Wheat climbed to its highest since early May with the market on track for a second week of gains as dry weather in parts of North America threatens to reduce yields. Wheat earlier rose to as much as $4.58-1/4 a bushel, the highest since May 2. Wheat is rallying on concerns that recent dry weather will curb the output of the U.S. spring crop. North American spring wheat crops remain too dry and weather forecasters do not expect that to change.