"Sunny weather is a good thing."
Translation:اَلْطَّقْس اَلْمُشْمِس شَيْء جَيِّد.
Because in English, the article means you speak about a specific instance (e.g. "The sunny weather (of today) is ..."), whereas no article means you speak about a general concept (i.e. "Sunny weather (in general) is ..."). Such a distinction doesn't exist in Arabic, and without context both should be accepted. However, the latter is more likely to be what was originally intended.