Map from Google - Colombia

Colombia is a vast country, crossed by the Equator in the southern part, and has different types of climate, although in each of them, there are small variations in temperature throughout the year. The main differences are due to the altitude, which affects the temperature, and to the distribution and amount of rainfall. In fact, there are arid and rainy areas, grasslands and forests, plains where the heat is stifling and plateaus with a mild climate, pristine coastlines with a warm sea and snow-capped peaks in the Andes. In the tierras calientes, from the sea level to about 1,000 metres (3,300 feet) above sea level, it's hot all year round, while the tierras templadas are pleasantly warm, and the tierras frías over 2,000 meters are cool or cold.
Let's see in detail the different climatic zones.


Colombia, arid areas
In the far north, the Guajira Peninsula (see the red circle at the top of the map) is the most arid part of Colombia, in fact precipitation is below 300 mm (12 in) per year, and there is even a desert, called La Guajira Desert. In the north of the peninsula, the Parque Nacional Natural Macuira is a bit greener, because there are some hills that capture a bit of the moisture brought by the trade winds. This offshoot of Colombia, which overlooks the Caribbean Sea, can be affected by hurricanes, in the period from June to November (though most likely between August and October), but this rarely happens, because it is located at the southern end of their trajectory.
In Riohacha, the climate is hot throughout the year: in July and August, lows are around 25 °C (77 °F) and highs around 35 °C (95 °F), while in the coolest months, from December to February, they are just a few degrees lower. Here are the average temperatures.
Average temperatures - Riohacha
RiohachaJanFebMarAprMayJunJulAugSepOctNovDec
RiohachaJFMAMJJASOND
Min (°C)222223242525252524242323
Max (°C)323233333434353533323232
Min (°F)727273757777777775757373
Max (°F)909091919393959591909090

The rains are quite scarce from December to April, then there is a first relatively rainy period in May and June, when 70 mm and 40 mm (2.8 and 1.6 in) of rain fall respectively, a second dry period from July to mid-August, and a second rainy period between September and mid-November; October is the wettest month with 150 mm (6 in) of rain. Here is the average precipitation.
Average precipitation - Riohacha
RiohachaJanFebMarAprMayJunJulAugSepOctNovDecYear
RiohachaJFMAMJJASONDY
Prec. (mm)42325704015401301506020553
Prec.(in)0.20.10.112.81.60.61.65.15.92.40.821.8
Days111373249116250

Considering both the heat and the rains, here the best time is from December to March.
Although Riohacha experiences little rainfall, with a total amount of 550 mm (21.5 in) per year, this rainfall pattern with two dry and two rainy periods, is also found in other less arid areas: in fact it is typical of the sub-equatorial climate, where the sun is directly overhead twice in the year.
The Caribbean Sea is warm all year round throughout the Colombian coast, therefore also in this part of the coast, as can be seen in the following table.
Sea temperature - Riohacha
RiohachaJanFebMarAprMayJunJulAugSepOctNovDec
RiohachaJFMAMJJASOND
Sea (°C)262626262727272828292827
Sea (°F)797979798181818282848281

In the south-western inland areas, between the two Andean mountain ranges and near the town of Villavieja, there is another arid zone, the Tatacoa Desert (see the small circle at the bottom of the map). It is an area with canyons and rocky landscapes, whose good visibility allows to see shooting stars in the periods of meteor showers, but also the stars in the astronomical observatory and a collection of fossils of the area in the archaeological museum. The average altitude is about 400 metres (1,300 feet). The heat is intense throughout the year, as we can see from the temperature of the nearby town of San Alfonso.
Average temperatures - San Alfonso
San AlfonsoJanFebMarAprMayJunJulAugSepOctNovDec
San AlfonsoJFMAMJJASOND
Min (°C)232323232223232323232222
Max (°C)343434333435353636343233
Min (°F)737373737273737373737272
Max (°F)939393919395959797939091

During the day, temperatures can reach 40 °C (104 °F) all year round, while at night they can drop to around 15/17 °C (59/63 °F).
The rains are below 1,000 mm (40 in) per year, but they are not entirely absent: some showers can occur throughout the year, but mainly in March and April and from October to December, while the driest months are June, July and August.


