Index
Introduction
In Puerto Rico, a Caribbean island and an unincorporated territory of the United States, there is a
tropical climate, hot all year round, with a hot and muggy season from May to October and a relatively cool season from December to March, with November and April as intermediate months.
As regards to the
rains, the hot and muggy period from May to October tends to be rainy everywhere, while in the first months when the north-east trade winds blow (November and December, and partly January), the rains are still abundant on the slopes facing north and east.
In contrast, on the southern coast, there's a relative decrease in rainfall in June and July.
The north-east
trade winds, which blow all year round, but especially in the cool season, starting from November, deposit the moisture that has been picked up in the sea in the form of rain, especially on the northern side, which therefore is rainier than the southern one.
Every now and then, from December to March, the archipelago can be affected by some
frontal systems from the United States, which can bring some clouds and rains, and also a cool wind, able to lower the temperature by a few degrees, although in a less noticeable way than in Cuba and Yucatan (Mexico), which are closer to the American continent. However, the temperature in these cases can drop below 10 °C (50 °F) in the inland hilly areas, and around freezing in the mountains.
North coast
San Juan
Here are the average temperatures of the capital, San Juan, located on the north coast.
San Juan - Average temperatures (1991-2020) Month | Min (°C) | Max (°C) | Mean (°C) | Min (°F) | Max (°F) | Mean (°F) |
---|
January | 22 | 28 | 25.3 | 72 | 83 | 77.5 |
---|
February | 22 | 29 | 25.5 | 72 | 84 | 77.8 |
---|
March | 22 | 29 | 25.8 | 72 | 85 | 78.5 |
---|
April | 23 | 30 | 26.7 | 74 | 86 | 80.1 |
---|
May | 24 | 31 | 27.6 | 76 | 87 | 81.6 |
---|
June | 25 | 32 | 28.4 | 77 | 89 | 83.1 |
---|
July | 25 | 32 | 28.4 | 78 | 89 | 83.1 |
---|
August | 25 | 32 | 28.6 | 78 | 89 | 83.4 |
---|
September | 25 | 32 | 28.6 | 78 | 89 | 83.4 |
---|
October | 25 | 31 | 28.1 | 77 | 89 | 82.6 |
---|
November | 24 | 30 | 27 | 75 | 86 | 80.5 |
---|
December | 23 | 29 | 26 | 73 | 84 | 78.7 |
---|
Year | 23.9 | 30.4 | 27.1 | 75.1 | 86.7 | 81 |
---|
In
San Juan, 1,400 millimeters (55 inches) of rain fall per year, including more than 100 mm (4 in) per month between May and December, while the driest months, with about 55 mm (2.2 in) of rain per month, are February and March, that is, at the end of the period of the trade winds, when they become weaker. Here is the average precipitation.
San Juan - Average precipitationMonth | Millimeters | Inches | Days |
---|
January | 80 | 3.1 | 13 |
---|
February | 50 | 2 | 10 |
---|
March | 60 | 2.4 | 10 |
---|
April | 90 | 3.5 | 10 |
---|
May | 145 | 5.7 | 12 |
---|
June | 120 | 4.7 | 13 |
---|
July | 125 | 4.9 | 15 |
---|
August | 150 | 5.9 | 16 |
---|
September | 150 | 5.9 | 14 |
---|
October | 150 | 5.9 | 15 |
---|
November | 140 | 5.5 | 16 |
---|
December | 115 | 4.5 | 16 |
---|
Year | 1375 | 54.1 | 160 |
---|
Anyway, the rains in Puerto Rico occur mainly in the form of showers or thunderstorms, which usually do not last long, so the amount of
sunshine is always good, as can be seen in the following table.
San Juan - Sunshine hoursMonth | Average | Total |
---|
January | 7.5 | 235 | February | 8 | 230 | March | 9 | 280 | April | 9 | 270 | May | 8 | 255 | June | 8.5 | 260 | July | 9 | 280 | August | 8.5 | 270 | September | 8 | 235 | October | 7.5 | 225 | November | 6.5 | 200 | December | 7 | 215 | Year | 8.1 | 2960 |
South coast
On the south coast, the daytime temperature in winter is slightly higher because the prevailing winds, the northeast trade winds, come from the interior.
Ponce
Here are the average temperatures in Ponce, located in the central part of the southern coast.
