MikroTik

hi friends
first of all excuse me for my bad english
i have an ptp link from home to work
groove with 23 db flat antenna on ap
metal 5 with 23 db flat antenna on station
ap side radio is on roof of my house 40ft
station side is on 60ft monopole tower
link tx / rx signal strenght normally is -70/-70
last year after rain and thunder my rx gone over -90
i did send metal 5 radio for repair and replaced damaged metal 5 with groove
link was fine untill 1 week ago
again after rain and lightning my rx gone over -90 with new radio
but this time radio was turned off
my tower is not hitting by lightning but after lightning radio rx increasing and link is not stable
i was wondering what can i do to prevent rain and lightning from damaging my radios ?
i dont have any grounding on tower
thank for your time

60ft tower will be picking up static electricity from all around, especially if there are no other tall buildings around.
Basic steps are making sure radio is grounded, use shielded cables (STP) and antennas that are electrically shorted.
If you search "grounding" here on forum, you will find some older threads about this topic with other helpful suggestions.