The Brogues Rapidshare I'm Going To Amsterdam, Brussels, And Brogues At The End Of This Month. Do I Need A Sweater ?

I'm going to Amsterdam, Brussels, and Brogues at the end of this month. Do I need a sweater ? - the brogues rapidshare

I wonder what kind of clothes should I bring to the Netherlands and Belgium in this time of year. According to forecasts, will be around 66 ° C Min Max 57 ° C. And no information about good places to see and to eat and shopping is very much appreciated. Thank you!