Here we are, only four months into the year, and the major airlines have already tried to raise fares 13 times. According to this USA Today article, they were successful in eight of those attempts.
Southwest, which managed to avoid price hikes in the first part of the year, raised fares two times in a week, and says even with the hikes it's still not covering costs.
Those costs are primarily fuel related. Jet fuel is selling for $3.40 a gallon, compared to $1.25 a gallon a year ago. With prices like that, I suspect the fuel surcharges will just keep coming.