I may use this workaround myself…
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Although the latest Sim Update fixed the Live Weather, there is still a daily bug when flying at a time range between 20-08 UTC. The in-sim Live Weather uses clouds and precipitation data from the Meteoblue weather forecast model at that time range instead of the current weather situation. This is the reason if you have experienced “wrong weather”. Wind, temperature, and pressure at the airports seem to be correct though because they are injected from METAR. The workaround for this is to use the free Live METAR add-on when flying at 20-08 UTC until Asobo fixes this.
https://www.flightsimulator.blog/2021/05/26/using-live-metar-with-live-weather/