Autumn temperatures are on the way, weather officials say, but summer continues to display tenacity. A record was set for September in the greater Sacramento area with 26 consecutive days of 90-degree or warmer temperatures. “It has been warmer than normal,” said Darren Van Cleave, meteorologist for the National Weather Service. What has been delaying the arrival of cooler, more seasonally consistent temperatures is a stubborn high-pressure system, known in the weather prediction business as a Rex Block, Van Cleave said. A Rex Block is a high-pressure system that establishes itself due north of a low-pressure system. The block is …