Click the Hebrew word above to hear it pronounced.
The Hebrew word for summer is קַיִץ (KAH-yeets), probably related to the Biblical Hebrew word for end – קֵץ (kehts), as summer can be seen as the end of the year (especially with Rosh Hashana coming up).
Now, you may know that Aramaic is a cognate language to Hebrew – that is, the two languages are very closely related. One of the minor variations between the two is that often when Hebrew uses the צ (ts) letter, Aramaic uses the ט (historically, a strong t sound).
So where in Hebrew the word for summer is קיץ or קייץ, in Aramaic it’s קיט or קייט. 
Hence the Modern Hebrew rendition of summer camp – קַיְטָנָה (kah-ee-tah-NAH). It’s a combination of Aramaic קייט and the diminutive ending, נָה (nah). 

Truth is, the word probably appears in ancient Aramaic texts meaning something else (as does אולפן – ulpan – see definition on the website). If someone can find it, please send to me!