Colombia, climate of the savanna
The climate of the savanna is hot year-round, with a dry season and a rainy season. South of the Guajira Peninsula, along the coast of the Caribbean Sea, the climate becomes more humid, the heat is tropical rather than torrid, and the rains become more abundant. In Barranquilla, highs range between 31 °C and 33 °C (88 and 91 °F) throughout the year, and lows between 23 °C and 25 °C (73 to 77 °F).
Here are the average temperatures.
Average temperatures - Barranquilla
BarranquillaJanFebMarAprMayJunJulAugSepOctNovDec
BarranquillaJFMAMJJASOND
Min (°C)232424252525252524242424
Max (°C)313232333333333333323232
Min (°F)737575777777777775757575
Max (°F)889090919191919191909090

Here it almost never rains from mid-December to April, but then the rainy season, from May to mid-November, is more pronounced, with a peak in the last part (Semptember-October). The summer break is not so evident: in July, 65 mm (2.6 in) of rain fall anyway. The total annual rainfall is 815 mm (32 in). Here is the average precipitation.
Average precipitation - Barranquilla
BarranquillaJanFebMarAprMayJunJulAugSepOctNovDecYear
BarranquillaJFMAMJJASONDY
Prec. (mm)1011512085651101501657525813
Prec.(in)0000.64.73.32.64.35.96.53132
Days00049971013158277

In Cartagena, a little more to the south, the rainfall reaches 920 mm (36 in) per year, with no rain from December to March, 80 mm (3.2 in) in July and a peak of 220 mm (8.5 in) in October.
The best time to visit Barranquilla and Cartagena, goes from December to April.

Further south, the rainfall exceeds 1,000 mm (40 in) per year, the summer break almost disappears, and the rainy season starts earlier, ie in April. In Montería, the best time is from December to March.

In the inland areas located east of the coast, the climate is similar to that of this portion of the coast, with a greater risk of intense heat, around 37/40 °C (99/104 °F) on sunny days.

Even to the east of the Andes (in the map, the area to the right), there is a large area which has a similar climate, hot throughout the year, with a dry and a wet season: this is the area of the so-called Llanos, plains and hills occupied by the savannah. Compared with the previous area, here the rainfall is more abundant, above 2,000 mm (79 in), but there is still a relatively dry season, from December to March in the north (see Arauca), and from mid-December to February in the centre and south (see Las Gaviotas, San José del Guaviare). The dry period is also the hottest, with peaks above 35 °C (95 °F), even though air humidity is lower than in the rainy period.

The small Caribbean islands of San Andrés and Providencia, to the east of Nicaragua, are hot all year round, with highs around 29/30 °C (84/86 °F), and very rainy: the total rainfall is 1,900 mm (75 in) per year; we put them in this section because here too there is a dry season, from mid-January to April, which therefore is the best, and a rainy season from May to mid-January.
Here is the average precipitation in San Andrés.
Average precipitation - San Andrés
San AndrésJanFebMarAprMayJunJulAugSepOctNovDecYear
San AndrésJFMAMJJASONDY
Prec. (mm)754025351302052002002403252751401885
Prec.(in)31.611.45.18.17.97.99.412.810.85.574.2
Days86451118222020212015170


Colombia, areas with an equatorial climate
There are two areas of Colombia in the west and south-east, which have an equatorial climate, hot and rainy throughout the year. The rains in tropical areas generally occur in the form of downpour or thunderstorm, preferably in the afternoon or in the evening.
In the southern part of the coast of the Caribbean Sea, in the Córdoba Department, north of the border with Panama, more than 3,000 millimetres (120 inches) of rain per year fall. The only period in which precipitation drops to less than 150 millimetres (6 inches) per month, although it remains above 100 mm (4 in), is from January to March, which therefore is the best period in this area.
South of the border with Panama, the coastal area of the Pacific Ocean also receives heavy rainfall throughout the year. East of the coast, on the slopes at the foot of the Western Cordillera of the Andes, we find the rainiest city in Colombia, as well as one of the rainiest in the world: Quibdo, where rainfall reaches as high as 8,000 mm, ie 8 metres (or 26 feet)! Here you can see heavy downpours almost daily, and also the cloudiness that forms in late morning and persists in the afternoon, however if you want to venture into this region you can choose February and March when it rains "only" 22 days per month, with "only" 520 millimetres (20.5 in) of rain per month... otherwise if you're looking for strong emotions, you can choose August, when 840 mm (33 in) of rain fall, it practically rains in a single month like it does in an average rainy city in an entire year. In fact, Quibdo is the rainiest city of a certain size in the world (in some mountainous areas of India, where it rains even more, there are only villages and small towns).
Here is the average precipitation.
Average precipitation - Quibdo
QuibdoJanFebMarAprMayJunJulAugSepOctNovDecYear
QuibdoJFMAMJJASONDY
Prec. (mm)5555155256607207558158406806407205808005
Prec.(in)21.920.320.72628.329.732.133.126.825.228.322.8315.2
Days242222252726262727272626305

