 75% ranging from around 70% in March to around 80% in October. The relatively high humidity values are fairly deceptive as the trade winds continuously bring refreshing breezes across the islands. Thus, the high humidity is often not an issue for most persons.

Winds

The trade winds basically blow continuously across the area from the east at a mean (surface) speed of 11.5 knots (13.2 mph). The windiest month is July with 13.6 knots (15.6 mph) and the calmest is October with 9.2 knots (10.6 mph). The winds seldom exceeds 21 knots (24 mph) and are hardly ever calm.

Stronger winds do occur over open waters and elevated terrains by as much as 4 knots (4.6 mph) more than mentioned above.

Seas

Wave heights varies little - significant wave heights ranges between 1 and 2 metres (3 to 6 feet). Occasionally, seas would exceed 2.5 metres (8 feet), mainly due to long period swells generated by extra-tropical cyclones during winter and spring.

Hurricanes 

Hurricanes may occur any time from June through November; however, historically, the most likely time is mid August to mid September. There is a 25% chance of a hurricane affecting Antigua in a given year or once every four years.

Droughts

Droughts are a regular occurrence of the climate of Antigua and Barbuda. Rainfall is highly variable especially from month to month. From time to time, these droughts can be quite severe and occasionally last for multiple years.

Climate Change

Under climate change, Antigua is projected to get drier and warmer. However, the record for both rainfall and temperature show an upward trend.

 
Prepared by Dale C. S. Destin (@anumetservice)
Last updated: August 15, 2017