Figuring out pricing seasons at Disney World is slightly more complicated than first impressions may lead you to believe. For example, the answer to your question may depend on the level of resort where you plan to stay. Additionally, your vacation dates may fall under two different pricing seasons. Although calendars can change every year, mid-summer is usually considered a peak season and is generally more expensive than value periods such as January and February and early Fall, but less expensive than Holiday season at Disney World such as Easter time, July 4th, Christmas, and New Years.
To figure out the season of your stay, head over to the
Disney Resorts page, click on the desired resort, and then click on the "Room Types & Pricing" button. Also, for planning the cost of Disney trips, I usually head to mousesavers.com. Use the search tool to search for the article, "2010 Walt Disney World Resort Room Rates & Season Dates." Click on the applicable resort or resort category for pricing information.
For a great summary of seasonal pricing at Walt Disney World, see Erin F's answer to a similar question
HERE.