A long-duration heat wave will continue to impact the western U.S. in the form of dangerously hot temperatures, primarily effecting mountain and desert microclimates but also being felt inland. The coast remains the most mild, comfortable place to spend time, with temperatures only exceeding normal by a few degrees due to the influx of marine layer clouds and onshore flow each day. An Excessive Heat Warning will remain in effect for San Diego County mountain and desert locations through Thursday at the earliest as this long-duration heat wave will bring daytime highs in the 90s over the mountains and desert highs between 115 to 121 degrees. Temperatures like these will have us watching the records for the desert. Yet another Excessive Heat Warning is now set to take effect for inland/valley locations between Tuesday and Thursday of this week due to those likely being our hottest days of the week. MORE: https://www.cbs8.com/weather/