Last updated: August 31, 2025
In San Isidro, Puerto Rico, the average temperature in May is a warm 27°C (80°F). Expect a pleasant range with minimum temperatures around 23°C (73°F) and highs reaching 32°C (90°F). However, be prepared for occasional rain, as 64 mm (2.5 in) of precipitation typically falls over 13 days. With an average humidity of 75%, it's a perfect time to enjoy the vibrant atmosphere, but don't forget your sunscreen!
In May in San Isidro, the average temperature is 27°C (80°F), with maximums reaching 32°C (90°F) and minimums dropping to as low as 23°C (73°F). This climate makes it an ideal time for travelers looking to enjoy warm weather while exploring the vibrant sights of San Isidro.
In San Isidro in May, the precipitation amount is 64 mm (2.5 in) spread over 13 days.
In San Isidro in May humidity is 75%. With an average temperature of 27°C (80°F), this humidity feels like a warm, enveloping blanket that makes traveling a bit more challenging, as every step can leave you feeling sticky and in need of frequent hydration breaks.
In San Isidro in May, 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 Isidro, you can check here.
UV Risk Categories
Weather in San Isidro varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in San Isidro, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 25°C (77°F) | 38 mm (1.5 inches) | 76% | very high |
| February Weather | 25°C (77°F) | 43 mm (1.7 inches) | 75% | extreme |
| March Weather | 25°C (77°F) | 67 mm (2.6 inches) | 74% | extreme |
| April Weather | 26°C (78°F) | 56 mm (2.2 inches) | 75% | extreme |
| May Weather | 27°C (80°F) | 64 mm (2.5 inches) | 75% | extreme |
| June Weather | 27°C (81°F) | 68 mm (2.7 inches) | 77% | extreme |
| July Weather | 28°C (82°F) | 87 mm (3.4 inches) | 80% | extreme |
| August Weather | 28°C (82°F) | 99 mm (3.9 inches) | 80% | extreme |
| September Weather | 28°C (82°F) | 173 mm (6.8 inches) | 79% | extreme |
| October Weather | 27°C (81°F) | 145 mm (5.7 inches) | 78% | extreme |
| November Weather | 26°C (80°F) | 106 mm (4.2 inches) | 78% | very high |
| December Weather | 26°C (78°F) | 51 mm (2.0 inches) | 76% | very high |