I have not had a lawn in over 25 years. it is one of the joys of mountain living with a native landscaped yard.
brown spots can have a number of causes, check out this link to sniff out a cause.
Last year we had brown spots show up in our lawn as well. In my case, and many others around here, it was a zoysia fungus called "brown patch". Might be related.
Can you post a photo? What type of grass do you have?
James, as much rain as we have been getting it very well could be a fungus already. Is it in a low spot, or did you have problems with that area last year? @Douglas Hunt is right, if you can post a picture or identify the grass we can be more helpful.