Climate averages 1991–2020
San Juan, Peru weather
in May.
A hot, very wet month: the 10th warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a hot month in San Juan, Peru: daytime highs average 28.8°C and nights cool to about 22.9°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 271 mm of rain on roughly 27 days, which makes May a very wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 57 min on an average May day.
The nearest other city in this atlas is Iquitos (4 km away). In May its highs average 28.8°C, about as warm as San Juan, Peru, with 271 mm of rain.
Among the 24 cities listed in Peru, San Juan, Peru ranks joint 4th of 24 for the warmest May highs and joint 23rd of 24 for the driest May (rainfall, lowest first). The mean May high of those 24 cities is 23.7°C; San Juan, Peru is 5.1°C warmer than that mean.
From May to June, average highs fall by 0.6°C to 28.2°C, and monthly rainfall falls from 271 mm to 218 mm.
The annual picture
May in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
San Juan, Peru climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 30.0°C23.4°C | 23.4°C | 252 | 25.9 | 12.312 h |
| February | 30.0°C23.5°C | 23.5°C | 235 | 24.7 | 12.212 h |
| March | 29.9°C23.5°C | 23.5°C | 304 | 28.4 | 12.112 h |
| April | 29.4°C23.3°C | 23.3°C | 294 | 27.3 | 12.012 h |
| May, selected | 28.8°C22.9°C | 22.9°C | 271 | 26.7 | 11.912 h |
| June | 28.2°C22.4°C | 22.4°C | 218 | 25.0 | 11.912 h |
| July | 28.3°C22.1°C | 22.1°C | 165 | 23.3 | 11.912 h |
| August | 29.4°C22.5°C | 22.5°C | 154 | 21.8 | 12.012 h |
| September | 30.1°C23.1°C | 23.1°C | 179 | 23.5 | 12.112 h |
| October | 30.3°C23.5°C | 23.5°C | 201 | 25.8 | 12.212 h |
| November | 29.9°C23.5°C | 23.5°C | 235 | 25.8 | 12.312 h |
| December | 29.9°C23.4°C | 23.4°C | 263 | 27.2 | 12.312 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
May in nearby cities
- Iquitos in MayPeru · 4 kmHigh 28.8°C · Low 22.9°C · 271 mm rain
- Cruzeiro do Sul in MayBrazil · 433 kmHigh 28.3°C · Low 22.0°C · 134 mm rain
- Pucallpa in MayPeru · 531 kmHigh 28.6°C · Low 22.6°C · 158 mm rain
- Cuenca in MayEcuador · 642 kmHigh 17.5°C · Low 11.0°C · 100 mm rain
- Florencia in MayColombia · 653 kmHigh 25.7°C · Low 18.6°C · 244 mm rain
- Loja in MayEcuador · 658 kmHigh 20.8°C · Low 14.5°C · 82 mm rain
- Pitalito in MayColombia · 698 kmHigh 22.1°C · Low 15.1°C · 307 mm rain
- Ipiales in MayColombia · 705 kmHigh 15.7°C · Low 9.4°C · 200 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for San Juan) is explained once on the San Juan, Peru year overview and on the Sources, method and limits page.
Iquitos lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.