The temperatures are high throughout the year, and the air is constantly moist. Here are the average temperatures.
Average temperatures - Quibdo
QuibdoJanFebMarAprMayJunJulAugSepOctNovDec
QuibdoJFMAMJJASOND
Min (°C)232323232323232323232323
Max (°C)303030313132313131303030
Min (°F)737373737373737373737373
Max (°F)868686888890888888868686

Further south, near the border with Ecuador (see San Andrés de Tumaco), the situation is a bit better, because from July to mid-December, and especially from October to mid-December, it rains on average every second day, and from 100 to 200 millimetres (4 to 8 in) per month fall: still better than the rest of the year.

The climate of Colombia is influenced by the phenomenon known as ENSO: a cycle that sees periods in which the waters of the Pacific become warmer than normal, those of El Niño, alternating with normal periods, and others in which they are colder than normal, those of La Niña. In much of Colombia, in the years of El Niño the rainy season becomes more hotter and drier than normal, while in the years of La Niña it becomes cooler and rainier. On the contrary, in the southernmost part of the coast, north of Ecuador, the relatively dry season that normally occurs from October to December, does not occur in the years of El Niño, so that the rains are still heavy, like in the rest of the year, while in the years of La Niña it becomes more pronounced, therefore definitely dry.

The area we are dealing with (that is, the one circled in the left on the map), is not the only part of the country with an equatorial climate. The south-eastern part of Colombia, that of the Amazon rainforest (in the map, the area highlighted on the right), has a similar climate. This is an area, however vast, sparsely populated and difficult to penetrate. In the far south, in Leticia, in the area where the Amazon River marks for a few kilometres the border with Peru, it rains a lot throughout the year, with a slight decrease in July and August.
Here is the average precipitation.
Average precipitation - Leticia
LeticiaJanFebMarAprMayJunJulAugSepOctNovDecYear
LeticiaJFMAMJJASONDY
Prec. (mm)3553353503502902051601702352653002903305
Prec.(in)1413.213.813.811.48.16.36.79.310.411.811.4130.1
Days242122222319161617192123243

In fact, since here we are, albeit slightly, south of the Equator, the seasons are reversed, so that June, July and August can be considered as winter months, and sometimes nights can be a bit cool from June to September. Here are the average temperatures.
Average temperatures - Leticia
LeticiaJanFebMarAprMayJunJulAugSepOctNovDec
LeticiaJFMAMJJASOND
Min (°C)232323232322212122222223
Max (°C)313131303029303131313131
Min (°F)737373737372707072727273
Max (°F)888888868684868888888888



Colombia, climate of the Andes
In the west, Colombia is crossed from north to south by the Andes, which are divided into three mountain ranges, called Cordilleras: Western, Central and Eastern, to which must be added the Sierra Nevada de Santa Marta, which is located in the north and is isolated from the Cordilleras, and is home to the highest peak of Colombia, Pico Cristóbal Colón (Christopher Columbus) with its 5,775 metres (18,947 feet). However, there are several peaks (often volcanic) exceeding 5,000 metres (16,500 ft). Considering that we are at the Equator, to find very low temperatures we must rise above 3,500 metres (11,500 ft), which is typically the limit beyond which there are neither trees nor towns. Between 3,500 and 4,500 metres (11,500 and 15,000 ft) there are areas with a particular kind of vegetation, a tropical high mountain tundra with shrubs and cactuses, called páramos, while over 4,500 metres (15,000 ft) there are snow-covered areas (called nevados).
In the Andean zone, the rainfall is more or less abundant depending on slope exposure, while the temperature varies with altitude.

