Antigua and Barbuda has a tropical climate, hot and humid all year round, with a relatively cool and dry season from January to mid-April, and a hot, humid and rainy season from mid-June to mid-November. In the former period, the northeast trade winds, constant winds typical of tropical climates, blow steadily and with moderate intensity, while in the latter period the winds are more irregular, and may have some breaks, increasing the feeling of sultriness. Between them there are two transitional periods: from mid November to early January (when the northeast wind starts to blow, the temperature decreases a bit and the weather gets better) and from mid-April to Mid-June (when both the temperature and the frequency of downpours gradually increase).
Antigua and Barbuda is a small state belonging to the Commonwealth. In addition to the two main islands, Antigua and Barbuda, we find some smaller islands, such as Green Island, Guiana Island, Long Island and Redonda, plus some islets.
The average daily temperature is around 25 °C (77 °F) in January and February, while it goes up to around 28 °C (82.5 °F) from June to September. Here are the average temperatures of St. John's, the capital, located on the island of Antigua.
St. John's - Average temperatures
Min (°C)222223232525252625242423
Max (°C)282829293031313131313029
Min (°F)727273737777777977757573
Max (°F)828284848688888888888684

The rainfall is not so abundant because the islands are pretty flat; the only elevation of some importance is Mount Obama, 402 meters (1,319 feet) high, in the southwest of the island of Antigua.
In Codrington, on the island of Barbuda, rainfall amounts to 1,165 mm (46 in) per year, while in Antigua, it amounts to 1,000 mm (40 in) in the north of the island (see St. John's, the airport), to 1.100 mm (43 in) in the southeastern part, and to 1,300 mm (51 in) in the southwest, near Mount Obama.
To simplify, you can divide the year into two periods, one dry from January to June, and the other rainy from July to December. The rainiest period runs from August to November, while the driest months are February and March.
Here is the average precipitation in St. John's.
St. John's - Average precipitation

The rains occur throughout the year especially in the form of downpours or thunderstorms, which could be intense, but generally do not last long, so they do not reduce too much the sunshine hours; sometimes, however, there may be a more intense wave of bad weather.
In fact, the amount of sunshine is good all year round, as can be seen in the following table.
St. John's - Sunshine


The sea temperature ranges from 26 °C (79 °F) between January and April to 29 °C (84 °F) in September, so the sea is warm enough for swimming all year round.
St. John's - Sea temperature
Temp (°C)262626262728282829282827
Temp (°F)797979798182828284828281


The greatest danger comes from tropical storms and cyclones, called hurricanes in the Caribbean area, which may pass over the islands from June to November, though they are most likely from August to October.

Best Time

The best time to visit Antigua and Barbuda is from December to April, in fact it is the driest and the least hot; in particular, the months of February and March are the least rainy of all. In May, both heat and moisture increase, but the rains are not abundant yet (except in certain years), and we are still out of the hurricane season. In the summer months, August and September are a bit rainier in comparison with June and July, and even hurricanes are more likely.

What to pack

From December to April: bring light clothing, and possibly a sweatshirt for the evening from December to March. A sun hat, sunscreen.
From May to November: bring lightweight clothing, and possibly a light sweatshirt and a light raincoat for thunderstorms. A sun hat, sunscreen.
When going to the reef, you can bring snorkeling equipment, including water shoes or rubber-soled shoes.