While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

El Niño and La Niña are Pacific Ocean climate patterns that affect global weather

El Niño causes warm water to move east, disrupting ocean life and bringing wetter conditions to the southern US and drier ones to the North. La Niña strengthens the usual wind patterns, triggering cooler northern winters and more storms in the Pacific Northwest.

Mapping how the El Niño-Southern Oscillation affects weather patterns around the world

In the warm episode (El Niño), summers in India, Indonesia, Australia, and the Caribbean are drier than normal, while winters bring wetter, cooler conditions to the US Gulf Coast and warmer conditions to the Pacific Northwest. During the cold episode (La Niña), these are reversed, with India, Indonesia, and the southern Caribbean experiencing greater rainfall in the summers.

How El Niño and La Niña affect the Pacific and Atlantic hurricane seasons

During El Niño, trade winds push warm waters across the Pacific toward northwest South America, affecting atmospheric circulation. The resulting strengthening of vertical wind speed and direction in the Atlantic basin disrupts hurricane formation, while the weakening of this wind shear in the central and eastern Pacific basins increases hurricane likelihood. El Niña, conversely, has the opposite impacts.

Comparing La Niña and El Niño atmosphere-ocean feedback patterns

During La Niña, trade winds reinforce the flow of warm ocean water from the eastern to the western Pacific, allowing colder subsurface water in the eastern Pacific to rise to the surface. These changes reinforce overhead air movements by altering the air temperature near the ocean surface. During El Niño, these trade winds weaken or reverse, preventing upwelling by shifting warm water back to the eastern Pacific and displacing atmospheric circulation patterns.

How jet streams and US weather are affected by the El Niño-Southern Oscillation

Jet streams are predominantly west-to-east air currents in the atmosphere that mark the boundary between cold polar air and warm tropical air, where cells of atmospheric circulation meet. By disrupting the location of these circulations on two- to seven-year cycles, ENSO alters the probability of droughts, floods, and above- or below-average temperatures across the US.

El Niño, Spanish for 'the boy,' was named after Jesus Christ because the phenomenon resembled the weather changes observed around Christmastime.

Breaking down the health effects of the El Niño-Southern Oscillation

Second only to the seasons, ENSO is the most significant source of variability in global climate, shifting rainfall and temperature patterns, particularly in Africa, Latin America, and South and Southeast Asia. The incidence of vector-borne diseases like malaria, respiratory diseases related to wildfire smoke, food insecurity, and drought-related health and nutritional impacts has been observed to be affected by ENSO.

Learn about various ocean-atmosphere cycles impacting global weather patterns

Although the El Niño-Southern Oscillation is among the most impactful, the North Atlantic Oscillation strongly influences weather patterns in the Northeast US by periodically changing atmospheric pressure over the Atlantic. The North Pacific Oscillation fluctuates atmospheric pressure and sea-surface temperatures that affect winter temperatures over much of the US.

The global impacts of the 1877 'super' El Niño and what could result from similar future events

The 1877 El Niño event lasted approximately 18 months, raised temperatures in the Niño 3.4 region of the equatorial Pacific Ocean by 2.7 degrees Celsius (4.86 degrees Fahrenheit) above average, and contributed to a global famine that killed more than 50 million people. Such events are expected to exacerbate drought-related risks to global food security, driving up food prices worldwide. (Some readers may experience a paywall.)

El Niño, Spanish for 'the boy,' was named after Jesus Christ because the phenomenon resembled the weather changes observed around Christmastime.

How scientists use data to anticipate the phases of the El Niño-Southern Oscillation

Sea-surface temperatures across various regions of the equatorial Pacific Ocean can be compared with ocean temperatures elsewhere in the tropics to identify anomalies that indicate where in the ENSO cycle Earth finds itself. The "Niño 3.4" region in particular—known as the Ocean Niño Index—is a key indicator of ENSO phase and intensity.

Watch a visualization of how Earth's oceans impact its atmosphere, weather, and climate

Data from NASA satellites help view and explain global climate and weather patterns, such as El Niño and La Niña.

Trade winds blow from east to west due to the Coriolis Effect

Warm air rises near the equator while cooler air sinks near the poles, creating circulation patterns that curve due to Earth's rotation. At the equator, doldrums—calm regions of no wind—build warm, moist air, creating storms.

