dry season vs time of year

dry season and time of year both are nouns.

Word	Noun	Adjective	Verb	Adverb
dry season	Yes	No	No	No
time of year	Yes	No	No	No

As nouns, time of year is a hypernym of dry season; that is, time of year is a word with a broader meaning than dry season:

dry season: one of the two seasons in tropical climates, a yearly period of rainfall in the tropics
time of year: one of the natural periods into which the year is divided by the equinoxes and solstices or atmospheric conditions

Other hypernyms of dry season include season.

dry season (noun)	time of year (noun)
one of the two seasons in tropical climates, a yearly period of rainfall in the tropics	one of the natural periods into which the year is divided by the equinoxes and solstices or atmospheric conditions