Colombia does not have four seasons. The country sits just north of the Equator, between approximately 4°N and 12°N latitude, where the sun’s position and daily light hours change so little across twelve months that spring, summer, autumn, and winter simply do not form, and the climate system that replaces them operates on a completely different logic: altitude, not calendar, determines what a resident wears every morning.
IDEAM (Instituto de Hidrología, Meteorología y Estudios Ambientales, Colombia’s national meteorology agency) classifies the country’s climate through a system of pisos térmicos (thermal floors), five altitude bands that assign a permanent temperature range to any given city, a range that holds whether it is January or July.
What the thermal floors actually mean for each city
The five thermal floors divide Colombia’s territory by elevation above sea level, and the temperature ranges that correspond to each band. Cities below 1,000 meters, such as Barrancabermeja in Santander at just 74 meters, sit in the warm-to-hot tier and record year-round temperatures between 29°C and 36°C; Bogotá at 2,640 meters stays in the cold tier at 14°C to 18°C daily; and Tunja in Boyacá, at 2,820 meters, holds an annual average of around 12°C with overnight lows that regularly drop below 8°C, regardless of the month.
That altitude-not-calendar reality means a resident of Barrancabermeja does not get a cool respite in December: the city remains oppressively hot throughout the year, with temperatures rarely dropping below 27°C even at night, while a resident of Tunja never benefits from a summer warm-up, since the cold tier at that elevation does not warm meaningfully between seasons. The practical implication for someone relocating to Colombia is that choosing a city is choosing a permanent climate, not a seasonal rotation.
Rainy season means afternoons, not all-day downpours
Colombia does cycle through two rainy seasons and two dry seasons each year: dry periods run from December to March and again from July to August, while rainfall intensifies between April and May and again between October and November. However, residents across Andean cities consistently observe that rainy season rain concentrates in the afternoons, typically between two and five in the afternoon, and lasts one to three hours before clearing, leaving mornings and evenings largely dry.
The distinction matters for daily planning. A newcomer who arrives in Bogotá during the October rainy season and expects continuous grey skies and all-day drizzle, as in northern European winters, will find instead that mornings are clear, afternoons bring heavy showers, and evenings recover, a rhythm that makes rainy season manageable without significantly disrupting outdoor life or travel.
Packing and planning across altitude zones
Colombia’s vertical climate system means that altitude, not calendar logic, governs every practical decision a resident or traveler makes about clothing and preparation. A single trip from Cartagena on the Caribbean coast, where temperatures hover around 32°C with high humidity year-round, to Bogotá or Medellín requires a complete wardrobe shift: light summer clothing for the coast, a jacket and layers for the Andean capitals, and waterproof gear for afternoon rain in both dry and wet seasons.
Worth noting: Medellín sits at 1,495 meters in the temperate tier, holding 22°C to 25°C year-round, earning its reputation as the “City of Eternal Spring,” while Leticia in the Amazon basin, at just 96 meters, maintains a hot and humid 26°C to 30°C with very high year-round rainfall that does not follow the same April-November pattern as the Andean cities.
Climate change adds a layer of variability
To this day, IDEAM tracks an increasing disruption to Colombia’s traditional rainfall cycles driven by El Niño and La Niña events, which extend dry seasons and intensify wet ones beyond their historical ranges, meaning the altitude-not-calendar system remains the structural baseline but the predictability of each rainy and dry period has narrowed over the past two decades, a shift that Colombia’s urban planners and water managers now factor into infrastructure design as a permanent condition rather than an exception.