Does the airline cold-weather pet embargo apply to in-cabin pets?
No — at American, Delta, United, Alaska and Southwest, no temperature or cold-weather restriction binds an in-cabin (under-seat) pet, as of 2026-09-11. Only American publishes a temperature rule at all, and it explicitly scopes that rule to checked pets and American Airlines Cargo.
What each airline actually publishes
| Airline | What it publishes | Applies to in-cabin? | Source |
|---|---|---|---|
| American | “We have temperature restrictions to make sure checked pets and pets traveling with American Airlines Cargo aren’t exposed to extreme heat or cold… You cannot travel with a pet if the ground temperature is below 45 degrees Fahrenheit (7.2°C)… If the temperature is below 20 degrees Fahrenheit (−6.6°C), your pet cannot be checked even with a letter from your vet.” Heat: above 85°F (29.4°C); Phoenix, Tucson, Las Vegas and Palm Springs are embargoed for “pets not traveling in cabin” May 1–Sep 30. | No — the rule's own heading scopes it to checked pets and AA Cargo only. | Read → |
| Delta | No temperature or cold-weather clause anywhere on its in-cabin pet page — the page covers fees, kennel specs, seating and country-by-country cabin exceptions in detail, with nothing on temperature. | N/A — Delta runs no general pet-cargo program (only military/State Department transfer orders). | Read → |
| United | No temperature or cold-weather clause anywhere on its pets page — the page covers fees, carrier dimensions and CDC/USDA import rules in detail, with nothing on temperature. | N/A — United no longer offers general public pet cargo (military/State Department only). | Read → |
| Alaska | No temperature clause on either its in-cabin or baggage-compartment pet pages. The baggage-compartment page does list permanent, undated destination embargoes (all of Europe, Japan, Seoul, and others) — those are geographic/health rules, not seasonal cold-weather ones. | No — cabin page carries no restriction; the baggage-compartment embargoes it does publish are destination-based, not temperature-based. | Read → |
| Southwest | “We welcome small, vaccinated domestic cats and dogs in an appropriate pet carrier in the cabin on domestic flights… No pets are transported in the cargo compartment.” No temperature clause anywhere on the page. | N/A — Southwest carries pets in the cabin only; it has no cargo program to embargo. | Read → |
The one real rule, and who it's for
American's cold-weather threshold is real and specific — no travel below 45°F ground temperature, a hard floor of 20°F even with a veterinarian's letter — but its own page states it in a section titled for "checked pets and pets traveling with American Airlines Cargo." A carry-on pet riding under the seat in front of you is neither.
Why this is worth checking directly
Search results and forum threads often repeat "airlines embargo pets in cold weather" as a blanket rule without saying which service it covers. It's a real rule — for cargo. If your pet is small enough to fly in-cabin, per our fit matcher, a winter departure city on its own is not a reason your trip gets refused at any of these five carriers.
Next: in-cabin vs cargo, the honest decision · check if your pet fits in-cabin · in-cabin fees by airline
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Every airline sets its own under-seat size, so the right carrier depends on who you fly. Pick yours for the carriers that clear its published limit: Southwest Airlines · American Airlines · Delta Air Lines · United Airlines · Alaska Airlines · JetBlue · Frontier Airlines · Air Canada · WestJet · all airlines →
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Sherpa Original Deluxe (Small)Mr. Peanut's Gold Series Mini (Low-Profile)Petmate Soft-Sided Kennel Cab (Medium)Mr. Peanut's Gold Series Standard (Expandable)Common questions
Does the airline cold-weather pet embargo apply to in-cabin (carry-on) pets?
No, at every major US airline checked (American, Delta, United, Alaska, Southwest) as of 2026-09-11. Only American publishes a temperature restriction at all, and it explicitly scopes that rule to checked pets and American Airlines Cargo — not to carry-on pets riding under the seat.
Which US airline has a published cold-weather pet rule?
Only American Airlines: no travel below 45°F (7.2°C) ground temperature, with checked pets refused outright below 20°F (−6.6°C) even with a vet's letter. It applies to checked pets and AA Cargo, not to in-cabin pets.
Why don't the other four airlines publish a cold-weather rule?
Delta, United and Southwest no longer run a general pet-cargo program for the public (cabin-only, aside from narrow military/State Department cargo exceptions) — a cargo-specific temperature rule has nothing left to apply to. Alaska's baggage-compartment page publishes destination embargoes instead of a temperature rule.