Medellín weather, month by month, and when to come

The pattern: two dry seasons, two wet

Medellín is at 1,495 meters, six degrees north of the equator. The altitude cancels the latitude and the result is a year with almost no temperature change: daytime highs in the high 70s to low 80s Fahrenheit (about 26–28°C), overnight lows in the low-to-mid 60s (about 16–18°C), every month. No frost, no heat wave. Nobody's apartment has heating, and very few have air conditioning, because neither is needed.

What does change is rain. The equatorial rain belt passes over the valley twice a year, which gives Medellín a bimodal pattern: dry from December to February, wet in April and May, a second, shorter dry spell in July and August, and the wettest stretch of all in September to November. Even in the wet months, rain here usually means a clear morning, a build-up of cloud after lunch, and a hard storm in the late afternoon or evening that passes in an hour or two. Days of continuous grey drizzle are rare. Humidity is moderate, not tropical-coastal.

The other seasonal variable is air. The valley traps pollution, and the transition periods, roughly late February into March and again October into November, are when the city typically issues air-quality alerts. If you have a respiratory condition, that matters more than the rain.

Month by month

Month	Rain	Air	Notes for a visitor
December	Dry	Good	Alumbrados, the city's famous Christmas lights along the river, run all month. Colombians travel and the city fills up; furnished rents peak. Book early.
January	Driest month	Good	The best weather of the year. Sunny, breezy, warm days, cool nights. The first two weeks are still holiday season; after mid-month the city settles down.
February	Dry, turning	Deteriorates late	Still mostly dry. Air-quality episodes often begin late in the month. The best value month: good weather, post-holiday prices.
March	Rain returns	Often poor	Afternoon storms start. The air-quality alert season peaks. A fine month if your lungs are healthy; the month to avoid if they're not.
April	Wet	Improves	The first rainy season proper. Mornings are still usable; plan indoor afternoons. Holy Week (Semana Santa) brings a holiday rush.
May	Wettest of the first season	Good	Rain most afternoons. The valley is at its greenest. Lowest visitor numbers of the year, and prices to match.
June	Easing	Good	Rain tapers through the month. School holidays begin mid-June.
July	Second dry season	Good	Sunny and breezy, sometimes windy. A good month that few northerners think of, because it isn't winter at home.
August	Mostly dry	Good	The Feria de las Flores, the flower festival, in the first half of the month: parades, the silleteros, the whole city out. Wonderful, crowded, and the second price spike of the year.
September	Rain returns	Good	The second wet season begins. Afternoon storms; still warm.
October	Wettest month of the year	Deteriorates	The rainiest stretch, with the second air-quality season starting late in the month.
November	Wet, easing late	Often poor early	Rain eases toward the end of the month. Air-quality alerts common early. Prices are low until the December surge, which makes late November a smart arrival if you don't mind a wet first fortnight.

Rain and air patterns from IDEAM climate normals and the city's SIATA air-quality reporting; the character of each month is my description from living here. Individual years vary, and El Niño and La Niña years shift the wet seasons noticeably.

The best windows for a winter stay

• The classic: early December to mid-March

  The whole dry season plus the lights. You'll pay peak rent for December and January, and you'll be here for the best weather Medellín has. Leave before the March air season if you have any lung issues.

• The value window: mid-January to mid-April

  Miss the holiday price spike and the December crowds, keep all of January and February, and accept some afternoon rain and the March air in exchange for a noticeably cheaper apartment.

• The long winter: mid-November to mid-May

  Close to the 180-day maximum. Wet at both ends, dry in the middle. Cheapest per month because you're a long-term tenant, and the one I'd only recommend after you've done a shorter winter and know you like it. Run it through the calendar; it's tight against the tax line.

• The one people forget: July and August

  Dry, sunny, and it's the Flower Festival. Not a winter escape, but if you're avoiding a northern summer or a hurricane season, it's the other good time.

What to pack

Spring clothes. Light layers for days in the high 70s, a sweater or light jacket for evenings in the low 60s, and a compact umbrella you'll use most afternoons in the wet months and never in January. Comfortable walking shoes with grip, because sidewalks are uneven and can be slick after rain. A wide-brimmed hat and strong sunscreen; the sun at this altitude burns faster than the temperature suggests. Leave the parka, the shorts-only wardrobe, and the beach gear at home; if you go to the coast for a week, you can buy what you need there. And bring every prescription you'll need for the full stay.