Nouns ending in -té are usually feminine, but le comté is masculine.
Comté is one of the rare exceptions: learn it as it is.
Is comté masculine or feminine?
lecomtéexception
The rule behind it
91.3% of -té nouns are feminine
In context
Combien de comtés y a-t-il en Floride ?
How many counties are there in Florida?
Sami vivait dans un comté très rural.
Sami lived in a very rural county.
Combien la Floride compte-t-elle de comtés ?
How many counties are there in Florida?