I saved $4 switching to PG&E EV electricity rates

I'll try the graphic one more time:

 

No "of course" about it. The efficiency of solar panels degrades with heat. I see my highest output on cool, bright days in March and September.

There are a lot of microclimates in the Bay Area which get very little coastal fog but moderate coastal temperatures. I live in one.

The temperature difference probably makes solar panels more efficient in these places than in Sacramento, which gets quite hot in summer.

 

Here is the graph of electricity costs to go with the usage over the last year since I've owned a PiP. My point perhaps is that for some there is a mindset or maybe obsession that you contract when buying a car like a PiP. Look at the number of posts that fret over ounces of gasoline used. In buying a PiP, that you would think would use more electricity, I found that I consistently use less, saving beyond just electricity in exchange for gas.

 

It would be interesting to get some data. It do agree temperature makes a difference as shown below. Of course there are other factors. Windy days are the best with less "stuff" in the atmosphere.
May 25 Max temp 78, Max kW 2.78 Energy 21.92 kWh
June 18, Max temp 80, Max kW 2.76 Energy 21.64 kWh
June 27 Max temp 98, Max kW 2.6 Energy 21.15 kWh
That's about a 4% difference for a 20 degree difference in temperature.
A modest morning fog might make a similar difference.
Where would you think there might be coastal temperatures with almost no fog?

 

I'll guess windy days help because the panel stays cooler.

You are missing too many variables to jump to that conclusion. It is also not supported by copious manufacturer data, or a simple model of thermodynamics. A couple thoughts:
First, the peak temp does not imply that the *median* temp was 20F higher through the collecting hours.
Second, a hotter day earlier might dissipate any clouds in the sky quicker.
Third, the panel temperature is wind dependent.
Fourth, note that the peak kW on the cooler day is 7% higher than the hot day.

Check out PVwatts for some monthly data. In my area spring and fall handily beat summer and winter. Summer is hampered by heat, and winter by clouds.

Addendum:
Nice reading to become a PV guru:
Performance of Photovoltaics Under Actual Operating Conditions | InTechOpen