America's Most Weather Delayed Airports

T​ravel delays, including those from weather, become top of mind around the holiday season. So at what major airports are weather delays most likely?

Our methodology: We examined data from the U.S. Department of Transportation's Bureau of Transportation Statistics, looking at both the raw number of weather delays, as well as the percentage of all delay minutes due to weather at 30 major U.S. airports. The time frame we considered was from 2012 through 2019, then from September 2022 through August 2024, the most recent data available as of the time this article was published. We omitted 2020 through August 2022 to remove as much of the heart of the pandemic's effect on air travel as possible.

We ranked the airports in each categories, then added the rankings to come up with our composite index. The lower the index, the more weather-delayed that major hub was. In the case of a tie, we used the percentage of all delay minutes due to weather as a tiebreaker.

(Further beef up your forecast with our detailed, hour-by-hour breakdown for the next 8 days – only available on our Premium Pro experience.)

10. Philadelphia International Airport (PHL)

10-Year Arrival Statistics

-Weather delays: 76,213 (14th most)

-Percent of time delayed due to weather: 42.4% (seventh highest)

-Composite index: 21

-Weather issues: Low clouds/fog, wind, snow, thunderstorms

Philly sits in the middle of the pack in most of our weather criteria. For instance, it averages only about 23 inches of snow a year, with measurable snow 12 days annually. It's not especially windy, and with only 27 days a year with thunderstorms one wouldn’t expect that would contribute heavily to delays.

However, Philadelphia's ranking is best explained by clouds. Namely, when the cloud ceiling sits 700 feet or lower above the ground, expect flight delays.

Philadelphia is also a victim of its close proximity to other major Northeast airports and the propensity for delays there to ripple through the network.

9. Dallas-Fort Worth International Airport (DFW)

10-Year Arrival Statistics-Weather delays: 174,510 (fifth most)

-Percent of time delayed due to weather: 32.96% (12th highest)

-Composite index: 17

-Weather issues: Thunderstorms, fog, rare snow or ice

Hundreds of flight delays at Texas’s busiest airport can roll in when extreme weather fires up around the Metroplex.

A severe weather outbreak in North Texas on April 3, 2012, triggered 800 flight cancellations and 550 delays at DFW. More than 100 aircraft were damaged by baseball-sized hail. Some 1,400 people had to spend the night in the airport’s terminals.

But it doesn’t take tornadoes and huge hail to mess up flight plans in this hub. Slow-moving thunderstorms with heavy rain in the summer months can also push back flight schedules.

With annual snowfalls reaching only one to two inches on average, travelers should expect flight delays at this airport any time snow or ice is present.

8. George Bush Intercontinental/Houston Airport (IAH)

10-Year Arrival Statistics-Weather delays: 112,567 (ninth most)

-Percent of time delayed due to weather: 39.61% (eighth highest)

-Composite index: 17

-Weather issues: Thunderstorms, fog

H​ouston breaks a tie with Dallas based on its higher percentage of weather delayed minutes.

Thunderstorms can happen any time of year in southeast Texas, even while the rest of the nation is shivering in the middle of winter.

The key for weather delays is when these storms move slowly. Instead of a 30- to 60-minute delay, flights can be pushed back for more than an hour if a cluster of thunderstorms takes its time, as often is the case in Houston.

The city’s proximity to the Gulf of Mexico also makes it prone to fog. Houston is also at risk for tropical storms and hurricanes, primarily from June through September, but that didn’t factor into the data we studied for this list.

7. John F. Kennedy International Airport (JFK)

10-Year Arrival Statistics

-Weather delays: 97,930 (10th most)

-Percent of time delayed due to weather: 42.49% (sixth highest)

-Composite index: 16

-Weather issues: Snowstorms, low clouds/fog, wind, thunderstorms

The Big Apple makes its first appearance, but not its last, on our list with a yearly average of almost 100,000 weather-related flight delays.