Why the ozone hole altered Southern Hemisphere jet streams and rainfall patterns

Ozone depletion over Antarctica shifted jet streams southward, drying Australia while increasing rainfall in Uruguay, Brazil, Paraguay, and Argentina. Around the turn of the millennium, these trends began to slow as the Montreal Protocol phased out ozone-depleting substances.

Lightning storms are more common in coastal and tropical regions

Water-abundant areas that receive increased solar radiation, such as those near the equator, experience increased rates of evaporation, which produce tall clouds as moisture rises, cools, and condenses. Mountain ranges can also steer air to higher altitudes, creating collisions between atmospheric particles that generate charge imbalances—the precursors to lightning.

Monsoons are large, seasonal shifts in wind driven by land-sea heating differences

Because land heats and cools faster than water, pressure differences form and create significant sea breezes. Moist air pulled onto land rises, condenses, and leads to substantial summer rainfall.

Learn all about different types of extreme weather

Find out in more detail about different types of extreme weather, from flooding to thunderstorms, from tropical cyclones to sandstorms, and more (w/ helpful videos).

View the most turbulent flight routes and airports around the world

Using data from NOAA and the UK Met Office, these maps identify South America as the geographic region with the highest average turbulence. The most turbulent flights in North America are all found in the western United States.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

Drought conditions force fewer ships to sail the Panama Canal daily

In 2023, canal authorities reduced traffic in the canal amid severely dry conditions. These seven infographics from the Woodwell Climate Research Center explain exactly what happened that historically dry October, and how it affected global supply chains.

Atmospheric rivers are the largest freshwater transport mechanism on Earth

Serving as highways that carry the water vapor equivalent of up to 15 times the average flow of water at the mouth of the Mississippi River, atmospheric rivers are approximately 400 to 600 kilometers (250 to 375 miles) wide and provide 30-50% of the annual precipitation of the US West Coast.

As of 2025, the world's largest tropical cyclone spanned half the continental US

Typhoon Tip traveled across the western Pacific Ocean in 1979, achieving winds of 300 kilometers per hour. Though it weakened significantly before making landfall in Japan, its rainfall produced over 600 mudslides and killed 42 people.

Climate change creates conditions for more invasive species

Increasing temperatures shift the conditions native organisms are accustomed to, allowing those from warmer climates to move in with a greater chance of survival. Drought stress can cause invasive plants to absorb less herbicide, limiting the effectiveness of the control method, while melting ice can open new Arctic shipping routes, expanding the transport of species.

Why parts of the Earth are colder when the planet is closer to the Sun

The Earth orbits the Sun in an elliptical shape, and winter in the Northern Hemisphere occurs when the Earth reaches the point in its orbit closest to the Sun, known as perihelion. The lower temperatures result from the hemisphere tilting away from the Sun.

Side-by-side shots of once-dry California lakes now filled

In late 2022, much of California was in drought; by early 2023, after a series of downpours from atmospheric rivers, much of the state's reservoirs had been re-filled. See the dramatic difference in this series of photos.

Amazon rainforest facts, species, and threats

The World Wildlife Federation presents a brief overview of the Amazon rainforest, covering key facts like location, size, and importance. An overview of threats includes unsustainable resource extraction, climate change, and poorly planned construction projects.

Rare chance for US states to see Northern Lights

A solar storm in July 2023 offered people in 17 American states, as well as Canada, an unusual chance to witness the Northern Lights, or aurora borealis. The 11-year solar cycle, reaching its peak in 2024, made the lights visible in places further south than usual. Read up on the announcement from the Geophysical Institute at the University of Alaska at Fairbanks here.

Dirty lightning is a thunderstorm created from friction between rising and falling flows of ash and smoke during volcanic eruptions.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

See the 25 of the best photos of auroras from around the world.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Poison ivy will likely become both larger and more resilient due to climate change.

See how Ebola tore through Guinea, Sierra Leone, and Liberia in 2014-2016.

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Quincy Jones' 'Big Band Bossa Nova' helped introduce bossa nova—a jazz-influenced Brazilian genre—to the US