prob needs some lube, but yes the weather could be a factor atm
when i lifted mine to clean them (i didn't clean very often) there was an awful lot of grime and dirt in there, I'm sure they were spring loaded to some degree...
Had another look at this today and the passenger side is definately catching on something. Feel more loose than the drivers side. I can actually lift up the headlamp washer with my fingers, the drivers side one is tighter and doesn't budge.
Tried spraying some WD40 but it made no difference.