Last updated: August 27, 2025
In September, the average temperature in San Juan, Peru hovers around 15°C (58°F), making it a comfortable time to explore this region. Expect a minimum of 11°C (53°F) and a maximum of 19°C (67°F) throughout the month. With only 6 mm (0.2 in) of precipitation over 0 days, you’re likely to enjoy plenty of dry weather. The average humidity is around 74%, adding a pleasant feel to the air as you soak in the sights.
In September in San Juan, the average temperature is 15°C (58°F). The maximum can reach 19°C (67°F), and the minimum can be as low as 11°C (53°F). It's a comfortable time to visit, making it perfect for outdoor activities and exploring the area.
In San Juan in September, the total precipitation amount is 6 mm (0.2 in), spread over a duration of 0 days.
In San Juan in September, humidity is 74%. With an average temperature of 15°C (58°F), this humidity feels like a warm, enveloping blanket, making travel feel both refreshing yet slightly sticky, encouraging you to seek the shade or enjoy water-based activities.
In San Juan in September, the maximum UV index reaches 13, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's crucial to take protective measures. For detailed information, you can check the Hourly UV Index in San Juan.
UV Risk Categories
Weather in San Juan varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in San Juan, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 21°C (70°F) | 14 mm (0.6 inches) | 85% | extreme |
| February Weather | 21°C (71°F) | 11 mm (0.4 inches) | 85% | extreme |
| March Weather | 21°C (70°F) | 5 mm (0.2 inches) | 86% | extreme |
| April Weather | 19°C (67°F) | 3 mm (0.1 inches) | 88% | extreme |
| May Weather | 17°C (63°F) | 5 mm (0.2 inches) | 85% | very high |
| June Weather | 16°C (61°F) | 9 mm (0.4 inches) | 78% | very high |
| July Weather | 15°C (59°F) | 11 mm (0.4 inches) | 75% | very high |
| August Weather | 14°C (58°F) | 6 mm (0.2 inches) | 73% | extreme |
| September Weather | 15°C (58°F) | 6 mm (0.2 inches) | 74% | extreme |
| October Weather | 15°C (60°F) | 5 mm (0.2 inches) | 78% | extreme |
| November Weather | 17°C (63°F) | 4 mm (0.2 inches) | 82% | extreme |
| December Weather | 19°C (66°F) | 6 mm (0.2 inches) | 83% | extreme |