New York City ranks just above the middle of the pack for both seasonal average snowfall (26 inches) and days with measurable snow in a year (14). Despite that, snowstorms can snarl air travel for a full day or longer at this airport.

More ordinary frontal systems can also cause delays when accompanied by low clouds.

6. Denver International Airport (DEN)

10-Year Arrival Statistics

-Weather delays: 180,067 (fourth most)

-Percent of time delayed due to weather: 38.93% (ninth highest)

-Composite index: 13

-Weather issues: Snowstorms, wind, thunderstorms, hail, tornadoes

Denver's main weather challenge is snow. Colorado Front Range snowstorms can occur as early as September or October and as late as April or May.

Wind is also a frequent problem. When strong crosswinds blow across certain runways, arriving planes would have to either use other runways or would be held at their originating airport. "Typically a strong westerly wind forces them off landing north or south," said The Weather Company meteorologist-in-charge Tim Burke, referring to Denver's north-south oriented runways. Even if delays aren't in place, Denver's winds can certainly make for a bumpy climb from or descent to the airport.

In late spring and summer, afternoon and evening thunderstorms can be almost a daily ritual. "They could go into a (ground) stop if low-level wind shear is reported due to outflows from dry thunderstorms," Burke told weather.com.

Under the right conditions, the Denver cyclone, also known as the Denver Convergence Vorticity Zone, can form near the airport. This is a boundary of converging air that can serve as another focus for thunderstorm development, some of which can spin up landspout tornadoes. Tornado sightings from the tower at DIA are not uncommon in late spring and early summer.

Given the propensity for thunderstorms and the high elevation, the Front Range is also a notorious corridor for large hail.

5. Boston Logan International Airport (BOS)

10-Year Arrival Statistics-Weather delays: 125,851 (eighth most)

-Percent of time delayed due to weather: 44.92% (fifth highest)

-Composite index: 13

-Weather issues: Snowstorms, fog

B​oston Logan's composite index tied Denver, but we nudged Boston ahead based on its higher percentage of delayed minutes due to weather.

According to Massport, the organization responsible for the condition of the airfield, most weather events don’t shut down the airport. Lengthy delays can happen, not just because of snow removal, but from delays at other Northeast hubs.

Boston Logan is also the windiest major airport in the country. A typical Northeast cold front can produce wind gusts over 30 mph.

Even the most prepared airport would have plenty of weather-related days with that much chaos swirling around it.

4. New York LaGuardia Airport (LGA)

10-Year Arrival Statistics-Weather delays: 152,563 (seventh most)

-Percent of time delayed due to weather: 54.71% (third highest)

-Composite index: 10

-Weather issues: Snow, low clouds/fog, wind, thunderstorms

LaGuardia Airport only accounts for 21% of the total passenger volume of the three major New York City metro airports, but is still prone to its share of delays.

Snowstorms are the most frequent instigators of massive flight delays and cancellations at the metro's big three airports, but aren't the only weather nuisance.

LaGuardia is situated on Flushing Bay, which allowed storm surge from Superstorm Sandy to flood its runways on Oct. 29, 2012. The water pushed far enough inland to reach terminal buildings and jetways.

T​he flood of Sept. 29, 2023, pushed several inches of water into LaGuardia's Terminal A, forcing it to shut down for several hours.

A line of thunderstorms ahead of an advancing cold front into the Northeast can also trigger significant flight delays on the order of several hours. Low clouds and fog can also trigger big delays.

We'll talk more about wind delays at these airports when we arrive at another NYC metro airport in our top 10 list.

3. Chicago O'Hare International Airport (ORD)

10-Year Arrival Statistics-Weather delays: 261,587 (most)

-Percent of time delayed due to weather: 45.91% (fourth highest)

-Composite index: 5

-Weather issues: Snow, low clouds/fog, wind, thunderstorms

No U.S. major airport had more weather delays in our 10-year study than O'Hare, averaging more than 26,000 weather delays a year. If an incoming flight is delayed to O'Hare, there’s an almost 50/50 chance it’s because of weather.

