A weak or unstable GPS signal changes how your drone behaves, and knowing the warning signs before you're mid-flight matters.
Recognize the warning signs
Most flight apps show a satellite count and signal strength indicator before takeoff — treat a low satellite count (commonly fewer than about 7-10, though thresholds vary by drone) or an on-screen GPS warning as a reason to wait, not a reason to take off anyway. In flight, unexpected drift while hovering, or the drone failing to hold position in wind it normally would, are signs the GPS lock has weakened.
Common causes beyond geomagnetic activity
Flying near tall buildings, dense tree cover, bridges, or metal structures can all cause GPS multipath interference or signal blockage — this is a far more common cause of weak GPS than space weather, and worth ruling out first.
What to do if it happens mid-flight
Switch to an attitude or manual flight mode if your drone supports it, which relies on the accelerometer and barometer rather than GPS for stabilization and is less affected by a degraded satellite lock. Reduce speed, gain a little altitude if it's safe to do so (open sky generally means a stronger signal than close to obstructions), and land at the nearest safe, open location rather than attempting to return to your exact takeoff point in automated mode.
Don't rely solely on return-to-home during a GPS problem
Return-to-home is a GPS-dependent feature — during a genuine GPS problem, it may not function reliably. Retain manual control awareness at all times rather than assuming automation will resolve a GPS-related emergency.
After landing
If a weak signal recurs at the same location on different days, treat that as a site-specific issue (likely structural interference) rather than a one-off and plan around it in the future.