A significant high-pressure system is bringing unseasonably cool and dry weather across various parts of the United States this week, with temperatures running about 10 degrees below average in areas like St. Louis and Baltimore. Many regions, including Clarksburg, Washington, and Colorado Springs, are experiencing cooler temperatures reminiscent of early fall, with highs in the 70s and lows in the 40s to 60s. This pattern is expected to persist through the weekend, gradually warming by next week. However, Texas faces an excessive heat warning, with heat indices reaching up to 110 degrees, posing significant health risks. No major precipitation is expected in most areas, potentially worsening drought conditions.