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 throughout the year without noteworthy rain making Lima one of the driest capitals in the world. The average temperatures range from 12°C/54°F to 18°C/64°F (low) and 24°C/75°F to 28°C/82°F (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).
Weather because of Location
The reason for Lima's unusual weather 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 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
They named the Humboldt Current after Alexander von Humboldt and is one of the major upwelling 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 very low (between 13°C/55°F to 14ºC/57°F in winter and 15°C/59°F to 17ºC/62°F in summer) and swimming is a really "refreshing" experience...
Average Temperatures, Rainfall & Humidity in Lima
The below graphs will give you a good idea about the average temperatures in Lima, the constant high humidity, and the inconsiderable amount of rainfall per year.
Temperatures in Lima
The charts present the values recorded by our weather station as three lines: Highest Temperatures, Average Temperatures and Lowest Temperatures (First chart with values in °F, second chart with values in °C).
Rainfall in Lima
The chart presents the values of the Total Rainfall recorded by our weather station for each month (all values in mm).
Humidity in Lima
The chart presents the values recorded by our weather station as three lines: Highest Relative Humidity, Average Relative Humidity and Lowest Relative Humidity (all values in %).
The Average Temperatures are not directly related to the values for the Lowest and Highest Temperatures, as they only show the most extreme values for each month. The Average Temperatures were calculated by using the measurements from the weather station in intervals of every 15 minutes for the entire month.
The Average Relative Humidity is not directly related to the values for the Lowest and Highest Humidity, as they only show the most extreme values for each month. The Average Relative Humidity was calculated by using the measurements from the weather station in intervals of every 15 minutes for the entire month.
The Seasons in Lima, Peru (Summer & Winter)
The seasons in Lima are easily described, as the city only has two notable distinctive weather conditions: Summer from December to April and winter from May to November.
Summer in Lima
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, normally never too hot, but still humid. Temperatures reach a very pleasant 28°C/82°F by day and 18°C/64°F by night. Unfortunately, already by April summer ends and winter is almost around the corner.
Winter in Lima
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/62°F by day and 11°C/52°F 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 sweater and a pair of thick socks.
Micro-climates, UV Radiation & Climate Changes in Lima
To make the weather and climate for foreigners, a 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.
UV Radiation in Lima
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!
Noticeable Climate Changes in Lima
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 months only three or four month long and there was some sort of spring and autumn with a less cloudy, not as much humidity and much more sun and warmth. In contrast, temperatures in summer hardly ever exceed 30°C/86°F, something that happened in the last few years often. This might not be scientifically proven, but at least worth a thought.