I just switched the weather station tile to use a PWS down the street from me, and the temp dropped 6 degrees. We’re on the coast side of the hills, while the zip code would cover a larger area (most not on the coast) and would likely be divergent from my local weather.
Take a look at the WU pws map near you, maybe someone nearby has a station? WunderMap® | Interactive Weather Map and Radar | Weather Underground