As the name suggests, Ecuador is bisected (in the north) by the Equator, the imaginary line that divides the Earth, and in which the days last 12 hours throughout the year. One would expect, therefore, an equatorial climate, hot and humid with year-round rains, but this is only true for the eastern part of the country and the northernmost part of the coast, both covered by forests. The central part is in fact crossed by the Andes and is therefore more or less cold depending on altitude, while almost the entire western plain and coast, is affected by a cool ocean current, which lowers a bit the temperature and makes the climate more arid.

The forest



Ecuador, equatorial climate
In the northernmost part of the coast, we find a small area occupied by forests and mangroves, where the climate is hot and humid all year round; in Valdez, near the border with Colombia, 2,400 millimetres (95 inches) of rain per year fall.
Across the vast Amazon area to the east, the climate is equatorial as well, ie hot and humid all year round. The amount of rainfall is quite remarkable, around 2,800/3,000 millimetres (110/118 inches) per year in most of the plains. The rains occur primarily in the form of heavy showers or thunderstorms in the afternoon. The (relatively) less rainy period goes from August to November in the north-west, while in the Amazon it goes from November to March, when, however, from 150 to 200 mm (6 to 8 in) of rain per month fall. The average temperature ranges from 26 °C (79 °F) in the Southern Hemisphere's summer (December-January), to 23 °C (73 °F) in winter (with July as the coolest month). Relative humidity is constantly high and makes the heat sweltering.
In the central area of the country, along the eastern slopes of the Andes, we find the rainiest part of the country.

Puyo

In the city of Puyo, at almost 1,000 metres (3,300 feet) above sea level, therefore at the boundary between the tierras calientes and the tierras templadas, 4,300 millimetres (170 inches) of rain per year fall, and it rains almost every day. Here is the average precipitation.
Puyo - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)3002953904553253903403453553603653704290
Prec.(in)11,811,615,417,912,815,413,413,61414,214,414,6168,9
Days211922232222222121232121258

The only consolation is that the altitude makes the temperatures pleasant, around 20 °C (68 °F) as daily average all year round. Here it doesn't really make sense to speak of "best time", however, January and February are the only months in which rainfall amounts to "only" 300 mm (12 in) per month.
Here are the average temperatures of Puyo.
Puyo - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)171717171716161616161717
Max (°C)262626262625252627272727
Min (°F)636363636361616161616363
Max (°F)797979797977777981818181

In Puyo, sunshine is scarce, because the sky is often cloudy.
Puyo - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours322233334443

In the whole east of the country, in the vast area occupied by the Amazon forest, the altitude drops to 200/300 metres (600/1,000 feet), so there's an intense and muggy heat all year round.

The plain



Ecuador, climate of the west
West of the Andes we find a plain, which has a tropical climate, with a dry season (which goes from July to November in the north, and from May to December in the south), and a wet season (December to June in the north, January to April in the south), although the rainfall varies greatly: in general, the coasts are drier than the areas at the foothills of the Andes, and the north receives more rainfall than the south.

In the northern part of the coast (see Esmeraldas, Atacames), it is hot all year round.

Esmeraldas

Here are the average temperatures in Esmeraldas.
Esmeraldas - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)222323232322222221222222
Max (°C)292930302929282828282828
Min (°F)727373737372727270727272
Max (°F)848486868484828282828282

In this area of the coast, some rains, in the form of showers or thunderstorms, can occur throughout the year, even though rains of some importance, and sometimes abundant, occur only in the first months of the year.
Esmeraldas - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)1802001851451101055035454530551185
Prec.(in)7,17,97,35,74,34,121,41,81,81,22,246,7
Days1616141413141199868138

In Esmeraldas and Atacames, the sun is rarely seen all year round; above all, it is rare for it to shine intensely, since it is often veiled by mist or a cloudy layer; paradoxically, this happens more often in the drier period. Here are the sunshine hours in Esmeraldas.
Esmeraldas - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours334433332222

The sea in the northern part of the coast is warm all year round.
Esmeraldas - Sea temperature
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Temp (°C)262726272727262626262626
Temp (°F)798179818181797979797979

Manta

In the central part of the coast, the temperature is still high throughout the year, however, it decreases slightly in the austral winter and in spring, as we can see from the temperature of Manta.
Manta - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)222322222221202020202021
Max (°C)303030303029282828282829
Min (°F)727372727270686868686870
Max (°F)868686868684828282828284

Already in the central part of the coast, the cool sea current inhibits the formation of clouds able to generate rains, for many months a year: in Bahia de Caraquez, rainfall amounts to 500 mm (20 in), and in Manta to only 250 mm (10 in). Here is the average rainfall in Manta.
Manta - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)4095702535511135254
Prec.(in)1,63,72,810,10,20,20000,10,210
Days57641110001127

However, the sunshine amount is low here as well, because the sky is often cloudy, and fogs and mists often form, especially in the dry period.
Manta - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours445543333333

In the central part of the coast the sea is warm all year round, however, it is a little warmer in the first months of the year.
Manta - Sea temperature
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Temp (°C)262727262726262525252526
Temp (°F)798181798179797777777779

Santa Elena

In the southern part of the coast, in the province of Santa Elena (see Santa Elena, Salinas, La Libertad, General Villamil Playas), there is a peninsula in which even a desert is found, in fact rainfall is lower than 150 mm (6 in) per year, and is concentrated in the period from January to April, which, however, is when tourists frequent the beaches, also because the sea is warmer.

