Airships are actually more efficient in cold climates. The craft gets its lift from the difference in density between air and helium. As the temperature drops

Airships are actually more efficient in cold climates. The craft gets its lift from the difference in density between air and helium. As the temperature drops air gains more density (in absolute terms) than helium. In the early days of airships this caused quite a problem, since it meant you had to vent hydrogen at night when your ship was too light, and then drop ballast in the morning when it was too heavy. As the day progressed the sun would warm up the helium, making the ship too light again. That's the big benefit of hybrids - since the ship is heavier than air it's tolerant of temperature-induced changes in buoyancy.