easeweather.com
San Juan
AguadillaBayamónMayagüezPonce
San Juan
More Locations
Puerto Rico weather

Weather in San Juan for September 2025

Your guide to San Juan weather in September - trends and predictions

    Official Weather Alert ⚠️

  • Hydrologic Outlook - See hour by hour.

    • Temperatures

  • Until now, September 2025 in San Juan is slightly cooler than the historical average by -1.2 °C.

  • Expect cooler weather in the next days in San Juan with the forecast suggesting a temperature of 30.4 °C, lower than the historical average.

  • In general, the average temperature in San Juan at the beginning of September is 31.6 °C. As the month progressed, temperatures tended to moderately fall, reaching an average of 30.9 °C by the end of September.

    • Rain 🌧️

  • San Juan in September brings notable rainfall, with an average of 17 rainy days and a total precipitation of 128.5 mm.

Average dry days
13
Dry days
Average rainy days
17
Rainy days
Average snowy days
0
Snow days
Average temperatures
31°/26°
Temperatures
Average wind speed
21 km/h
Avg max wind
Average humidity
77 %
Avg humidity

San Juan Weather September

Move between months or click on a day
August
October
Mon.Tue.Wed.Thu.Fri.Sat.Sun.
1
Partly cloudy
32°
2
Patchy rain possible
32°
3
Patchy rain possible
32°
4
Partly cloudy
32°
5
Cloudy
31°
6
Partly cloudy
31°
7
Heavy rain at times
31°
8
Patchy rain possible
30°
9
Patchy rain possible
31°
10
Patchy light rain with thunder
31°
11
Light rain shower
31°
12
Partly cloudy
32°
13
Partly cloudy
32°
14
Partly cloudy
32°
15
Partly cloudy
33°
16
Weather Alert Moderate rain
31°
17
Weather Alert Heavy rain
29°
18
Moderate rain
30°
19
Heavy rain
30°
20
Moderate rain
31°
21
Partly cloudy
30°
22
Partly cloudy
30°
23
Sunny
31°
24
Sunny
30°
25
Patchy rain possible
31°
26
Patchy rain possible
31°
27
Patchy rain possible
31°
28
Patchy rain possible
31°
29
Patchy rain possible
30°
30
Patchy rain possible
32°

Temperatures trend during September in San Juan

See the weather trend as well as the moving average line

September weather in San Juan day by day

Click on a date for more information
August October
Date Weather Temperatures Rain UV More
1 Sept. Partly cloudy
Partly cloudy
 32° /25° 0.6 mm 7
2 Sept. Patchy rain possible
Patchy rain possible
 32° /25° 1.7 mm 7
3 Sept. Patchy rain possible
Patchy rain possible
 32° /25° 0.7 mm 7
4 Sept. Partly cloudy
Partly cloudy
 32° /26° 0.3 mm 7
5 Sept. Cloudy
Cloudy
 31° /26° 6.8 mm 7
6 Sept. Partly cloudy
Partly cloudy
 31° /25° 0.5 mm 7
7 Sept. Heavy rain at times
Heavy rain at times
 31° /25° 13.8 mm 7
8 Sept. Patchy rain possible
Patchy rain possible
 30° /26° 5.7 mm 7
9 Sept. Patchy rain possible
Patchy rain possible
 31° /25° 7.9 mm 7
10 Sept. Patchy light rain with thunder
Patchy light rain with thunder
 31° /25° 8.3 mm 7
11 Sept. Light rain shower
Light rain shower
 31° /25° 4.2 mm 7
12 Sept. Partly cloudy
Partly cloudy
 32° /25° 1.3 mm 8
13 Sept. Partly cloudy
Partly cloudy
 32° /25° 1.3 mm 8
14 Sept. Partly cloudy
Partly cloudy
 32° /25° 5.7 mm 7
15 Sept. Partly cloudy
Partly cloudy
 33° /25° 5.9 mm 7
16 Sept. Moderate rain
Moderate rain
 31° /28° 11.3 mm 2.7
17 Sept. Heavy rain
Heavy rain
 29° /27° 43.6 mm 2.6
18 Sept. Moderate rain
Moderate rain
 30° /27° 15.1 mm 2
19 Sept. Heavy rain
Heavy rain
 30° /27° 21.5 mm 2.5
20 Sept. Moderate rain
Moderate rain
 31° /26° 9 mm 0.2
21 Sept. Partly cloudy
Partly cloudy
 30° /26° 0.1 mm 7
22 Sept. Partly cloudy
Partly cloudy
 30° /25° 0.1 mm 7
23 Sept. Sunny
Sunny
 31° /25° 0 mm 7
24 Sept. Sunny
Sunny
 30° /25° 0.1 mm 7
25 Sept. Patchy rain possible
Patchy rain possible
 31° /26° 2.4 mm 6
26 Sept. Patchy rain possible
Patchy rain possible
 31° /25° 0.5 mm 6
27 Sept. Patchy rain possible
Patchy rain possible
 31° /25° 2.7 mm 6
28 Sept. Patchy rain possible
Patchy rain possible
 31° /25° 0.3 mm 6
29 Sept. Patchy rain possible
Patchy rain possible
 30° /26° 0.1 mm 6
30 Sept. Patchy rain possible
Patchy rain possible
 32° /26° 0.7 mm 8
Next
Important Notice
Our weather forecast for San Juan in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the San Juan forecast closer to your planned date for the most up-to-date weather information.
Change Month
‹
›

San Juan in September - FAQ

What are the expected maximum and minimum temperatures in San Juan during September?
During September, expect a variety of temperatures with highs around 31° and lows near 26°, suitable for diverse activities and preferences.
How much rainfall should be expected in San Juan during September?
Significant rainfall exceeding 128.5 mm is expected in San Juan during September, occurring over more than 17 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in San Juan during September?
The average wind speed in San Juan during September is 21 km/h, suggesting breezy to windy conditions, depending on your activities.

September rainfall patterns in San Juan

Explore the daily rainfall trends and prepare for San Juans September weather 💧

UV exposure in San Juan during September

Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Provinces in San Juan
Select a province for an accurate weather forecast
San Juan Antiguo BarrioSan Juan de la Maguana
Top locations in San Juan
Select a location for an accurate weather forecast
Punta Caña
More Locations

Quick links

More San Juan weather pages
You are here
Location coordinates Where is San Juan?

Get accurate weather forecasts for San Juan, located at latitude 18.466 and longitude -66.106. Stay updated with localized weather information tailored for San Juan.

Found a mistake?
We appreciate your attention to details. Tell us here.