In the valleys between mountain ranges, the rainfall amount is lower than in the two external sides, typically between 900 and 1,200 mm (35 and 47 in) per year. We have seen that the western side, which overlooks the Pacific Ocean, is rain-soaked, but so is the eastern side, even though it doesn't reach the peaks of Quibdo. For example, in Villavicencio, at 430 metres (1,400 feet) above sea level, almost 4,000 mm (157 in) of rain per year fall, and the only months in which precipitation goes below 100 mm (4 in), are January (40 mm or 1.6 in) and February (90 mm or 3.5 in). Here, the best time goes from mid-December to mid-March. Further south, in Florencia, the least rainy period, with rainfall between 100 and 150 mm (4 and 6 in) per month, is shorter, and it's limited to December and January.

Bogotá

In the interior area of the Andes, there are many cities located at high altitudes. The capital Bogotá is located at 2,600 metres (8,500 ft), and has a cool, spring-like climate all year round, with maximum temperatures ranging between 17 and 19 °C (63 and 66 °F), and minimum temperatures from 6 to 8 °C (43 to 46 °F). From November to March, in the open country there may be slight frosts at night, while within the city, the night temperature is a few degrees higher, because of the urban heat island effect. In the daytime, the temperature rarely exceeds 22 °C (72 °F), so the air is mild, but the equatorial sun's rays at this altitude are very strong, even though the sky is often cloudy. When the sun shines, if you are in the sun it feels warm, but if you go in the shade you realize that the air is cool. However, the highest temperature ever measured is 30 °C (86 °F), recorded in April. Here are the average temperatures.
Average temperatures - Bogotá
BogotáJanFebMarAprMayJunJulAugSepOctNovDec
BogotáJFMAMJJASOND
Min (°C)678888877887
Max (°C)181819181817171718181818
Min (°F)434546464646464545464645
Max (°F)646466646463636364646464

Rainfall totals 940 mm (37 in) per annum; the rainfall pattern is related to the two zenith passages of the sun, and therefore sees two maxima in April-May and October-November, and two minima from December to February and from June to September. However, the summer minimum is not very reliable, so much so that the rains decrease in quantity (only 45 mm or 1.8 inches in July, and 40 mm or 1.6 inches in August) but not in frequency (it rains often anyway). Besides, at this time the sky is often cloudy. Therefore, January and February are the best months to visit the Colombian capital, even though it rains about 7 times per month and there are just 5/6 hours of sunshine per day, because it's better than in the rest of the year, while October and November are the worst ones, because they are the wettest months.
Here is the average precipitation.
Average precipitation - Bogotá
BogotáJanFebMarAprMayJunJulAugSepOctNovDecYear
BogotáJFMAMJJASONDY
Prec. (mm)5050701001055545405514514085940
Prec.(in)222.83.94.12.21.81.62.25.75.53.337
Days7710171716161312181512160

A few kilometres west of Bogotá, near Mondoñedo, there is a small arid zone, called a bit emphatically "Sabrinsky desert", where rainfall drops below 500 mm (20 in) per year. Rainfall drop below 500 mm (20 in) also to the north-east of the city, and about 100 km (60 mi) to the north-east, in the department of Boyacá, we find the "Candelaria Desert", an arid area at about 2,100/2,500 metres (6,900/8,200 feet) above sea level, where therefore the temperatures are mild, similar to those of the capital.

The city of Cali is located at a lower altitude, around 1,000 metres (3,300 feet), and its temperature is definitely higher than that of Bogotá, so that the climate is hot, but all in all it's usually bearable, at least more than in the plains; however, sometimes the temperature can reach 35 °C (95 °F) all year round. Here are the average temperatures.
Average temperatures - Cali
CaliJanFebMarAprMayJunJulAugSepOctNovDec
CaliJFMAMJJASOND
Min (°C)191919191919181919191919
Max (°C)303030302930303130292929
Min (°F)666666666666646666666666
Max (°F)868686868486868886848484

