Live Weather
The amount of information available when the sim is in "Live Weather" mode is very limited. We can access the nearest METAR up to a certain distance, beyond which we can only access outside air temperature, some information about a cloud we would be in and current precipitation type/rate.
Weather Presets
Funny enough, we have more data coming from weather presets than live weather. With weather presets, we have access to cloud layers and their composition, thunderstorm presence, temperatures, wind layers and everything else you have access to via the in-sim weather panel. This is the most precise weather mode for Immersion.
3rd party weather engines
3rd party weather engines are injecting their weather through the presets system. That way, we have access to all relevant information to create weather-driven effects.