The pet cabin is colder than the passenger cabin

TL;DR: pets travelling in the hold of an airplane experience significantly lower temperatures (10°C lower) than in the main cabin.

We live in Denmark, but spent 10 weeks in the USA last summer, taking our Mini Goldendoodle with us. At 13kg, she was too big for the main cabin, so we booked her a spot in the cargo hold.

Mavis, our Mini Goldendoodle, traveled with us on a transatlantic flight

Airlines state that there is a dedicated part of the cargo hold just for pets that has the same air circulating as the main cabin. SAS, who we flew with, told us there is usually space for four dogs per flight.

Dogs hate being alone and they hate loud noises. So the thought of Mavis alone in a dark, noisy cabin for 10 hours was stressful. Despite airline assurances that the air is the same, I decided to measure it with two UNI-T UT330C humidity/temperature/pressure dataloggers — one for the passenger cabin and one for the pet cabin.

We flew with two dataloggers — one in the dog crate and one in the main cabin

I set the dataloggers to record temperature, humidity and pressure every 20 seconds. These devices are well made and easy to use. I wish they had wifi built-in, but for €50 you can’t complain. The data showed that the temperature was consistently lower in the pet cabin than the main cabin:

The temperature was consistently colder in the pet cabin, dropping to 11.5°C (52.7°F)

We were in the air for 7 hours and 10 minutes and the pet cabin temperature dropped to it’s lowest — 11.5°C (52.7°F)— during the sixth hour of the flight. The typical temperature difference was 9 to 10 degrees colder in the pet cabin than the main cabin, which typically hovered between 21 and 23°C.

Here are the humidity and pressure readings from the dataloggers:

The pet cabin experienced higher humidity than the main cabin, which, according to this StackExchange answer, means that colder temperatures will feel even colder. I.e. the dog cabin feels even colder than the temperature measurements suggest.

The jump in pressure readings show that, after cruising at one altitude for 2 hours and 20 minutes, the airplane increased to a higher altitude for the rest of the flight.

In conclusion, it might be worth putting a blanket in your pet’s crate if you really have to fly with them. Mavis’ breed has a thick coat and she seemed fine after the flight. According to her fitness tracker (a Fitbark) she got 3–4 hours of sleep during the trip. Going forward, however, we will try to avoid flights with her as much as possible.