IMO is all due to such lousy poor winters of no to little snow for any amount of time and all the temp swings, I recall back in the 80's early 90's when we had more consistent winters and longer periods of time with snow down,( I/m also a big time snowmobiler, so I know when we had snow and didn;'t and how long seasons have been)
and never seeing a tick on a deer I killed in northern PA
NOW< like everyone stated, there every where ALL YR long!
snow is far and few temps go from freezing to mid 50's ALL Winter
as fact, was in mid 50's here yesterday and snowing now!
used to be ticks were more a thing of below interstate 80, more of a southern issue
but now with warm winters all over,. low to NO snow, in places that sued to have weeks or more of snow down, they migrated IMO
and have set roots and ain't going any where,
we all best get used to them and work to stay safe when outdoors and then when come back in, do a inspection and or change/shower or ALL 3