San Juan
September
Weather in San Juan for September 2025
Your guide to San Juan weather in September - trends and predictions
In general, the average temperature in San Juan at the beginning of September is 32 °C. As the month progressed, temperatures tended to slightly decrease, reaching an average of 31.6 °C by the end of September.
San Juan in September brings notable rainfall, with an average of 17 rainy days and a total precipitation of 128.5 mm.
Is September a good time to visit San Juan? check out the best time to travel to San Juan page.
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Temperatures
Rain 🌧️
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13
Dry days
17
Rainy days
0
Snow days
31°/26°
Temperatures
21 km/h
Avg max wind
77 %
Avg humidity
San Juan in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  32° | 2  32° | 3 33° | 4 32° | 5  31° | 6 32° | 7  32° |
| 8 30° | 9 30° | 10 31° | 11 31° | 12 33° | 13 32° | 14 33° |
| 15 33° | 16 32° | 17  30° | 18 31° | 19 31° | 20 32° | 21 32° |
| 22 31° | 23 31° | 24 32° | 25 32° | 26 31° | 27 30° | 28 33° |
| 29 31° | 30 32° |
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Temperatures trend during September in San Juan
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Partly cloudy | 32° /25° | 0.9 mm | 8 | |
| 2 Sept. | Patchy rain possible | 32° /25° | 2.5 mm | 7 | |
| 3 Sept. | Patchy rain possible | 33° /25° | 1 mm | 7 | |
| 4 Sept. | Partly cloudy | 32° /25° | 0.5 mm | 8 | |
| 5 Sept. | Cloudy | 31° /25° | 1.1 mm | 7 | |
| 6 Sept. | Partly cloudy | 32° /24° | 0.8 mm | 8 | |
| 7 Sept. | Heavy rain at times | 32° /25° | 9.2 mm | 7 | |
| 8 Sept. | Patchy rain possible | 30° /25° | 3.2 mm | 7 | |
| 9 Sept. | Patchy rain possible | 30° /25° | 11.9 mm | 7 | |
| 10 Sept. | Patchy rain possible | 31° /25° | 2.6 mm | 7 | |
| 11 Sept. | Light rain shower | 31° /24° | 4.5 mm | 7 | |
| 12 Sept. | Partly cloudy | 33° /25° | 1.9 mm | 8 | |
| 13 Sept. | Partly cloudy | 32° /25° | 0.8 mm | 8 | |
| 14 Sept. | Partly cloudy | 33° /25° | 0.4 mm | 8 | |
| 15 Sept. | Partly cloudy | 33° /25° | 0.1 mm | 8 | |
| 16 Sept. | Partly cloudy | 32° /25° | 0 mm | 8 | |
| 17 Sept. | Thundery outbreaks possible | 30° /26° | 0.6 mm | 7 | |
| 18 Sept. | Patchy rain possible | 31° /26° | 0.8 mm | 8 | |
| 19 Sept. | Partly cloudy | 31° /26° | 0 mm | 7 | |
| 20 Sept. | Patchy rain possible | 32° /25° | 8.2 mm | 7 | |
| 21 Sept. | Patchy rain possible | 32° /25° | 41.2 mm | 7 | |
| 22 Sept. | Patchy rain possible | 31° /25° | 0.2 mm | 7 | |
| 23 Sept. | Patchy rain possible | 31° /25° | 23.4 mm | 7 | |
| 24 Sept. | Patchy rain possible | 32° /25° | 2.7 mm | 8 | |
| 25 Sept. | Patchy rain possible | 32° /26° | 0.2 mm | 8 | |
| 26 Sept. | Patchy rain possible | 31° /26° | 0.5 mm | 7 | |
| 27 Sept. | Patchy rain possible | 30° /26° | 2.5 mm | 7 | |
| 28 Sept. | Patchy rain possible | 33° /26° | 3.2 mm | 7 | |
| 29 Sept. | Patchy rain possible | 31° /26° | 3 mm | 7 | |
| 30 Sept. | Patchy rain possible | 32° /26° | 0.7 mm | 8 | |
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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.
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.
What to pack to San Juan in September?
As you prepare for your trip to San Juan in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in San Juan, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Lightweight Clothing: T-shirts, blouses, shorts, skirts
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Sandals/Flip-flops: Comfortable for warm climates
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm weather
- Umbrellas/Raincoats: For rainy days
- Personal Items
- Sunscreen: High SPF for sunny destinations
- Lip Balm with SPF: To protect against chapped lips
- Insect Repellent: For destinations with mosquitos or other insects
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 ☀️
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