There is, depending on the game you are in.
Hidden Power typing depends on the IVs of the Pokemon, specifically whether they are odd or even. If you know the IVs, you can plug them into a calculator like this one: http://www.psypokes.com/dex/hp.php
In later games, there is also a NPC who will tell you the answer, such as the Nursery Lady in the Paniola Ranch in SM/USUM.
Edit: I see you tagged this as ORAS, so:
"In the second house from the left in the top row of Fortree City, you will find a house with these old women in. While one gives you TM10, Hidden Power, the one on the right will tell you what type your Pokémon's Hidden Power will be if it uses the move."
