Regions across the U.S. are experiencing significant weather changes, with Northern California seeing a cooling trend this weekend after a period of intense heat. Temperatures in areas like Sacramento are expected to drop to the 80s, although fire risks remain high due to dry conditions. In contrast, San Diego County deserts are under excessive heat warnings with temperatures forecasted to reach up to 118 degrees. Meanwhile, Northwest Arkansas will enjoy a brief respite from the heat with seasonal temperatures in the upper 80s to low 90s, before a heatwave hits next week. Residents are advised to stay hydrated, avoid outdoor activities during peak heat, and be mindful of fire risks.