Peru: Weather Overview
Peru sits on the northwest coast of South America and is home to part of the Andes Mountains. Its southern tip touches the equator. The countryâs location and its diverse and dramatic landscape mean Peru is home to many different climates. Peruâs incredible landscape and varied climate have led to an astonishingly high level of biodiversity. If somewhat simplified, Peru can be split into three climatic regions: the arid coast, along the west; the Andes, in central Peru; and the tropical lowlands in the east. Generally, Peruâs weather is hot and dry towards the west, and hot and wet towards the east. Peruâs equatorial location means that there is little seasonal variation in the temperature in most places. Between seasons, the greatest difference is seen in rainfall.
The eastern lowlands make up 60% of Peru. They have an equatorial climate which allows a large section of the Amazon Rainforest to thrive. High heat, high humidity and high rainfall rule year round. The average high sits around 32°C, and the average low around 22°C, year round. This is very hot and you may find it uncomfortable, especially as the humidity pushes the perceived temperature right up. There is a short dry season between June and August, but dry weather never lasts for long in tropical locations. Rainfall can be expected any day and, during the wet season, on most days. This can sometimes mean flooding and can play havoc with the region's roads as they are eroded or affected by landslides. Sunshine levels are kept at a moderate level by the frequent rain, but when it isnât raining it is often sunny. It is sunniest towards the end of the dry season and can be very gloomy towards the end of the wet season. It is probably best to visit the rainforest in the dry season, not only because it rains less but because this means humidity is slightly lower so the heat is easier to bear. Mosquitoes are a problem year-round in this region so donât forget your repellant!
Stretching along Peruâs Pacific coast is a narrow strip of warm, semi-arid land. It sits in the rainshadow of the Andes, which means the mountains block the rain-bearing prevailing winds from reaching that area. The weather here is largely determined by the Pacificâs Humboldt Current, a cold current that flows up from the southern tip of South America. It has a significant cooling effect on this region, generally keeping temperatures in the 20s, and also results in low rainfall. This effect lessens the further north you travel as the Humboldt Current warms up. The cool water combined with the heat means that fog and mist are regular features of coastal Peru. This region is seasonal, though the seasons are not highly distinct, and as Peru is in the Southern Hemisphere the seasons are reversed to those in the Northern Hemisphere.
Summer, from January till March, sees daily average high temperatures in the mid to high 20s. Towards the south, it rarely gets above 29°C, while to the north it regularly gets up to 35°C. Due to low humidity, it cools down significantly at night, though locations directly on the coast have higher humidity and often see a temperature difference of only 5°C between day and night. Clear skies are common throughout the summer but fog can always develop. Rainfall is very low. Much of the coast sees no rain, and if it falls at all it usually only does so in the evening or at night. For the northern reaches of the coast, however, December is the start of the ârainy seasonâ, which sees the regionâs only reliable annual rainfall, albeit very little. El Nino does sometimes bring freak high rainfall to the coast of Peru and sometimes causes flooding.
Lima has a central location. It is hottest in February with an average high of 27°C and an average low of 20°C. Sunshine levels reach an average of seven hours per day and the sea temperature gets up to 23°C. Rainfall is negligible.
Autumn, in April and May, is much milder, with temperatures in the mid-20s in the day, not reaching towards 30°C. Again, it tends to be cooler in the south than in the north. Sunshine levels drop and fog and mist become more common. Rainfall, if there was any in the first place, lessons.
Winter, from June till September, is cooler but still very warm. It sees daily average highs around the low 20s and high teens. Overcast skies and foggy or misty weather becomes the norm so sunshine levels dwindle. In Lima, it gets down to an average of one hour per day. Rainfall remains exceptionally low but the fog often makes it feel quite damp. By the end of the season, the sea temperature reaches its annual low of around 17°C. However, this is as warm as the Atlantic gets around the UK in the height of summer.
Spring, from October till December, gets hot again. The average high temperature climbs up into the mid-20s again. Fog and mist lessen and sunshine increases. Rain? What rain?
Climates always become cooler at increased altitudes. In the Andes, a temperate climate with moderate and unvarying temperatures can be found in the foothills and valleys, while higher up temperatures become mild and in the highest peaks glaciers survive and snowfall can be expected year round. Seasonal differences are brought about by changes in rainfall. The wet season lasts from September till April, peaking between January and March. In lower-lying areas, rainfall levels are not as high as those seen in tropical regions, but rain falls frequently in the wet season. Higher up, precipitation is much higher, with some areas receiving up to 10,000mm of rain per year. Mountain lakes generally attract more rain than surrounding areas. Thunderstorms and other, more extreme, storm weather like hail and high winds, are more frequent at the start of the wet season.
Arequipa, at 2,380m in the Andes in the south of Peru, has a subtropical highland climate that is warm year round. It sees an average high temperature of around 22°C all year round. Temperature differences between seasons do differ at night, as slightly drier weather in the winter allows for a greater drop in temperature at night than in the summer. However, the drop in temperature in these regions is huge year round as it is so arid. In the summer the average low can be expected to be around 8°C while in the winter it sits around 4°C. It can fall below freezing. As Arequipa sits in the south, rainfall is still very low, but in the wet season, it does receive reliable, small amounts of rain. The wettest month is February with an average of 38mm of rain distributed between twenty days with rainfall.
Cusco, at 3,300m, also has a subtropical highland climate, with mild temperatures year-round and seasonal rainfall. The average high sits just below 20°C at all times and the average low sits at 7°C in the summer and falls to 0°C in the winter. Even at this elevation, the warmth means that snow is highly unlikely at any time of year, though hail and frost occur regularly. As Cusco is at a higher elevation and is further north than Arequipa, rainfall is much higher in the wet season, with significant showers falling throughout the wet season. January is its wettest month with a monthly average of 153mm of rain falling on around eighteen days in the month.