Ecuador lies directly on the equator, so the entire country enjoys 12 hours of direct equatorial daylight 365 days a year. However, the climate you will experience depends largely on where you are in Ecuador, since there are four distinct geographical areas—the Sierra (mountains), the Oriente (eastern rainforests), the La Costa (Pacific coastal plains), and the Galapagos Islands.
Andes
In general you could say that the Andes knows two seasons, the rainy season which starts around December and lasts till May, and the dry season with more cloudy and sunny weather. In the Andes the temperatures are quite consistent all year round with during the day an average of 21°C but the nights can be a bit colder and temperatures can drop to an average of 10°C.
However, the temperatures are about the only thing that is consistent about the weather of the Andes, especially in Quito is the weather is very unpredictable. This is mainly due to its location and altitude. At 2800 meter above sea level and surrounded by mountains, the weather in the city can change very quickly. It is not uncommon to experience different types of weather throughout the day. You could for example start your day wearing a nice warm sweater because it is so cloudy and during the day get your T-shirt and shorts out because the hot equatorial sun will be shining brightly down on you. But don´t be fooled because heavy rain can appear out of nowhere. So it is very recommendable to pack a umbrella and to wear layers when exploring the city.
Amazon
The weather in the Amazon is also quite unpredictable and it can be difficult to give a clear indication of as it can not only vary per day but also per month and year. However, as the name “Rainforest” already implies, rain is a consistent factor in the jungle. Though men also speaks of a dry and a wet season in the Rainforest, has this more to do with the amount of rain that falls in those months than with the lack of rain. The dry season only means that there is a decline in the rainfall and it will usually only rain for part of the day. The so called wet season last from March till June. One of the advantages of traveling to the jungle during this season is that more of the jungle can be explored by canoe as the high rivers makes more parts of the jungle accessible.
In the “dry” season which runs from September until May a decline in the rainfall is noticeable as well as a peak in the temperatures. On average the temperature in the amazon is 25°C all year round but during these months they can rise till 40°C during the day. Every year around February it gets very dry and It is also that during this time of the year the Laguna Grande can run partially dry. Giving the Amazon a completely different appearance. Nevertheless, is a trip to the jungle during this season is also well worth it, as the receding water brings animals to the surface that usually avoid the beaten-track.
But either way, whether you are traveling to the jungle in the dry or the wet season always be sure to pack your rain jacket, you will need it.
Coast
If like me, you enjoy lying on the beach and soaking up the sun you will certainly enjoy the tropical climate of the coast, with average temperatures from 26°C in the north and 23°C in the south. The best time to visit the Ecuadorian coast is strangely enough in the rainy season which runs from December till April. Don´t worry though, it won´t rain all day long, usually the rain occurs during the afternoon and in the evening. The warmest months are February, March and April. However, during the dry season it can get much cooler, muggier and the clear blue skies make way for darker clouds.
Galapagos
When it comes to the Galapagos Island, there is never a bad time to visit them. The changes that occur in the sub-tropical climate of the Galapagos come with the changes in the ocean currents. From the December till May warms the El Niño current both land and water and days are filled with a mixture of warm and sunny weather along with rain in the afternoon. The average temperatures during this period are 27°C to 32°C.
The cool season is caused by the Humboldt current which brings cooler air to the Galapagos Islands, cloudier skies and a decline in the rain fall. The water is also a lot cooler during this period which makes it more suitable for diving and you will have a better chance at observing the Galapagos´ famous marine life. The average temperatures during this period are 21°C to 27°C