Here's a breakdown of the issues:
* "Es ist kalt heute" is correct German for "It's cold today."
* "Was das wetter im Kalifornian" is nonsensical. It seems like an attempt to translate "What's the weather in California?" but it's grammatically incorrect.
Here's how to correctly say "What's the weather in California?" in German:
* "Wie ist das Wetter in Kalifornien?"
This is the most natural and grammatically correct way to ask about the weather in California.