Honda FourTrax Rancher TRX420FE1 2019 Owner's Manual page 182

Tires
Always check air pressure when your tires are "cold." If you check air
pressure when your tires are "warm" — even if your ATV has only
been ridden for a few miles — the readings will be higher. If you let
air out of warm tires to match the recommended cold tire pressures,
the tires will be under-inflated. Be sure to check tire pressure at the
riding site, since changes in altitude can affect air pressure.
The recommended "cold" tire pressures are:
RECOMMENDED
PRESSURE
172 Servicing Your Honda
FRONT
4.4 psi (30 kPa)
REAR
4.4 psi (30 kPa)