Wed Sep 17 21:40:00 UTC 2025: **Summary:**

San Diego County is expected to experience a warmup early in the week, with temperatures rising 5-10 degrees above average. This will be accompanied by tropical moisture bringing a chance of showers. By mid-week, temperatures will cool down as residual moisture from Tropical Storm Mario brings higher chances of rain, especially in the mountains and deserts. The rain is expected to linger through the weekend, with temperatures dropping slightly towards the end of the work week.

**News Article:**

**San Diego Faces Warmup, Then Rain as Tropical Moisture Arrives**

**By Dominique LaVigne and Ciara Encinas**

**SAN DIEGO (FOX 5/KUSI) -** San Diego County residents can expect a mixed bag of weather this week. A warming trend will kick off the workweek, with coastal and valley temperatures soaring 5 to 10 degrees above average for this time of year. San Diego could see highs of 82 degrees, Vista hitting 88, Chula Vista reaching 80, Escondido at 91, Alpine at 91 and Borrego Springs expected to reach 103 degrees. The rising temperatures will be accompanied by an influx of tropical moisture, potentially bringing scattered showers.

However, the heat won’t last. By mid-week, leftover moisture from former Tropical Storm Mario will usher in a cooling trend and increased rain chances. Coastal and inland valley regions face a 20 to 30 percent chance of rainfall, while the mountains and deserts could see rain probabilities ranging from 30 to 50 percent.

The National Weather Service predicts the chance of rain will persist through the weekend, with temperatures gradually decreasing. A weak ridge of high pressure will trap the marine layer along the coast, leading to clear skies by the end of the week.

For a detailed forecast, visit fox5sandiego.com/weather.

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