A collective noun for dry weather is spell. eg. A spell of dry weather
Dry weather
Dry wit, dry weather, and dry wine.
dry sunny weather
drought can last but the simple dry weather wont
There is no standard collective noun for 'dry weather', however, the term sometimes used is a spell of dry weather.
the weather is dry rainy hot
Very dry weather.
Dry weather means no rain. A dry day means no rain today. A dry spell means no rain for a while. A dry region means a place that seldom has rain.
hot dry weather
it brings dry and clear weather!
the weather in Nubia is hot and dry