Despite the fact that the weather is lousy at this time of year in Southeast Asia it qualifies as high season.
We tend to visit between Nov and March and for the last few years I've been getting great tickets to Singapore for between $750 and 850. This month I was shocked to price out some tickets on UA for this summer (JUn-July) SFO-BKK it looks like we'll have to pay @ $1300 and that isn't an upgradeable fare!