This graph shows two measures of lumber prices: 1) Framing Lumber from Random Lengths through July 27, 2018 (via NAHB), and 2) CME framing futures.
Right now Random Lengths prices are up 15% from a year ago, and CME futures are up about 23% year-over-year.
There is a seasonal pattern for lumber prices. Prices frequently peak around May, and bottom around October or November - although there is quite a bit of seasonal variability.
Tariffs on lumber, steel and aluminum are impacting housing costs. And rising costs - both material and labor - are headwinds for the building industry this year.