There are several synonyms for the word "bright and sunny". Some possible options include radiant, luminous, dazzling, vibrant, cheerful, and effulgent. Radiant and luminous suggest a glowing or shining quality, while dazzling implies an intense brightness that can be overwhelming. Vibrant and cheerful both connote a sense of energy and liveliness, while effulgent suggests a brilliance that is almost divine in nature. Each of these words can be used to describe a beautiful day, a happy personality, or a sparkling gem. Regardless of the context, they all evoke a feeling of warmth and positivity.