In August? No, unless you get cold in AC, no you won't need them. It's really, REALLY hot in late August. We are talking lows in the low 70's. We have gone to WDW the last week in August for the past 4 years and will be there again this year. All we ever pack are sundresses, shorts, t-shirts, sandals, swimsuits and rain ponchos. I say pack light and if you need something (which I don't think you will), just get it there. We went in February this year and it was in the 50's the whole time and we definitely needed long pants, sweaters and jackets, but you won't need any of these in August!