Dominica, an island of the Lesser Antilles belonging to the Commonwealth, 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, these 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).
Here are the average temperatures of Roseau, the capital. As you can see, there are little variations between the coolest and the warmest period.
Roseau - Average temperatures
Min (°C)222222232425252424232322
Max (°C)282828293030303130293029
Min (°F)727272737577777575737372
Max (°F)828282848686868886848684

Rainfall is abundant: in Roseau, on the west coast, 2,000 millimeters (78 inches) of rain fall per year, of which more than 200 mm (8 in) fall per month from July to November. The least rainy period is from February to April, with about 60/75 mm (2.4/3 in) per month on average. Here is the average precipitation in Roseau.
Roseau - Average precipitation

The east coast, exposed to the trade winds, receives more rain than the western one, around 2,500 mm (98 in) per year. In the interior of the island, entirely covered by hills and mountains, the rains are even more frequent and abundant, in fact, there are rainforests, and the climate can be defined as equatorial. In the northern part of the island, we find Morne Diablotins volcano, 1,447 meters (4,747 feet) high, which receives as high as 9,000 mm (354 in) of rain per year, while in the south, we find the Morne Trois Pitons National Park, a UNESCO World Heritage Site, where, in addition to an impenetrable jungle, we find geysers, rivers and waterfalls, as well as a hot lake, the Boiling Lake.
The rains in Dominica occur throughout the year as 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.
Roseau - Sunshine


The sea in Dominica is warm enough to swim in all year round: the water temperature ranges from 26 °C (79 °F) in February and March to 29 °C (84 °F) in September and October. Here are the average sea temperatures.
Dominica - Sea temperature
Temp (°C)272626272828282829292827
Temp (°F)817979818282828284848281


The greatest danger comes from tropical storms and cyclones, called hurricanes in the Caribbean area, which may pass over the island from June to November, though they are most likely from August to October. Two hurricanes that have been particularly destructive on this island were David in late August 1979 and Maria in September 2017.

Best Time

The best time to visit Dominica is from February to April, since it is the least rainy period of the year. December and January are still quite rainy months, though less so than the period from July to November, which has the greatest risk of heavy showers and thunderstorms (as well as of hurricanes). It is worth while to recall that the west coast, where Roseau is located, is more sheltered.

What to pack

All year round: bring light, tropics-friendly clothes of natural fabric, a sun hat, sunscreen, and possibly a light sweatshirt and a light raincoat for thunderstorms. From December to March, you can add a light sweatshirt for the evening.
When going to the reef, you can bring snorkeling equipment, including water shoes or rubber-soled shoes. When going hiking in the mountains, bring hiking shoes, a raincoat and a sweatshirt.