Lima, the capital of Peru, sits on the country's central Pacific coast on a narrow desert plain, backed by the foothills of the Andes, at approximately 12.05°S, 77.04°W. It has an unusual subtropical desert climate (Köppen BWn) — one of the driest of any major city, yet mild, grey and extraordinarily humid — shaped by the cold Humboldt Current offshore, which chills the coast and blankets the city in fog while suppressing almost all rainfall. Being in the Southern Hemisphere, its seasons are reversed relative to the Northern.

Summer, from December to April, is the warm, brighter season, with February the warmest month — average highs around 26–27°C and clearer, sunnier skies that draw people to the coast. Even at its warmest the heat is moderate, tempered by the cool sea, and it rarely becomes uncomfortably hot. This is comfortably the most pleasant time in the city, and the best period for the nearby beaches.

Winter, from June to November, is cool, damp and famously grey, with August and September the coolest — average highs around 18–19°C and lows near 14–15°C. The sky stays blanketed for weeks by a low deck of cloud the locals call the 'panza de burro' (donkey's belly), and a persistent fine mist, the garúa, dampens the streets without ever becoming real rain. High humidity and the lack of sun make it feel colder and gloomier than the mild temperatures suggest.

Lima is astonishingly dry, receiving barely any measurable rain — on the order of just 10–20 mm a year at the coast — which makes it one of the driest capital cities on Earth, second only to places like Cairo. Almost all the moisture comes as the garúa drizzle and fog rather than true rainfall, and the city depends on Andean rivers for its water. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Lima's remarkable climate is the product of the cold Humboldt Current and the Andes: the chilled ocean cools the air near the surface and creates a temperature inversion that traps fog and drizzle but prevents rain, while the mountains block moisture from the Amazon. The result is a fog-shrouded desert metropolis, mild but sunless in winter. The main disruptor is El Niño, which every few years warms the ocean and can, in extreme cases, bring unusual heat and even rare downpours and flooding.

To follow any single measurement in Lima more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.