Last updated: August 27, 2025
In May, the average temperature in San Mateo, Peru hovers around 3°C (37°F), with extremes ranging from a chilly -7°C (21°F) to a mild 11°C (52°F). Be prepared for some wet days, as 124 mm (4.9 in) of precipitation typically falls over 25 days, all while the air maintains a high average humidity of 85%.
In May in San Mateo, the average temperature is 3°C (37°F), with maximums reaching up to 11°C (52°F) and minimums dropping as low as -7°C (21°F). Be sure to pack warm clothing and layers if you plan to visit during this time.
In San Mateo in May, the precipitation amount is 124 mm (4.9 in) over the course of 25 days.
In San Mateo in May, humidity is 85%. With an average temperature of 3°C (37°F), this humidity feels like a chilling blanket enveloping you, making traveling uncomfortable as your clothes cling to your skin and the cold air bites at your face.
In San Mateo 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 Mateo, you can check here.
UV Risk Categories
Weather in San Mateo varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in San Mateo, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 3°C (38°F) | 220 mm (8.7 inches) | 91% | extreme |
| February Weather | 3°C (39°F) | 251 mm (9.9 inches) | 90% | extreme |
| March Weather | 3°C (38°F) | 291 mm (11.5 inches) | 91% | extreme |
| April Weather | 3°C (38°F) | 164 mm (6.5 inches) | 89% | extreme |
| May Weather | 3°C (37°F) | 124 mm (4.9 inches) | 85% | extreme |
| June Weather | 2°C (36°F) | 50 mm (2.0 inches) | 65% | extreme |
| July Weather | 2°C (35°F) | 44 mm (1.7 inches) | 47% | extreme |
| August Weather | 2°C (36°F) | 59 mm (2.3 inches) | 38% | extreme |
| September Weather | 3°C (37°F) | 120 mm (4.7 inches) | 40% | extreme |
| October Weather | 3°C (38°F) | 174 mm (6.8 inches) | 56% | extreme |
| November Weather | 4°C (39°F) | 232 mm (9.1 inches) | 76% | extreme |
| December Weather | 4°C (39°F) | 244 mm (9.6 inches) | 90% | extreme |