General Overview

Antigua and Barbuda enjoys a tropical marine climate, which means that it welcomes visitors with humid and hot conditions (primarily) almost throughout the year. The good news is that the northeastern trade winds that blow on the islands help push down the heat index and the humidity levels as they pass over the warm sea, lowering the perceived temperature to more tolerable and pleasant levels. On average, they blow at speed clocking in the range of 19kph (around 12mph) and up to 29 kph (18mph) in July.

In addition to all that, the tropical location of the Leewards Islands sovereign state and its proximity to the Atlantic Ocean and the Caribbean Sea affect the climate, creating two predominant seasons, a dry and a wet season (which is also the hurricane season). The first starts in January and lasts through May, while the second runs from June through December.

Regarding the average daily temperatures, they range from 25oC (77oF) and can climb to over 28oC (almost 83oF) in January and August, respectively. The highest average temperatures are experienced in the summer months (from June to August), when the weather is humid, wet and hot, and reach above 31oC (88oF), with rarely rising over 34oC (92oF). In fact, the highest temperature ever recorded in Antigua and Barbuda is about 35oF (95oF) in 1995 in the island’s capital, St. John’s, while the coldest it has ever been is 16oC (61oF) in 1974, in the same region.

Average Daily Temperatures

January, February, and March are the coldest months of the year for Antigua and Barbuda, averaging around 25.5oC (77.8oF), while their hottest siblings are the months of June through October, when the average daily temperatures are around 28oC (82.5oF). The following table shows the average temperatures in the capital of Antigua and Barbuda, St. John’s.

Average temperatures (St. John’s)

Rainfall

Being rather flat islands, Antigua and Barbuda receive quite a lot of rainfall and often downpours. However, the average rainfall on both islands is still quite lower than other Caribbean destinations. That being said, the southwest of Antigua receives approximately 1,300 millimetres (51 inches) of rain annually (near Mount Obama). In the areas around St. John’s in the north of the island, rainfall amounts to nearly 1,000 millimetres (40 inches) and about 100 kilometres more (3 inches) in the southern-eastern regions. As of Barbuda, rainfall in Codrington amounts to about 1,165 millimetres (46 inches) annually.

Average precipitation (St. John’s)

Regarding the number of rainy days each month has, the least rainy months are February through June, which enjoy a single-digit number of days with rain (averaging 8 days monthly). The rainiest period is between July and December, when you can expect around 12 days of rain monthly.

Days of rain (St. John’s)

Humidity & Wind

The most humid month in a year is October, with neary 73% relative humidity. The least humid month in Antigua and Barbuda is March, with almost 65% relative humidity. In general, the nation has above average humidity year-round.

Considering the wind, it is moderate in Antigua and Barbuda, at least most of the time. The speed reaches a maximum of around 10.2 knots (or 18.8 kph or 11.7 mph) in June, which is perceived as a gentle breeze. The rest of the summertime is also an ideal season for wind-powered water sports and activities, with the highest maximum sustained winds (the more longer-lasting wind for the day) being experienced in early August (around 15.7 knots, which is felt as a moderate breeze).

Sunshine Hours

The frequent thunderstorms and downpours do not affect the amount of daily sunshine. Although intense sometimes, they do not last long (the storms) and enable visitors to enjoy their outdoor ventures and other experiences with lots of sunshine as their ally almost throughout the year (around 8 hours of sunshine daily on average).

Sunshine hours (St. John’s)

Sea Temperatures

Antigua and Barbuda greets travellers with warm seas all year round, with water temperatures ranging in the 28oC (82oF) neighbourhood, especially after May and until the end of the year. But, even during the period from January through May, the water temperature is nice and pleasant at around 26oC (80oF), making Antigua and Barbuda a dreamland for water-sports enthusiasts!

Sea temperature (St. John’s)

Weather Hazards & Hurricane Season

The greatest danger for Antigua and Barbuda comes from the hurricanes (tropical cyclones and storms) that often hit the Caribbean region. If one strikes the Caribbean destinations, chances are it will pass over Antigua and Barbuda between August and October, though the official hurricane season is from June to November.

Nevertheless, it is more likely Antigua and Barbuda is affected by anticyclones or tropical storms rather than hurricanes, primarily because the islands sit outside the main hurricane strike zone. According to statistics, Antigua and Barbuda are struck by one hurricane per year (category 1 or 2) between June and October.

Other than that, the islands are also prone to floods, droughts (due to lack of freshwater sources), and earthquakes, while the fact that they are part of the Lesser Antilles volcanic arc also makes them prone to volcanic eruptions.