September Weather in Puerto Rico

The tables below give the normal September 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 measures of climate are averages of historical data collected at weather stations over several decades.

One site, Pico Del Este, is much cooler and rainier 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 September temperatures in Puerto Rico

High °F	Low °F	Place	High °C	Low °C
92	71	Arecibo	33	21
84	68	Cayey	29	20
87	73	Dorado	31	23
89	74	Fajardo	32	23
89	76	Guayama	32	25
88	72	Isabela	31	22
88	73	Manati	31	23
81	67	Maricao	27	19
91	71	Mayagüez	33	22
91	73	Mona Island	33	23
72	64	Pico Del Este	22	18
91	73	Ponce	33	23
90	72	Rincón	32	22
89	78	San Juan	32	25
93	68	San Sebastián	34	20
90	66	Utuado	32	19

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

Rainfall

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

Days	Place	Inches	Millimetres
12	Arecibo	5.1	130
16	Cayey	9.0	228
14	Dorado	5.9	151
17	Fajardo	6.8	174
15	Guayama	6.9	176
16	Isabela	6.5	166
14	Manati	5.7	145
–	Maricao	11.6	296
17	Mayagüez	8.7	221
12	Mona Island	5.1	129
27	Pico Del Este	14.8	376
12	Ponce	6.4	162
–	Rincón	8.1	205
17	San Juan	5.8	147
17	Utuado	8.4	214

Relative Humidity at San Juan, Puerto Rico in September averages 79 percent in the morning and 67 percent in the afternoon.

Hurricanes and Tropical Storms

September is the height of hurricane and tropical storm activity for Puerto Rico. All areas of the country could be affected by severe weather.

Overall, the chance of a tropical storm or hurricane getting within 100 miles (165 kilometres) of Puerto Rico this month is 20 percent. There's an eight percent chance of a hurricane and a 1 to 2 percent chance of a major hurricane.