Ponce - Average temperatures (1991-2018) Month | Min (°C) | Max (°C) | Mean (°C) | Min (°F) | Max (°F) | Mean (°F) |
---|
January | 21 | 29 | 25 | 69 | 85 | 77 |
---|
February | 20 | 29 | 25 | 69 | 85 | 77 |
---|
March | 21 | 30 | 25.3 | 70 | 85 | 77.6 |
---|
April | 22 | 30 | 26.2 | 72 | 86 | 79.2 |
---|
May | 24 | 31 | 27.4 | 75 | 88 | 81.3 |
---|
June | 25 | 32 | 28.1 | 76 | 89 | 82.6 |
---|
July | 25 | 32 | 28.3 | 76 | 90 | 83 |
---|
August | 25 | 32 | 28.3 | 76 | 90 | 83 |
---|
September | 24 | 32 | 28.2 | 76 | 90 | 82.7 |
---|
October | 24 | 32 | 27.6 | 74 | 89 | 81.7 |
---|
November | 23 | 31 | 26.7 | 73 | 87 | 80 |
---|
December | 21 | 30 | 25.5 | 70 | 86 | 78 |
---|
Year | 22.8 | 30.8 | 26.75 | 73.1 | 87.4 | 80 |
---|
Along the southern coast, which is sheltered from the trade winds, rainfall often drops below 1,000 mm (40 in) per year, and winter is particularly dry, as happens in La Parguera and Ponce; in addition, even June and July are not very rainy.
Here is the average precipitation in Ponce.
Ponce - Average precipitationMonth | Millimeters | Inches | Days |
---|
January | 25 | 1 | 6 |
---|
February | 25 | 1 | 6 |
---|
March | 40 | 1.6 | 6 |
---|
April | 55 | 2.2 | 7 |
---|
May | 95 | 3.7 | 10 |
---|
June | 65 | 2.6 | 8 |
---|
July | 65 | 2.6 | 8 |
---|
August | 110 | 4.3 | 10 |
---|
September | 150 | 5.9 | 11 |
---|
October | 160 | 6.3 | 13 |
---|
November | 95 | 3.7 | 10 |
---|
December | 35 | 1.4 | 7 |
---|
Year | 915 | 36 | 102 |
---|
The small island called
Isla Mona, to the west, is almost arid, while
Vieques, to the east, is a bit rainier, since it receives 1,070 mm (42 in) of rain per year.
Sea temperature
The
sea in Puerto Rico is warm enough for swimming 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, as can be seen from the sea temperature near San Juan.
San Juan - Sea temperatureMonth | Celsius (°C) | Fahrenheit (°F) |
---|
January | 27 | 80 | February | 26 | 79 | March | 26 | 79 | April | 27 | 80 | May | 28 | 82 | June | 28 | 83 | July | 28 | 83 | August | 29 | 84 | September | 29 | 84 | October | 29 | 84 | November | 28 | 83 | December | 27 | 81 | Year | 27.7 | 81.8 |
Hills and mountains
The interior of Puerto Rico is crossed by a mountain range called
Cordillera Central.
Here, the temperature decreases with increasing altitude: for example, in
Adjuntas, at 500 meters (1,600 feet) above sea level, highs range from 25 °C (77 °F) in winter to 29 °C (77 to 84 °F) in summer, while on
Cerro Maravilla, the fourth highest peak on the island, at 1,200 meters (3,900 feet), highs range from 20 °C (68 °F) in winter to 23 °C (73 °F) in summer.
Here are the average temperatures of Cerro Maravilla.
Cerro Maravilla - Average temperaturesMonth | Min (°C) | Max (°C) | Mean (°C) | Min (°F) | Max (°F) | Mean (°F) |
---|
January | 14 | 20 | 17 | 56 | 69 | 62.6 |
---|
February | 13 | 20 | 16.7 | 56 | 68 | 62.1 |
---|
March | 13 | 21 | 17 | 56 | 69 | 62.6 |
---|
April | 14 | 21 | 17.6 | 58 | 70 | 63.6 |
---|
May | 15 | 21 | 18.4 | 60 | 71 | 65 |
---|
June | 16 | 23 | 19.5 | 61 | 73 | 67 |
---|
July | 17 | 23 | 19.8 | 62 | 73 | 67.6 |
---|
August | 17 | 23 | 19.9 | 62 | 74 | 67.8 |
---|
September | 16 | 23 | 19.7 | 61 | 73 | 67.4 |
---|
October | 16 | 23 | 19.6 | 62 | 73 | 67.2 |
---|
November | 15 | 22 | 18.6 | 60 | 72 | 65.6 |
---|
December | 14 | 21 | 17.6 | 57 | 70 | 63.6 |
---|
Year | 15.1 | 21.8 | 18.4 | 59.2 | 71.2 | 65 |
---|
The rainiest areas are the northern slopes of the
Cordillera Central, where there is no real dry season, and in particular, those of the Caribbean National Forest (or
El Yunque): on
Pico del Este, about 1,000 meters (3,300 feet) above sea level, 4,300 mm (170 in) of rain fall per year.
Hurricanes
From June to November, the archipelago can be hit by tropical storms and
hurricanes, with a higher probability between August and October. The archipelago was hit hard by Hurricane Georges in September 1998 and by Hurricane Maria in September 2017.
However, even when they are not intense, tropical storms can produce heavy rains in mountainous areas, which can cause landslides and floods.
UpWhen to go and what to pack in
Puerto Rico