August Weather in Puerto Rico

The tables below give the normal August temperatures and rainfall for cities and popular vacation spots in Puerto Rico. There's also information here on hurricanes, plus this month's average humidity and ocean temperature.

The temperature and rain measurements are averages based on weather data collected from 1991 to 2020 for the US National Centers for Environmental Information.

One site, Pico Del Este, is much cooler than others on the list. That's because it's a high mountain peak, at 3448 feet (1050 metres) elevation, in the El Yunque Caribbean National Forest.

Temperature

Average August temperatures in Puerto Rico

High °F	Low °F	Place	High °C	Low °C
89	73	Aguirre	31	23
82	68	Aibonito	28	20
91	71	Caguas	33	21
89	78	Ceiba	32	25
88	74	Dorado	31	23
90	77	Guayama	32	25
87	73	Isabela	30	23
89	72	Juncos	31	22
91	76	La Parguera	33	24
92	70	Lajas	33	21
89	76	Levittown	31	25
87	72	Manati	31	22
80	68	Maricao	27	20
90	72	Mayagüez	32	22
93	73	Mona Island	34	23
71	64	Pico Del Este	22	18
92	69	Ponce	33	21
89	78	San Juan	32	25

Ocean Temperature at San Juan, Puerto Rico averages 83 degrees Fahrenheit (28 degrees Celsius) in August.

Rainfall

Average total precipitation in August. Days are when it rains at least 0.01 inches (0.25 millimetres).

Days	Place	Inches	Milli­metres
10	Aguirre	5.3	134
14	Aibonito	5.5	141
19	Caguas	8.2	209
18	Ceiba	4.3	110
14	Dorado	6.3	161
19	Guayama	7.1	180
16	Isabela	6.7	171
17	Juncos	7.2	183
–	La Parguera	4.3	110
12	Lajas	4.9	124
–	Levittown	7.7	196
15	Manati	5.4	136
–	Maricao	11.6	296
15	Mayagüez	6.8	173
11	Mona Island	4.2	107
10	Ponce	4.6	116
20	San Juan	6.3	160

Relative Humidity at San Juan, Puerto Rico in August averages 80 percent in the morning and 67 percent in the afternoon.

Hurricanes and Tropical Storms

With hurricane season in full swing, there's about a two percent chance of a hurricane approaching Puerto Rico in August. The likelihood of a named tropical coming within 100 miles (165 kilometres) of land is 12 percent for most of Puerto Rico and 14 percent in the southeast.