Climate averages 1991–2020
San Juan, Peru weather
in December.
A hot, very wet month: the joint 5th warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a hot month in San Juan, Peru: daytime highs average 29.9°C and nights cool to about 23.4°C. By daytime temperature it is the joint 5th warmest of the 12 months.
Expect about 263 mm of rain on roughly 27 days, which makes December a very wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 20 min on an average December day.
The nearest other city in this atlas is Iquitos (4 km away). In December its highs average 29.9°C, about as warm as San Juan, Peru, with 263 mm of rain.
Among the 24 cities listed in Peru, San Juan, Peru ranks joint 4th of 24 for the warmest December highs and joint 21st of 24 for the driest December (rainfall, lowest first). The mean December high of those 24 cities is 24.6°C; San Juan, Peru is 5.3°C warmer than that mean.
From December to January, average highs rise by 0.1°C to 30.0°C, and monthly rainfall falls from 263 mm to 252 mm.
The annual picture
December 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 | 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, selected | 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
December in nearby cities
- Iquitos in DecemberPeru · 4 kmHigh 29.9°C · Low 23.4°C · 263 mm rain
- Cruzeiro do Sul in DecemberBrazil · 433 kmHigh 29.4°C · Low 22.7°C · 243 mm rain
- Pucallpa in DecemberPeru · 531 kmHigh 29.6°C · Low 23.3°C · 289 mm rain
- Cuenca in DecemberEcuador · 642 kmHigh 18.3°C · Low 11.5°C · 172 mm rain
- Florencia in DecemberColombia · 653 kmHigh 27.2°C · Low 18.4°C · 143 mm rain
- Loja in DecemberEcuador · 658 kmHigh 21.3°C · Low 14.7°C · 146 mm rain
- Pitalito in DecemberColombia · 698 kmHigh 23.2°C · Low 15.1°C · 227 mm rain
- Ipiales in DecemberColombia · 705 kmHigh 16.1°C · Low 9.5°C · 269 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.