Arequipa and Colca Canyon Climate
The climate of Arequipa is one that is especially warm and rather dry, all through the year. Arequipa lies on the border of the southernmost tip of Peru's Desert Coast and the Andes and hence enjoys plenty of, sometimes strong sun with daytime temperatures rarely falling under 20°C.
At night however temperatures in Arequipa can drop sharply, particularly in June, July and August, when evening temperatures hover around 10°C and winds can pick up making it feel quite chilly.
Rain is something hardly seen in Arequipa outside of the rainy season. Even in the rainy season from December to March, with its high point in February, the rain does not fall like in some of the other Andean cities such as Puno and Cusco. Arequipa is a city having an almost spring like climate all year round.
The Colca Canyon is more prone to the climate grills of the high Andean Mountains. Located somewhat higher than Arequipa and surrounded by snowcapped mountains, this region gives you more the feeling of the Andean highlands, and for a reason. Being surrounded by large “Altiplanos” Andean flat highlands, temperatures in this region do fluctuate a lot. In general there are two seasons in this as in most Andean regions; the Dry and the Wet season. The wet season starts around December and ends around March. The dry season makes up the rest of the year. In the transition periods (November & April) rain can still fall but the days will start to brighten up until they are with clear blue skies all day long. The sun is due to the altitude a factor to keep in mind as the solar radiation is very strong in this region. This makes day temperatures in these months quite warm at times.
When the sun goes down, and mind you this can be very soon as you are in a steep canyon, the temperatures go down significantly. In the months June, July and August temperatures at night well below freezing are frequent. In the morning it takes a couple of hours to warm up again but once the sun breaks through, the canyon will quickly warm up before cooling down at night again.