Drones are a lot of fun, but they're made for fair weather. Winter weather is generally not the friendliest, but with a little thought and preparation, you can capture the beauty of winter landscapes from above.
Just like ice is an enemy of planes and helicopters, it's an enemy of drones. When it builds up on the propeller blades, it increases the craft's weight and negatively affects its aerodynamic properties. Keep this in mind, particularly when flying over a body of water, where the cold air on top of the warmer water can cause evaporative fog that refreezes on nearby surfaces, including your drone.
2. Staying Warm
Flying a drone the wintertime is a really cold experience. Because you're generally standing still the entire time, it tends to be colder than a lot of other winter activities. Be sure to dress appropriately; in particular, wear gloves that are warm, but still allow the requisite maneuverability to fly the drone. You'll also need to manipulate your phone/tablet, so gloves with capacitive fingertips, no fingertips, or a transmitter mitt are ideal. I've also taken to sitting in my car once it's in the air, but if you do so, be sure you can still maintain a clear line of sight as required by the FAA.
3. Battery Behavior
In colder temperatures, battery life is going to be shorter. Plan for this both in your flight routes and how you handle the batteries. Keep the batteries warm as long as possible. I generally keep the spares in my car unless I'm hiking far from it; if that's the case, I keep a hand-warmer in my backpack (don't place these directly on the batteries). You can also keep the batteries in your jacket, where your body heat will help keep them warm.
Once you're flying, begin by starting the motors and letting the drone hover for about a minute to warm up. Most DJI drones will warn you if the battery temperature drops below 15 °C; if you see this before taking off (check the temperature in the battery menu just to be safe), consider pulling the battery and warming it up. Because cold conditions can result in voltage drops, be mindful of things that tax the voltage, namely excessive maneuvering and prolonged high velocities. In short, go a little easier on the controls. Land a little earlier as well.
Rain, fog, snow: winter is full of airborne moisture, none of which is particularly friendly to the motors or sensitive electronics on your drone. You'll also have to deal with moisture on the lens and your phone/tablet screen. Avoid flying through fog (you'll lose line of sight anyway). While some people have flown in light snow successfully, I don't recommend it, and if you encounter rain, definitely land immediately. You'll also need to take steps to protect your phone/tablet's screen; if there's a light snow, I normally use the hood that comes with the controller and tilt the controller slightly to protect my phone. Lastly, be mindful of where you take off and land, as the propellers can kick up a fair amount of snow when they're near the ground.
Winter often means fog (particularly over bodies of water in the earlier stages of the season) and low cloud banks, both of which are often well below the 400-foot altitude restriction on drones. In addition to the threat of moisture, they can make it difficult to see your drone. Be aware of these. They can work to great artistic effect, but they also require some careful flying.
6. Good Air
It's not all gloom and doom in winter, though. There's less convective heating, which means smoother air, which means more stable footage and longer shutter times should you so desire. In the summertime, I typically max out at around a half-second or a second on especially calm days. However, in the winter, I've been pulling off eight-second exposures with no issue, which is rather remarkable considering my camera is flying.
7. Density Altitude
Another side effect of the colder air is the lower density altitude you'll be flying in. Simply put, colder air is thicker, which means the props take a larger "bite" of air, moving a greater mass of it backward and by Newton's Third Law, moving the drone more effectively. While the effect isn't drastic at these speeds and differences, you will notice a slight performance gain; whereas my Phantom 4 maxes out at 22 mph in summer weather, I consistently hit 24 mph in the winter.
8. Exposure and White Balance
First of all, shoot raw. Always. If you're not shooting in full manual, remember that a camera's exposure system will usually be tricked into underexposing snow, so you'll want to dial up some exposure compensation, typically about a stop or so. Second, you'll often find that the white balance skews toward blue a bit; so be sure to compensate for that as well.
I think post-processing is a highly personal process, but there are a few things to keep in mind when working with winter scenes. Because snow is white, diffuse, and typically takes up a lot of the scene, it's advisable to compensate for the lack of perceived detail. I typically do this by bumping the clarity and contrast levels a little beyond what I might normally for a landscape shot. In particular, this helps to bring out the unique geometry and structures created by the snow that might be easy to miss otherwise. The amount of fog and cloud cover you encounter will also have an enormous impact on this.
10. Winter Is Weird
Winter can look particularly otherworldly from above. Whereas my summer shots are more traditional in nature, I've been heavily drawn to the abstract scenes I've seen from above. Open your creative eye a bit and look for shot opportunities you might not normally pursue. Look for interesting structures and patterns.
Lastly, be smart. There are added considerations when flying a drone in the winter, so be sure to read your manual, take the right precautions, and fly safely. Have fun!