Salinas

Salinas is the westernmost city in Ecuador, and is located at the tip of the Santa Elena Peninsula. Here are the average temperatures: as you can see, from June to November the temperature becomes quite cool.
Salinas - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)222323222120191919192021
Max (°C)282930292826242424242527
Min (°F)727373727068666666666870
Max (°F)828486848279757575757781

Even though generally the rains are very scarce also in the rainy period, in the years of El Niño there can be heavy rains, moreover, the sea can rise, and during high tide, anomalous waves can cause coastal flooding.
Here is the average precipitation in Salinas.
Salinas - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)1525601510000001125
Prec.(in)0,612,40,6000000004,9
Days46740000000021

In addition, in this period, although it's the warmest of year, sunshine is not so frequent, because there is often a haze that covers the sun. In the period from June to November, the heat is less intense, indeed it is almost cool to go to the beach, and it never rains. It must be said that the amount of sunshine is not very good even in this period, actually it is even worse. Here are the sunshine hours in Salinas.
Salinas - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours456664444455

In the southern part of the coast, the sea becomes a little cool from July to November, as you can see in the following table, regarding the sea temperature at Playas.
Playas - Sea temperature
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Temp (°C)242625242423222121222223
Temp (°F)757977757573727070727273

As you move away from the coast, the rains increase, reaching the highest levels at the foot of the Andes. From south to north, precipitation ranges from 1,000 mm (40 in) per year in Guayaquil, to 2,000 mm (79 in) in Montoya, to 2,800 mm (110 in) in Santo Domingo de los Colorados, where it rains a lot from February to April, and it still rains a lot in June: here the driest months are definitely July and August, with less than 40 mm (1.6 in) per month, anyway, from July to November, rainfall drops below 70 mm (2.8 in) per month.
Here is the average rainfall of Guayaquil, in the south central part, a short distance from the coast.
Guayaquil - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)2302402501506035101236351026
Prec.(in)9,19,49,85,92,41,40,400,10,10,21,440,4
Days182020146210011487

The Andes



Ecuador, climate of the Andes
The central part of Ecuador is crossed by the Andes, which are divided into two mountain ranges, and include several volcanoes of considerable height. Glaciers start at a height of about 5,000 metres (16,500 ft). In the Cordillera Occidental lies the volcano Chimborazo, the highest peak of the country with its 6,268 metres (20,564 feet), while in the Cordillera Real we find Cotopaxi, 5,897 metres (19,347 ft), Antisana, 5,704 metres (18,714 ft) and Cayambe, 5,790 metres (18,996 ft).

Cotopaxi

Quito

Between the mountain ranges there are plateaus, in which we find important cities, such as the capital Quito, which is the second highest capital in the world, being located at 2,850 metres (9,350 ft) above sea level. Here the temperatures are mild, spring-like throughout the year: highs are around 19/20 °C (66/68 °F), although some days can be a bit warmer, and lows are around 9/10 °C (48/50 °F), although sometimes at night the temperature can approach the freezing point.
Quito - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)101010101099999910
Max (°C)191919192019202021202019
Min (°F)505050505048484848484850
Max (°F)666666666866686870686866

The rainfall amounts to 1,200 mm (47 in) per year, and is frequent and abundant from October to May. Therefore, the best time here goes from June to mid-September, but in reality the only months where it rarely rains are July and August. Here is the average precipitation.
Quito - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)12013015518513055202580135951051235
Prec.(in)4,75,16,17,35,12,20,813,15,33,74,148,6
Days13141719169449161212145

In the capital, the amount of sunshine throughout the year is not high, however, it is slightly better in the dry period.
Quito - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours655456766656

At higher altitudes, the temperature decreases further. At 3,500 metres (11,500 ft), the daily average temperature is around 7/8 °C (45/46 °F) throughout the year, this means that it's cold, and at night it can freeze.
There are other cities that are located at high altitudes in the Andes, but are drier than the capital. For example in Cuenca, in the south, rainfall totals 710 mm (28 in) per year, while it drops to 625 mm (24.5 in) in Ibarra, located in the north.
Along the western slopes of the Andes, even at low altitudes, the sky is often overcast during the cooler and drier season (July-December).

El Niño



As already mentioned, the climate of Ecuador is affected by a cycle in which normal periods alternate with those of El Niño and La Niña. During the years of "El Niño", the sea level rises by about 2/3 centimetres (1 inch), the water (and air) temperature rises by a few degrees, and heavy rains affect the coastal zones, in the period from December to May, with possible floods. The Andean areas receive more rainfall than usual as well. On the contrary, during the years of "La Niña", the temperature of the sea (and of the air) becomes cooler than normal, and rainfall more scarce.

When to go



Wanting to find a single period which is best to visit Ecuador, we can choose the Southern Hemisphere's winter, and in particular the months of July and August, which are the least rainy, and in some areas also the sunniest. It must be said, however, that in the areas of the forest it rains a lot even in this period, and the amount of sunshine is low. On the other hand, along the west coast, although it rarely rains, the sky is often cloudy.

What to pack



For the Amazon, in the plain, loose fitting, lightweight clothing of natural fibres, maybe with long sleeves for mosquitoes; possibly a light sweatshirt and a light raincoat for thunderstorms. For the Amazon at low-mountain altitudes (see Puyo), light clothes, sweatshirt and light jacket for the evening, raincoat.
For the western plains and the coast: light clothing, raincoat and lightweight sweatshirt in the rainy season (December to June in the north, January to April in the south), sweatshirt for the evening in the cooler season (June to September).
For the southernmost part of the coast, throughout the year, a sweatshirt for the evening; from June to September, a sweater or sweatshirt, a light jacket.
For Quito and the Andes, clothes for spring and autumn, sweatshirt or sweater, warm jacket for the evening, sun hat; raincoat or umbrella especially from October to May.
For the highest mountains, warm clothes, down jacket, hat, gloves, scarf.



See also the climate of the Galápagos.