In an extremely good mood, often expressing joy.

बहुत खुश

English Usage: She felt extremely happy when she received the good news.

Hindi Usage: जब उसे अच्छी खबर मिली, तो वह बहुत खुश महसूस कर रही थी।

To a very high degree.

बहुत ज्यादा

English Usage: The weather was extremely hot yesterday.

Hindi Usage: कल मौसम बहुत ज्यादा गर्म था।