Lima’s weather and climate isn’t what one would expect when travelling to a city located just 12° south of the equator. It’s usually described as mild and warm throughout the year without noteworthy rain making Lima one of the driest capitals in the world. The average temperatures range from 12°C to 18°C (low) and 24°C to 28°C (high). Relative humidity is very high, and produces quickly passing morning fogs from December to April and persistent low clouds and mist from May to November. Sunny, moist and warm summers (December - April) are followed by cloudy, damp and cool winters (May - November).

The reason for Lima’s unusual weather conditions is its location. The capital of Peru is lying directly at the Pacific Ocean in an arid region of plains that rise to the east to the foothills of the Andes Mountains. The cold Humboldt Current which runs along most of the Peruvian and Chilean coast moderates the heat of the tropical sun, but at the same time produces high humidity with clouds and mist. The Andes Mountains to the east of the city prevent the tropical climate including storms and rains from the Amazon basin reaching the coast.

The Humboldt Current was named after Alexander von Humboldt and is one of the major up welling systems of the world, supporting an extraordinary richness of marine life. The Peruvian coast is one of the richest areas of the world in terms of biomass and diversity. Water temperatures are generally very low (between 13 to 14º C in winter and 15 to 17º C in summer) and swimming is a really ‘refreshing’ experience...

The seasons in Lima are very easy described, as the city only has two notable distinctive weather conditions: Summer from December to April and winter from May to November.

By the end of November or the beginning of December the mist and persistent clouds lighten, humidity lowers and temperatures increase. Day by day Limeños experience less overcast days and it seems Lima slowly awakes from a deep slumber. Finally around Christmas summer arrives in the capital of Peru. Besides some quickly passing early morning fogs it’s warm and sunny, normally never too hot, but still humid. Temperatures reach a very pleasant 28 °C by day and 18 °C by night. Unfortunately already by April summer comes to an end and winter is almost around the corner.

From April onwards temperatures decrease, humidity raises and cool air moves in from the ocean and condenses in the atmosphere. By May Lima once again is covered in a blanket of clouds, mist and fog. On many winter days morning and evening drizzle, locally called garúa, is a common occurrence. Temperatures in winter reach around 17 °C by day and 11 °C by night. But please don’t let yourself be fooled by these quite moderate numbers. There is always a difference between the real and the felt temperatures. Grey sky for weeks, high humidity, no heating in most buildings and once in a while drizzle makes winter in Lima at least for Limeños, and as we also heard from a few tourists a quite clammy and cool experience. So it’s not much of a surprise to find scarfs, gloves, woolen jumpers, warm jackets and winter boots in the stores. So better pack a nice, warm sweeter and a pair of thick socks.

To make the weather and climate for foreigners a little bit more confusing, there isn’t only one real established climate in Lima, especially in the winter months. The cold Humboldt Current and the rise in elevation from sea level in the west to the spur of the Andes Mountains in the east create several micro-climates. There are big differences between the districts directly on the coast and those that are further away to the east. For example, in winter areas like Miraflores, San Isidro, Barranco, Chorrillos and as well parts of Surco will be cool, damp and foggy as they are close to the ocean. Going away to the east from the sea you will notice step by step a change to drier and warmer weather.

Please note that Lima has a quite high UV radiation throughout the year. Even in winter, when clouds and mist cover the sky and no one thinks about it, the UV radiation can be moderate to high. This can unexpectedly cause skin irritations, bad sunburns and other skin damages. While a sun lotion with a high protection level should be a must for everyone in summer, anybody with sensitive or pale skin might consider using it also in the winter months!

Around the world we are currently experiencing climate changes. Lima is no exception. While lots of people in the northern hemisphere are talking about global warming this doesn’t seem to apply to Lima. It looks like a change to more extreme conditions. Some of the older generation still remember times when winter was instead of seven or eight month only three or four month long and there was some sort of spring and autumn with a less cloudier sky, not as much humidity and much more sun and warmth. In contrast temperatures in summer would never exceed 30°, something that happened in the last few years quite often. This might not be scientific proven, but at least worth a thought.

The Peruvian National Service for Meteorology and Hydrology publishes weather forecasts and weekly weather predictions for the different regions in Peru on their web page.