In Cali, both the amount of rainfall (about 1,000 mm or 40 inches) and the pattern, are similar to those of Bogotá, although the amount of sunshine is higher and the summer rains are less frequent, so here the summer dry season, from June to August, is also a good period. In the western districts of the city, closer to the mountains, and especially in the south-west, closer to the Farallones de Cali, a massif of 4,000 metres (13,100 ft), the rains are more abundant, as you can see from the average precipitation recorded at the university.
Average precipitation - Cali
CaliJanFebMarAprMayJunJulAugSepOctNovDecYear
CaliJFMAMJJASONDY
Prec. (mm)901201451901659055651101701601301485
Prec.(in)3.54.75.77.56.53.52.22.64.36.76.35.158.5
Days1113151817129913191713166

Compared with Bogotá and Cali, Medellín is located at an intermediate altitude, 1,500 metres (5,000 feet), and as can be expected it has warm daytime temperatures, but without excesses, with cool nights: lows are around 14/16 °C (57/61 °F), while highs are around 27/29 °C (81/84 °F). Here are the average temperatures.
Average temperatures - Medellín
MedellínJanFebMarAprMayJunJulAugSepOctNovDec
MedellínJFMAMJJASOND
Min (°C)141515161615151515151515
Max (°C)282829282828292828272727
Min (°F)575959616159595959595959
Max (°F)828284828282848282818181

The rains, however, are more abundant, about 1,500 mm (60 in) per year, and there is no decrease in summer, so the best time here goes from December to February, being the only relatively dry period.
Here is the average precipitation.
Average precipitation - Medellín
MedellínJanFebMarAprMayJunJulAugSepOctNovDecYear
MedellínJFMAMJJASONDY
Prec. (mm)6580125160200160120150180210145951685
Prec.(in)2.63.14.96.37.96.34.75.97.18.35.73.766.3
Days121317222319171922242115224

Another city that lies at a high altitude is Popayán, about 2,000 metres (6,500 feet) above sea level, therefore at an intermediate altitude between Bogotá and Medellin. This is really a city of eternal spring: highs are around 24/25 °C (75/77 °F), and lows around 12/14 °C all year round. Here are the average temperatures.
Average temperatures - Popayán
PopayánJanFebMarAprMayJunJulAugSepOctNovDec
PopayánJFMAMJJASOND
Min (°C)131314141413121212141414
Max (°C)242425242525252525242424
Min (°F)555557575755545454575757
Max (°F)757577757777777777757575

Here, however, the rains are more abundant, about 1,900 mm (75 in) per year, and being situated more to the south, it doesn't experience a real decrease in winter (in fact, it rains a lot even in January and February), so here the best time goes from mid-June to mid-September. Here is the average precipitation.
Average precipitation - Popayán
PopayánJanFebMarAprMayJunJulAugSepOctNovDecYear
PopayánJFMAMJJASONDY
Prec. (mm)1501451701851401004030902653102851910
Prec.(in)5.95.76.77.35.53.91.61.23.510.412.211.275.2
Days17151720181610711222422199

When to go

It's hard to find a period that works for all of Colombia, but in most of the country the best time is from December to March, because it is the driest, or at least the least rainy.
However, there are areas where the rains are abundant throughout the year (see the forest), or where the least rainy season is inverted (see the extreme south both of the Amazon and of the Andean area), or areas where the least rainy period runs from August to November (the southernmost part of the Pacific coast, moreover affected by the El Niño cycle).
As we have seen, for swimming and sun bathing, the Caribbean Sea is warm all year round. The Pacific Ocean is warm all year round as well, and has more constant temperatures: 25/26 °C (77/79 °F) for most of the year, with a peak of 27 °C (81 °F) in October, but as we said this coastline is rainy all year round.

What to pack

On plains and lowlands, in general, light clothing all year round. In the forest, loose fitting clothing, light shirts and pants of natural fibres (cotton, linen) or synthetics that breathe, maybe with long sleeves for mosquitoes; possibly a light sweatshirt and a light raincoat for thunderstorms. On the coast, possibly a light scarf and a light sweatshirt for the sea breeze. In the savannah (Barranquilla, Cartagena), you can bring a light sweatshirt and a light raincoat for thunderstorms, during the rainy season.
In the tierras templadas (see Medellín), light clothing, a sweatshirt for the evening, raincoat or umbrella.
In the tierras frías (see Bogota), clothes for spring and autumn, sweater or sweatshirt, jacket, raincoat or umbrella.
On high mountains, warm clothes, down jacket, hat, gloves, scarf, hiking shoes.