As of 00:42 AST

Guaynabo, PR weather in September

82°

Guaynabo, Sunday, 9 August, 00:42

Clear. Feels like 89°. High 90°, low 77°.

Pressure30.03 inHg

Wind4 mph SE

Humidity81%

Visibility6.2 mi

Dew point76°

See detailed hourly forecast

In September, Guaynabo, PR averages a high of 87.8° and a low of 75.2°. About 4.6 inches of precipitation fall over the month (21 wet days). The record high is 95.2° (2023) and the record low 70.9° (2022). Normals are computed over the last 60 years.

Day	High	Low	Chance of precip.	Record high	Record low
1	88.5°	75.4°	70%	93° (2025)	72.7° (1974)
2	88.2°	75.2°	72%	93.2° (2023)	72.3° (1986)
3	88.5°	75.4°	60%	92.7° (1967)	73.2° (1971)
4	88.5°	75.4°	57%	94.8° (2021)	72.9° (1982)
5	88.2°	75.4°	68%	95.2° (2023)	71.6° (1961)
6	88.2°	75.4°	65%	93° (2012)	72.9° (2018)
7	88.2°	75.2°	65%	93.4° (2023)	72° (2022)
8	88.3°	75.4°	67%	93.2° (2022)	73° (1984)
9	88.2°	75.4°	58%	93.6° (2021)	72.5° (2018)
10	88°	75.4°	58%	94.1° (2021)	72.7° (1984)
11	88°	75.2°	60%	93.4° (2025)	73.2° (1982)
12	88.3°	75.2°	65%	94.5° (1971)	73° (1967)
13	88°	75.4°	65%	94.5° (2023)	72.9° (1967)
14	87.8°	75.4°	67%	94.3° (2023)	73.4° (1966)
15	87.4°	75.2°	77%	94.5° (2023)	73° (1973)
16	87.8°	75°	63%	93.7° (2024)	73° (2017)
17	87.8°	75.2°	68%	92.8° (2023)	72.1° (1961)
18	87.3°	75.2°	77%	91.6° (2023)	72.5° (1974)
19	87.6°	75.2°	82%	91° (2018)	73° (1962)
20	87.6°	74.8°	78%	93.4° (2018)	71.2° (2020)
21	87.4°	75°	73%	95° (2019)	71.8° (2020)
22	87.3°	75°	70%	94.6° (2021)	73.4° (1970)
23	87.4°	75°	65%	92.3° (2024)	71.8° (1984)
24	87.6°	75°	75%	94.6° (2023)	72.3° (1974)
25	87.4°	75°	75%	92.8° (2024)	72.3° (1974)
26	87.6°	75°	68%	92.1° (1969)	72.5° (1975)
27	87.1°	75°	70%	92.5° (1971)	73° (1964)
28	87.1°	74.7°	75%	92.3° (2025)	72° (1998)
29	87.4°	74.8°	68%	92.7° (2015)	70.9° (2022)
30	87.3°	74.8°	72%	91.9° (2025)	71.6° (2022)