Guayaquil, Ecuador's largest city and principal port, sits on the Guayas River near the Pacific coast in the west of the country, on a low, hot coastal plain at approximately -2.17°S, 79.92°W. Though almost on the equator, the cool Humboldt Current offshore suppresses rainfall for much of the year, giving it a tropical savanna climate (Köppen Aw) — hot and humid, with a sharply defined wet and dry season.

The wet season, from January to April — the local summer — is hot, very humid and rainy, with highs around 31–32°C and warm, sticky nights. Heavy afternoon downpours and thunderstorms bring nearly all of the year's rain, and the humidity can feel oppressive on the low river plain, with flooding a recurring risk during the heaviest rains.

The dry season, from May to December — the local winter — is warm, drier and often overcast, with highs around 29–30°C and slightly cooler, more comfortable nights. Skies are frequently grey with low cloud rolling off the cool Humboldt Current, but rain is scarce for months, making this drier, milder stretch the more comfortable time of year.

Guayaquil receives on the order of 1,000–1,100 mm of rain a year, overwhelmingly concentrated in the wet season from January to April — February and March are the wettest — while from June to November it is nearly rainless; the cool offshore current is the reason totals stay so modest for the equatorial latitude. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Guayaquil's climate is governed by the cool Humboldt Current, which suppresses rainfall and keeps the dry season grey and cloudy despite the equatorial sun. In El Niño years, when that current weakens and the ocean warms, the pattern reverses dramatically: rainfall can multiply many times over, bringing severe, prolonged flooding to the low-lying coastal plain — the city's most serious weather hazard.

To follow any single measurement in Guayaquil 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.