If your dog is too big for the cabin, it's flying cargo — and cargo has a temperature rule that catches people off guard every single summer. It's not just "too hot in Panama." It's every airport on your entire route, checked on the actual day you fly.
It's two limits, not one
Most people have heard of the heat rule. Far fewer know there's a cold rule too:
- Above 85°F (29.4°C): Pets are refused as cargo. This is the one everyone knows about.
- Below 45°F (7.2°C): Also refused — though an acclimation certificate from your vet can sometimes allow boarding down to a hard floor of 20°F (-6.6°C), below which no airline will transport a pet regardless of paperwork.
Why summer specifically is the danger window
Panama runs hot and humid essentially year-round, so the destination side of the heat rule is a near-constant risk from roughly May through September. But the rule cuts both ways depending on where you're departing from — a layover through a cold-weather hub in winter can trip the 45°F floor just as easily as a summer afternoon trips the 85°F ceiling.
The mistake people make is checking the weather forecast once, a month out, and assuming that's good enough. Forecasts are only reliable about 14 days ahead. A route that looked clear in April can be a different story the week you actually fly.
Brachycephalic breeds face an even tighter window
If your large dog is also a flat-nosed breed — Bulldogs, Boxers, Mastiffs, and similar — airlines apply a lower heat ceiling than the standard 85°F, on top of requiring a signed liability waiver and a larger, better-ventilated crate. Brachycephalic dogs overheat faster and have less margin for error in cargo.
Check your actual route before you book
Generic seasonal advice ("don't fly in summer") isn't precise enough to actually plan around. What you need is the live conditions and forecast for every airport on your specific route, checked close enough to your travel date that the forecast is actually reliable.
Written by Jon Flink, who moved to Boquete, Panama with his own pets in 2025 and runs the Pets to Panama™ community. Always confirm current temperature policy and your specific routing directly with your airline before booking — rules and thresholds can vary by carrier and aircraft.