Why Two Places at the Same Latitude Can Have Completely Different Climates

If latitude—a measurement of how far north or south a location is from the equator—helps determine how much solar energy a place receives, shouldn't places at the same latitude have similar climates?

Not necessarily. And one of my favorite examples comes from somewhere I've actually lived.

Medellín and Santa Elena: Sometimes the important direction is down

Medellín and Santa Elena, Colombia, are essentially neighbors. Santa Elena sits in the mountains immediately east of Medellín, and you can travel between them in about 45 minutes without moving meaningfully north or south. But they don't feel the same.

When I lived in Santa Elena, I could leave its cool, misty mountain air and descend into Medellín to noticeably warmer conditions. I hadn't traveled to a different part of Colombia, and I hadn't changed latitude in any meaningful way.

I went down.

That distinction tells us something incredibly important about climate. Latitude matters, but it isn't the only thing determining the conditions you experience.

Santa Elena sits at a considerably higher elevation than Medellín. As we discussed in the previous ClimoraLens article, What Actually Determines the Climate of a Place?, elevation can have a major influence on temperature. As you move higher into the atmosphere, air pressure decreases. Rising air expands and cools, helping make higher-elevation environments generally cooler than nearby lowlands.

So even in the tropics, where we tend to imagine heat and humidity, elevation can completely change how a place feels. You don't always have to travel north—or south in the Southern Hemisphere—to find cooler air. Sometimes you just have to go up.

Take a moment to look up Medellín and Santa Elena on a map. Look at how close they are. Then look at photos of their landscapes and, importantly, their elevations. Once you know what you're looking for, the difference starts to make sense.

And elevation is only one way geography can disrupt what we might expect from latitude.

Essaouira and Marrakesh: Same latitude, different relationship with the ocean

Now let's travel to Morocco. Essaouira and Marrakesh sit at almost the same latitude and are only about 100 miles apart. But there's one very obvious geographic difference between them: Essaouira sits directly on the Atlantic Ocean, while Marrakesh sits inland.

That matters because land and water don't respond to heat in the same way. Large bodies of water can absorb and store enormous amounts of heat and release it relatively slowly—which is one reason the world's oceans are such an important focus in monitoring the effects of climate change—while land heats and cools much more quickly. The ocean can therefore act as a temperature moderator for places along the coast.

Essaouira's proximity to the Atlantic helps keep its temperatures relatively moderate. Marrakesh, removed from that immediate ocean influence, can experience much greater heat—particularly during summer—and larger temperature swings.

Again, we haven't substantially changed latitude. We've changed geography.

Pull these two up on a map too. Notice where each city sits in relation to the Atlantic. Then look at photos of both places. You're starting to do something more useful than simply memorizing their climates: you're looking for physical clues that might help explain them.

Imagine latitude as one piece of information about a place rather than a complete climate diagnosis. Knowing where something sits north or south of the equator tells us something important about the solar energy available there, but then we need to look around. Is it coastal or inland? Is it sitting thousands of feet above sea level? Are there mountains nearby? What direction does the wind normally come from? What are the atmosphere and ocean doing?

Those questions start revealing the rest of the story. Sometimes, that story produces two places that seem like they shouldn't possibly exist side by side on the same latitude line.

Lima and Puerto Maldonado: Same latitude, radically different climates

Our last comparison might be the most dramatic. Look at a map of Peru and find Lima along the Pacific coast. Then move east across the country until you find Puerto Maldonado within the Amazon Basin. Remarkably, the two cities sit at nearly the same latitude, yet their climates are dramatically different.

Puerto Maldonado is hot, humid, green, and extremely wet. Rainfall is abundant throughout the year, supporting the lush environment we associate with the Amazon. Lima, meanwhile, sits in a coastal desert.

Yes—a desert in the tropics.

If latitude were enough to determine climate, that contrast would be difficult to explain. But now we know to look for more clues.

Along Peru's western coast flows the cold Humboldt (or Peru) Current. The cool ocean surface helps keep the air near the ground cooler and less likely to rise, which limits the development of the deep clouds needed to produce substantial rainfall. Then there are the Andes, an enormous mountain chain creating a major physical barrier between the Pacific coast and the moisture-rich Amazon Basin to the east.

On the other side of those mountains, Puerto Maldonado exists within an entirely different moisture environment. Warm temperatures, abundant atmospheric moisture, dense vegetation, and the larger circulation of the tropical atmosphere support frequent rainfall.

Look at photos of Lima and Puerto Maldonado side by side after finding them on a map. Don't just look at the cities themselves; pay attention to the surrounding landscapes. One is surrounded by an extraordinarily dry environment. The other sits within the Amazon rainforest. Yet they're in the same country at nearly the same latitude.

Latitude didn't stop mattering. It simply wasn't acting alone.

Latitude sets the stage. Geography changes the story.

This is one of the most important ideas to understand about climate. Latitude helps establish the broad amount and seasonality of solar energy available to a region, and then geography starts modifying what happens with that energy.

Elevation changes temperature. Mountains redirect airflow and moisture. Oceans store and redistribute heat. Distance from the ocean affects temperature variability. Ocean currents influence nearby air, and atmospheric circulation helps determine where air and moisture tend to move. All of these processes can interact with one another.

That's why drawing a straight line across a map doesn't give you a line of identical climates. Earth is far more interesting than that.

Start looking beyond north and south

We're often taught to think about climate vertically on a map: travel toward the equator and it gets warmer; travel toward the poles and it gets colder. At the broadest planetary scale, there's truth to that pattern, but it can leave us with an incomplete mental model of how climate actually works.

Medellín and Santa Elena teach us to look up and down. Essaouira and Marrakesh teach us to look toward and away from the ocean. Lima and Puerto Maldonado teach us to look at the entire system—ocean, atmosphere, mountains, moisture, and land working together.

So the next time you see two places sitting along roughly the same latitude, don't assume you know what their climates will be. Look at the landscape and the elevation. Find the mountains and the water. Think about where the air might be coming from.

Then ask the question at the heart of ClimoraLens:

Why is this place like this?

Latitude can tell you where you are on the planet, but it takes climate literacy to understand the place you're actually standing in.