Mexico City, the capital of Mexico, is one of the highest-altitude cities in the world. It is located in the Valley of Mexico, a high plateau at an elevation of 2,240 meters (7,350 feet) above sea level. The city’s altitude has significant effects on its climate, geography, and even its history.
Geography of Mexico City
Mexico City is situated in the center of Mexico, in the Valley of Mexico, which is surrounded by mountains on all sides. The valley is an enclosed basin that is approximately 2,400 meters (7,874 feet) above sea level. The surrounding mountains act as a natural barrier and help to trap pollution in the valley, which can lead to high levels of smog and poor air quality.
Climate of Mexico City
The high altitude of Mexico City has a significant impact on its climate. Due to its location, the city experiences a subtropical highland climate, which is characterized by mild temperatures and relatively low humidity. The average temperature in Mexico City is around 18°C (64°F) throughout the year, with the highest temperatures occurring in April and May. The city experiences a rainy season from May to October, with most of the rainfall occurring in the afternoon or evening.
Effects on Health
The high altitude of Mexico City can have significant effects on the health of residents and visitors. The lower atmospheric pressure at high altitudes can lead to a lack of oxygen, which can cause altitude sickness in some people. Symptoms of altitude sickness can include headache, nausea, dizziness, and shortness of breath. It is essential to take precautions when visiting high altitude areas, such as ascending gradually and staying well-hydrated.
Historical Significance
The high altitude of Mexico City has played a significant role in its history. The city was founded by the Aztecs in 1325 on an island in the middle of a lake. Due to its high altitude, the city was well-suited for agriculture, and the Aztecs were able to create an extensive system of canals and floating gardens to grow crops. However, the city’s location also made it vulnerable to flooding, which was a constant threat to the city’s inhabitants.
Altitude Illness in Mexico City
Altitude illness, also known as acute mountain sickness, is a condition that can occur when people ascend to high altitudes too quickly. It is caused by a lack of oxygen in the body due to the lower atmospheric pressure at higher altitudes. Altitude illness can be mild or severe and can affect anyone, regardless of their age, fitness level, or previous experience at altitude.
Causes of Altitude Illness
As mentioned earlier, altitude illness occurs due to a lack of oxygen in the body. At sea level, the atmospheric pressure is around 1013 hPa (hectopascals), whereas, at 3,000 meters (9,843 feet), the atmospheric pressure is around 700 hPa. This means that the air contains fewer oxygen molecules at higher altitudes, which can lead to altitude illness. Mexico City has an atmospheric pressure of around 775 hPa. That is a significantly less hPa than places closer to sea level, so if you live in lower elevations you could feel the difference.
Symptoms of Altitude Illness
Altitude illness can manifest in various ways, and the symptoms can range from mild to severe. The symptoms typically start within a few hours of reaching high altitude and can include:
- Headache
- Nausea
- Dizziness
- Fatigue
- Shortness of breath
- Loss of appetite
- Difficulty sleeping
- Rapid heartbeat
In severe cases, altitude illness can lead to fluid buildup in the lungs or brain, which can be life-threatening, but that is for much higher altitudes than Mexico City. In fact, most people who experience altitude illness in Mexico City only complain of feeling more tired than normal and having shortness of breath when doing normal activities.
Treatment of Altitude Illness
Mild cases of altitude illness can be managed with painkillers, rest, and plenty of fluids. In more severe cases, medication may be required to help reduce symptoms. Acetazolamide, a drug that helps to increase the amount of oxygen in the body, is commonly used to treat altitude illness. If you believe you are sensitive to high altitudes, you may want to check with your local doctor about getting a prescription. You won’t find this drug available in Mexico City, I have tried.
Don’t worry, it passes!
If you are one of the people who suffer from Altitude Illness while visiting Mexico, don’t worry it will pass! Altitude illness is mostly mild because Mexico City is just below the level where altitude illness is expected. If you experience altitude illness, which isn’t everyone, you may have the feeling of the flu coming on, just a tired feeling, that is the biggest complaint. This passes within 48 hours, 72 hours for some, but it isn’t debilitating. You will still enjoy your time.
My recommendation is not to plan your first day in Mexico City to be a high-activity day. It’s not the day to plan a bike ride around the city or go running in the park. I normally recommend guests spend their first full day in Mexico City taking the tourist bus in Mexico City. It’s a bus that takes you to all the points of interest in the city, and it’s a hop-off, hop-on system. So if the bus stops at an attraction you like, you can stay and catch a new bus later. It’s great to take the bus on the full routes the first day, get some photo ops, and make notes of the places you see along the way so you can explore them more on another day. This lets you get a good overview of the city and what to see while you are here, all from an open-air, double-decker bus, with less physical activity as your body adjusts on the first day.
