Do you have the open or closed system?
The 1st thing to do is too service coolant reservour to the proper level when the system is cool and the fluid is contracted.
When the cooling system is COOL, if you have an open system, open the pressure cap on the radiator and check the fluid level in the radiator. The coolant should be at the very tippy top of the radiator, no air in there what-so-ever. If there is some space, air, in the radiator, your coolant recovery system is NOT working. The most likely culprit is the valve in the pressure cap on the system.
When the vehicle is warmed up, check the upper radiator hose, it should be hard with 13-18PSI of pressure behind it, if it is soft and squishy, like no pressure is in the system, then you need a new pressure cap or you have a leak in the system. The cooling system unable to hold pressure can cause the temp to spike up suddenly at unusual times.
Finally check the fans, the thermal clutch on the engine driven fan wear out after a couple of years, one of the most common malfunctions is the switch over when it gets warm, the fan clutch, instead of increasing resistance and driving more air, actually slips even more when hot and moves less air after the bymetal spring, heated up, switch's the fan over.
Observe the electric aux fan, make sure it comes on when it should. If it does NOT, then trouble shoot and see if its the fan, sensor, relay, wiring, etc.