What the heat does
An attached Las Vegas garage routinely passes 120 degrees in July and August. That heat thins conventional lubricants until they run off the parts they were applied to, it accelerates fatigue in springs already carrying permanent load, and it hardens and cracks the rubber bottom seal and the weather stripping around the frame. It also cooks plastic: opener gears, remote housings and sensor brackets all get brittle years earlier here than in a mild climate.
What the dust does
Fine desert dust is abrasive and it goes everywhere. It settles on photo eye lenses and reads as an obstruction, which is why a door that suddenly refuses to close in Las Vegas is so often a wipe with a cloth rather than a repair. It packs into roller bearings, where it turns a rolling part into a grinding one. And it sticks to any oily lubricant, forming a paste that does more damage than no lubricant at all.
Use the right lubricant
This is the single most useful thing in this guide. Use a garage door specific silicone or white lithium spray. Do not use a general purpose penetrating oil like the one in most garages: it is a solvent and a water displacer, not a lubricant, it thins in heat, and it attracts exactly the dust you are trying to keep out. Apply to rollers, hinges, springs, bearings and the top of the rail. Do not lubricate the track itself, which is a running surface, not a bearing surface.
The twenty minute annual routine
Wipe both photo eye lenses and check both lights are solid. Wipe the tracks clean with a dry cloth. Lubricate rollers, hinges, springs and bearings. Check the bottom seal for cracking and daylight. Tighten the visible track and bracket fasteners, which vibrate loose over a year of cycling. Run the balance test with the opener disconnected. Test the auto reverse by laying a roll of paper towel flat in the door path and closing it: the door should touch, stop and reverse.
What to do in the worst of summer
Avoid running the door repeatedly in the middle of a very hot afternoon if you can, particularly on an older opener: heat and duty cycle together are what kills motors. If the garage has a west facing door and gets full afternoon sun, expect the bottom seal and the sun facing photo eye to be the first two things to need attention.
What is not a homeowner job
Anything involving the springs themselves, the lift cables or the bottom brackets. All three are under load even with the door closed. Cleaning, lubricating, tightening visible fasteners and testing safety features are all fine. Adjusting or releasing tension is not.