A warming trend is expected in San Diego County for the beginning of the first week of summer, followed by gradual cooling into next weekend, according to the National Weather Service. By mid-week, temperatures are expected to be a few degrees above average along the coast and 5-10 degrees above average inland, NBC 7’s meteorologists said. For the first half of the week, widespread moderate to major heat risk is possible for the deserts, and widespread minor to locally moderate heat risk for the inland valleys and mountains. “A warming trend will continue into Thursday as high pressure builds over the western states, with Wednesday and Thursday likely be the warmest days,” the NWS said. “Daytime high temperatures on those days will likely be 5 to 10 degrees above average for inland locations with localized areas of moderate heat risk away from the coast, and areas of major heat risk in the low desert.” The marine layer will become more shallow, staying confined to coastal locations with gradual cooling expected for the second half of the week, the NWS said. A cooling trend is expected to begin Friday, with next Sunday being the coolest day overall. High temperatures will be within a degree or two of normal in the coastal areas and deserts while valleys and mountain daytime highs will be anywhere from 3 to 11 degrees below normal. The marine layer will again deepen with low clouds spreading inland to the coastal mountain slopes during the nights and mornings, forecasters said. Elevated surf and strong rip currents are set to continue with a persistent long-period southwesterly swell. Surf of 3-5 feet with local sets to 6 feet are expected at southwest-facing beaches. Expect locally hazardous swimming conditions, forecasters said. This story uses functionality that may not work in our app. Click here to open the story in your web browser. ...read more read less