A change of direction
Why would an airport repaint a runway that hasn’t moved?
Same strip of tarmac.
A different number.
Show me why
Magnetic north moved. The runway stayed put.
Runway numbers generally describe their direction relative to magnetic north, rounded to tens of degrees. Tampa’s January 2011 notice changed 18R/36L to 19R/1L as part of a renumbering prompted by magnetic drift.
A historical example, not today’s flight information. Renumbering follows coordinated updates; it does not happen automatically whenever a compass reading changes.
184° → 186°. Runway 18 → 19.
The pavement stays in exactly the same place.
Orange arrow: magnetic north. N: true north.
Heading scale below the runway is magnified.
January 2011 example · Checked 2026-10-05
The receipts
Tampa International Airport’s January 2011 designation notice and the FAA magnetic-heading convention.
Runway designations are labels, not counts. Any future 184° → 186° illustration must be labeled hypothetical; no Tampa angle is inferred.