Last updated: August 22, 2025
In September, the average temperature in San Juan, Bolivia reaches a mild 14°C (58°F). Temperatures can vary greatly, with a minimum of -1°C (31°F) and a maximum soaring to 30°C (85°F). Expect a total precipitation of 28 mm (1.1 in) over about 5 days, contributing to an average humidity level of 60%. Perfect for those who enjoy a mix of warmth and refreshing moisture!
In September in San Juan, the average temperature is 14°C (58°F). Maximum temperatures can reach 30°C (85°F), while minimums can drop to as low as -1°C (31°F). Be prepared for a wide range of temperatures when traveling during this time!
In San Juan in September, the precipitation amount is 28 mm (1.1 in) over a period of 5 days.
In San Juan in September humidity is 60%. With an average temperature of 14°C (58°F), this humidity feels like a cool, refreshing embrace that can be invigorating for exploring outdoor attractions, although it may cause a slight chill if you're not dressed appropriately.
In San Juan in September, the maximum UV index is 14, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, so it's crucial to take precautions. For the detailed hourly UV index in San Juan, you can check here.
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 | 15°C (60°F) | 98 mm (3.9 inches) | 87% | extreme |
| February Weather | 15°C (59°F) | 117 mm (4.6 inches) | 88% | extreme |
| March Weather | 14°C (58°F) | 93 mm (3.7 inches) | 89% | extreme |
| April Weather | 14°C (57°F) | 36 mm (1.4 inches) | 87% | extreme |
| May Weather | 13°C (55°F) | 11 mm (0.4 inches) | 82% | extreme |
| June Weather | 11°C (52°F) | 4 mm (0.2 inches) | 59% | very high |
| July Weather | 11°C (51°F) | 8 mm (0.3 inches) | 47% | very high |
| August Weather | 12°C (53°F) | 7 mm (0.3 inches) | 43% | extreme |
| September Weather | 14°C (58°F) | 28 mm (1.1 inches) | 60% | extreme |
| October Weather | 16°C (60°F) | 48 mm (1.9 inches) | 67% | extreme |
| November Weather | 16°C (61°F) | 60 mm (2.4 inches) | 71% | extreme |
| December Weather | 15°C (60°F) | 116 mm (4.6 inches) | 79% | extreme |