CX3 .cellHeader .cellWeather .maxTemp {
  color: white;
  font-weight: bold;
  font-size: 90%;
}

.CX3 .cellHeader .cellWeather .minTemp {
  color: darkgray;
  font-weight: normal;
}

.CX3 .cellHeader .cellWeather .temperature {
  display: var(--displayWeatherTemp);
  padding-left: 5px;
  font-size: 90%;
}
 
.CX3 .cellHeader .cellWeather .maxTemp::before {
  content: " \25b2";  
}

.CX3 .cellHeader .cellWeather .minTemp::before {
  content: " \25bc";
}
 
.CX3 .cellHeader .cellWeather .temperature::after {
  content: "° ";
}

    useWeather: true,
                            displayWeatherTemp: true,
                                      weatherPayload:(payload) => {
                                 if (Array.isArray(payload?.forecastArray)) {
                                   payload.forecastArray = payload.forecastArray.map((f) => {
                                     f.maxTemperature = Math.round(f.maxTemperature * 9 / 5 + 32)
                                     f.minTemperature = Math.round(f.minTemperature * 9 / 5 + 32)
                             return f

I don’t remember what changes I made to get the degree symbol and up/down arrows. I’ll post here if I can find those changes.

Do you know if there a reference in that doc about the weather icon and 4 digit number after it?

from the doc

in custom.css

.CX3 .event .endTime {
   display:none;
}