Only a lower percentage of overall delays due to weather knocked O'Hare down the list.

Weather systems in the Midwest generally move from west to east. Flights into O'Hare typically approach from the east. This makes flying around any adverse weather system a challenge.

Because Chicago averages more snowy days than any Northeast hub each year, wintry weather can be a major hassle for O’Hare. The Windy City sees about 28 days of snow per year on average, and O’Hare tops all major Northeastern airports with about 38 days with thunderstorms per year.

Then there’s the wind. South or southwest winds, the prevailing direction from June through November, can lead to delays even on sunny days.

Chicago is blanketed with dense fog about 13 days a year, which can happen at any time. Dense fog shrouded O'Hare the day before Thanksgiving in 2012 when traveler volume was extremely high. More than 100 flights were canceled and at least 300 more flights were delayed before the fog slowly dissipated.

2. San Francisco International Airport (SFO)

10-Year Arrival Statistics-Weather delays: 228,255 (second most)

-Percent of time delayed due to weather: 55.37% (second highest)

-Composite index: 4

-Weather issues: Low clouds/fog, wind

It's strange to see a city where snow is exceedingly rare and averages only two days a year with thunderstorms near the top of the list.

But the airport’s problems aren't from extreme weather – it’s usually fog and low clouds. When the marine layer is persistent, flight delays add up quickly.

In the warmer months, a pressure difference between the hot Central Valley and the chilly coast draws moist air from the cool Pacific Ocean into the Bay Area in the afternoon. This moist air then condenses overnight into low clouds, which hang in place until sunshine warms the layer enough to dissipate them the following morning.

Fog can be more dense during the winter months when cold air drains westward from the Central Valley and locks in.

There’s another problem that contributes to these weather delays: the layout of the airport’s runways, according to KQED. Only 750 feet separate two sets of parallel runways at SFO. When visibility is low, the FAA doesn’t allow planes to land side-by-side unless runways are at least 4,300 feet apart.

Arrivals must be staggered because of this conundrum, allowing only 60 to 65% of arrivals per hour compared to a clear day at one of the nation's busiest airports.

1. Newark Liberty International Airport (EWR)

10-Year Arrival Statistics-Weather delays: 190,539 (third most)

-Percent of time delayed due to weather: 62.85% (highest)

-Composite index: 4

-Weather issues: Snow, low clouds/fog, wind, thunderstorms

If you're late flying into Newark, weather is probably the reason.

W​hile tied with San Francisco in our composite index, Newark gets the nod at number one given its high percentage of all delayed minutes due to weather. In the 10 years we examined, there was an almost 2-in-3 chance a delay at Newark was due to weather, far more than any other major U.S. airport.

Snowstorms and occasional summer thunderstorms can cause problems, as we detailed earlier in the other two New York City Tri-State airport hubs.

You might be surprised to learn it’s the wind that creates issues most frequently at Newark.

Two of its three runways are oriented southwest to northeast. Common west to northwest crosswinds can create headaches for pilots attempting to land. This is why you could see planes circling Newark-Liberty on an otherwise picture-perfect afternoon.

T​he Staggering Facts On Delays

According to the U.S. Department of Transportation, about 26% of all arrival delays from September 2023 through August 2024, the most recent 12-month period of available data, were due to weather.

This amounted to 371,534 weather-delayed arrivals totaling over 28 million minutes. That's the equivalent of over 53 years of weather delays.

The FAA estimated flight delays in 2019 inflicted a $33 billion total cost on the U.S. economy. That's more costly than all but 10 U.S. hurricanes.

A 2007 congressional study estimated 740 million gallons of additional jet fuel was burned due to flight delays, about 5% of total fuel consumption.

A 2023 survey by the passenger advocacy group AirHelp found long flight delays and cancellations cost each affected passenger an average of $395 to cover such items as non-refundable costs, booking new hotels and food.

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Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him on Bluesky, X (formerly Twitter), Threads and Facebook.​