Thursday, May 24, 2018

Mexico City Climate: Seasons, Sun, Sky, Clouds and Rain

People, both estadounidenses (United Statesians) and Mexicans, frequently ask us why we moved to Mexico. Since we have been asked often over the past ten years, we have developed a very succinct answer (in both English and Spanish), "For the three Cs: climate, cost and culture. (el clima, el costo y la cultura.)" This blog is very much about the culture, particuarly that of Mexico City and its many, very different colonias, pueblos and barrios, i.e., in over-simplified English, its neighborhoods. The cost factor is totally a pragmatic one, and with the present currency exchange rate for U.S. dollar conversion to Mexican pesos, much in our favor.

Climate we list first because that it what first attracted us, along with the culture, to visit Mexico. It only took barely escaping back-to-back snowstorms in New York one February and landing in Cancún, with its intense blue sky, aquamarine waters and warm sun, to convince us: "No more Winters!" However, Cancún, on the Caribbean coast, and both coasts of Mexico, beautiful and warm as they are in Winter, are extremely hot and humid in the Summer. Having lived with Northeast summers all of our life, we didn't need more of that!

So in looking for a place to live year-round, permanently, in Mexico, we headed for the hills, i.e., the high plateau of Central Mexico know as el Bajío (5,500 to 6,000 ft., 1,700 to 1,900 meters above sea level) and the cross-country mountain chain called the Eje Volcánico, the Volcanic Axis or Trans-Mexico Volcanic Belt. Most of the valleys between the volcanoes, where cities and larger towns are located, are about 7,000 ft (2,150 meters) above sea level.

We found Pátzcuaro, a small, charming, tranquil Spanish Colonial city on Lake Patzcuaro, in the pine covered mountains of the State of Michocán, fell in love with it and moved there in August of 2008. Three years later, as former New Yorkers, we decided we needed a more urban environment and moved to Mexico City. Both are in the Volcanic Axis, at virtually the same altitude, with the same climate.

The Seasons in Mexico's Central Highlands


Here, in the midst of the high mountains, Spring, interestingly, is the hot season. Afternoon highs are in the 80s Fahrenheit (27 Celsius and up), occasionally hitting 90 (32 C), but because of the altitude, the air is dry, so the heat is not oppressive during the day, and the air cools rapidly after the sun goes down.

Summers are actually somewhat cooler because, from May through September, it is the rainy season. The frequent late afternoon or evening thunderstorms, triggered by the day's heat, act as natural air  conditioning, cooling the evening air and usually keeping the next day's afternoon temperature in the mid to upper 70s. As the sun is usually out summer mornings and into the mid-afternoon, who could ask for anything more?

The "Winters" (November through February) in this highland part of Mexico can have chilly nights, in the 40s, even an occasional frost in December or January. When the sun comes up (earlier than in northern latititudes), it quickly warms the air and by afternoon, temperatures are in the upper 60s to low 70s. (Because temperatures can rise and then fall as much as 30 degrees Fahrenheit each day, Mexicans say they have four seasons in one day.) There are occasional cloudy days, once-in-a-while with some sprinkles or light showers (called las cabañuelas), when day-time temperatures only reach the 60s. With no central heating in homes, those days are a challenge to be met with gas or electric space heaters and sweaters.

Late Winter day

Personally, we call the season from November through February "Fling", a merging of Fall and Spring, because the deciduous trees (yes, there are many in addition to the palms and other siempre verde, always green ones) tell us the two "seasons" are happening simultaneously.

"Fall", i.e., the yellowing and fall of the leaves on deciduous trees,
happens from November through February.

Note the tree, mid far left, that already has its new, chartreuse green Spring leaves.

Each deciduous tree loses its leaves on its own schedule.
This one does so in January.

Three weeks later, it is sprouting its new "Spring" leaves.

By mid February, full "Spring" has occurred.

"Fling" (officially Winter) ends
with the glorious eruption of lilac blossoms of jacaranda (hah cah RAHN dah) trees in March.


Sun


It was the sun, with its winter warmth, that drew us to Mexico. The sun is central to Mexico's climate and thus, its culture and national identity. Of course, the sun is critical to all life in all parts of the planet, but here in Mexico, as in all of the tropics, its strength, on the many days that have clear skys, is potently, directly felt. Even in late December, it is toasty warm. From March through October, for eight months of the year, it produces a de facto Summer.

Of course, one cannot photograph the sun. But, from our wonderful, East-facing living room window, we (actually our early-rising spouse) can watch the sunrise. Amazingly, given our nearly 180 degree view, we can watch from day to day, week to week and month to month as the sun moves north from its most southern point at the winter solstice (meaning when the sun "stands still"), through the spring equinox (equal length of day and night) to the summer solstice in the north.

Sunrise at winter solstice, December 21.
It rises at the southern "foot" of the volcano Iztaccihuatl, the White or Sleeping Woman.
Popocatepetl, "Smoking Mountain", is to the far right.

Sunrise at mid Winter, February 2,
having passed north over Iztaccihuatl.
Also rises here at mid Autumn, November 2.

Sunrise at Spring (March 21) and Fall (September 21) equinox,
far north of Iztaccihuatl..

Zenith.
Because much of Mexico lies south of the Tropic of Cancer 
(23°26′12.8″ North),
the sun actually arrives directly overhead, at zenith, at noon on two days of the year.


In Mexico City (
19°26′N) this occurs on May 15 at 1.35pm Central Daylight Time.
Then, for ten weeks the sun moves through northern skys.
It returns to zenith on its way back south, on July 26.
At the zeniths (and days close to them),
shadows fall directly below the object casting them.

After the sun reaches its northern most point on June 21, we then spend the next six months watching it return south. The sun's movement along such a horizon constitutes humanity's first calendar (think Stonehedge). (Oh, and we can watch sunsets from our bedroom window, although the range of our view to the north is restricted, so summer sunsets aren't visible.)

Rain


The rainy season in Mexico usually begins with what we call "practicing" or the "run up" in April when, in late aftenoon, rain clouds form over the volcanoes to the east, but nothing more happens. Then, as the days progress, big, towering cumulus thunderhead clouds and lightening and thunder will be added and, perhaps, some sprinkles and finally, usually in May, a full-fledged thunderstorm, which can become torrential in mid-summer through September.

Towering cumulus cloud forms over the eastern mountains,
hearlding the approach of the rainy season.

Thunderstorm approaches

This year (2018), the clouds started forming at the end of February and by mid-March, we had a few sprinkles. Then, one afternoon, lightening and thunder were added, and we had an actual short shower. But it also brought the first rainbow of the year! They appear frequently, as the storms from the east often coincide with sunset. Our east-facing picture window and balcony provide the perfect viewing place, and the time coincides with wine and cheese before dinner!

Rainbow (with a faint double)
The Mexico City International Airport is about five miles northeast of us,
so we frequently see planes ascending.
(We call this photo "Why, oh why, can't I fly... Over the rainbow?")

Subsequently, we had thunder storms three nights in a row. One night, there were three waves of storms, with strong winds. Then, a sunset reflected against the dissipating storm clouds.


That onslaught was followed by two weeks of straight, hot sun. No rain. Then, one evening, when no rain was in the day's forecast, we had a sudden, intense thunderstorm. So goes the start of the rainy season: erratic and unpredictable (even for the weather experts).

So That's Why We Live in Mexico


Any more questions?