Shipping year round generally shouldn't be an issue. Tips if weather might be an issue:
-Loosen strings sufficiently. If it is in extreme weather conditions, I might even loosen them almost completely. If it gets hot for example, glue joints get loosened up and the bridge could rip right off or bend if there is too much tension on the strings.
-If you are going to humidify, make sure there is no chance of leaking or condensation taking place. Ruptured humidipaks would be a disaster in transit.
-Sending the guitar in a decent case helps. It could slow down the rate of temperature change. Hard polyfoam cases usually are the best for this.
-Send using the fastest method possible
-Let the guitar acclimatize in the case/box once it reaches its destination if the temperature on the delivery truck is very different from the temp inside the house.
"Success grants its rewards to a few, but is the dream of the multitudes.
Excellence is available to all, but is accepted only by a few." - Christopher Parkening