The jacarandas and the month they paint purple
Between late February and mid-April Mexico City changes colour. The jacarandas, which spend the rest of the year unnoticed as ordinary pavement trees, drop their leaves and cover themselves in purple flower at the same time along whole avenues, central reservations, squares and courtyards. No single street concentrates the phenomenon: it happens simultaneously on Reforma, in the Roma, in Coyoacán, in San Ángel and in neighbourhoods of no tourist interest whatsoever, and the ground turns into a sticky carpet that lasts for weeks. It is the most beautiful stretch of the year in an enormous, mostly grey city.
The tree is not Mexican: it came from South America, and its mass presence is usually credited to the Japanese gardener Tatsugoro Matsumoto, who early in the twentieth century proposed planting it in the capital when the city wanted a showy flowering tree for its avenues. The exact peak shifts every year and depends on how cold the winter was: some seasons the purple arrives by mid-February, others it holds on into the last week of April. Nobody announces it in advance and there is no official calendar, so look at recent photographs online before choosing the week you travel.
The dry window, month by month
The capital's dry season runs from November to April, and spring is its most pleasant stretch, right before it spoils. Between February and May the sky usually dawns clear almost every day, afternoons reach twenty-seven or twenty-eight degrees, and nights stay cool because of the altitude, so you walk comfortably from early on and sleep without air conditioning. It hardly rains at all, which means no afternoon collapses under a storm, something that between June and September happens here with almost clockwork regularity, generally at the same hour, and reshapes the whole shape of a day.
The price of that stability is that the air turns dry and dusty, and heat accumulates with nothing to wash it away. April and May are the hottest months of the year in the city, hotter than July, and the sun at two thousand two hundred and forty metres burns in twenty minutes even when the temperature feels mild. The rains usually break in late May or in June, almost always mid-afternoon and for an hour, and the air clears abruptly with them. Anyone after the balance of blue sky, purple flower and reasonable heat wants March.
Chapultepec and Coyoacán at their best
The Bosque de Chapultepec is enormous, free and at its best in spring: real shade, lakes, old ahuehuete trees and jacarandas scattered along the paths. Inside it sit the Castillo, with the finest view down Paseo de la Reforma, and the Museo Nacional de Antropología, still the most important museum in the country and worth a full half-day. Both close on Mondays, as almost every museum in the city does, and both cost little: entry usually runs between $4 and $10 USD (2025). On Saturdays and Sundays the park fills with local families, which is part of the appeal.
Coyoacán and San Ángel work as the counterweight: cobbled streets, low houses, bougainvillea and jacarandas hanging over the squares, with distances you can cover on foot. Coyoacán holds Frida Kahlo's Casa Azul, whose ticket should be bought online weeks ahead because it sells out, and which usually costs between $15 and $30 USD (2025); next door, the market serves tostadas mid-morning for a fraction of that. San Ángel keeps its Saturday bazaar and a handful of quiet squares during the week. At weekends both neighbourhoods are saturated; on a Tuesday morning they are another thing entirely.
The air in the dry weeks
The very weeks that turn the city purple are the worst weeks of the year for air quality. With no rain to wash the atmosphere, strong sun overhead and air sitting still in the valley, ozone climbs sharply in the afternoons between March and May, and dust and smoke from grass fires in the ranges around the basin are added to it. The result is a brown haze along the horizon, clearly visible from any rooftop, which never appears in the brochure photographs of spring in the capital. It is honest to say so before you book.
In practice this does not ruin a trip, but it is worth taking into account when you order the day. Mornings usually have far cleaner air than afternoons, so Teotihuacán, the park or any long walk work better early. When the authorities declare an environmental contingency, car circulation is restricted, including rentals and foreign plates, and outdoor exercise is discouraged. Anyone with asthma or a respiratory condition notices it; everyone else, at worst, ends the day with a dry throat and irritated eyes and sleeps it off without giving it much thought.
The empty city of Holy Week
Holy Week empties Mexico City like no other date in the year. Millions of residents head for the beaches and their home towns, traffic vanishes, there are seats on the metro, and avenues that are normally one continuous jam can be crossed in twenty minutes. For a visitor it is a strange and very comfortable week: the big museums generally open, the parks are calm and the city becomes walkable. In exchange, plenty of small businesses, neighbourhood fondas and workshops close from Thursday to Sunday, and some offices and banks too, so do not depend on paperwork.
The exception is Iztapalapa, where the Passion play has been staged for close to two centuries and usually draws hundreds of thousands of people on Good Friday. It is an enormous religious act, with a procession climbing the Cerro de la Estrella under brutal sun, not a show designed for tourists: go early, go light and accept the crowd. Beyond that, the rest of the country moves in the opposite direction, and buses and flights towards the coast fill up and rise in price weeks in advance. Flying anywhere within that week tends to cost noticeably more.
The mistakes people keep making
The commonest mistake is hunting for the jacaranda street, as if there were one specific spot to see the phenomenon. There is not, and people who insist end up spending two hours on the metro to reach a central reservation identical to the one on the corner by their hotel. The second mistake is timing: in spring the city is at its best from seven to eleven in the morning, when the air is clean, the light is good and the heat has not arrived. At three in the afternoon in April, walking the centre without shade is thankless work.
The third has to do with the city's own calendar. On Mondays almost every museum closes, the big ones in Chapultepec included, and plenty of people find that out with the day already lost. On Sundays, by contrast, several national museums waive entry for residents and fill to the doors. And the equinox on the 21st of March turns Teotihuacán into a pilgrimage of tens of thousands of people dressed in white: if the interest is the pyramid rather than the crowd, any Tuesday in March at nine in the morning is immeasurably better.
What people always ask
Six concrete questions about spring in the capital, answered without dressing up what cannot be fixed. They run from the most practical, which is exactly when the jacarandas flower, to the most uncomfortable, which is whether the air in March and April should make anyone move their dates. The short answer to the latter is that for most travellers it should not, and that the same weeks bringing the ozone also bring the best skies, the long evenings and the only season of the year in which no afternoon gets cancelled by rain.
One thing that does not fit in a short answer is worth adding. Spring is the season in which the city looks most like itself: flowers in the street, people eating outdoors, parks filling up in the late afternoon, and markets putting out mango, nopal and squash blossom. None of that depends on getting the exact week of the purple peak right. If the trip falls in February or in May the city will work just as well, with less spectacular photography and, in May, the advantage of somewhat cheaper rooms across the whole city.