C182 ENCOUNTERED ICING WHILE AT CRUISE ALT. PLT DESCENDED AND WAS BELOW MIN SAFE ALT BEFORE ACFT PERFORMANCE WAS SATISFACTORY. PLT DIVERTED TO AN ARPT WHERE VMC PREVAILED.

Narrative

I FILED AN IFR FLT PLAN AND RECEIVED A COMPLETE WX BRIEFING. I WAITED TILL A FRONT OF WX WENT THROUGH THE AREA AND THE WX WAS EXPECTED TO BE BETTER AFTER THE FRONT PASSED. I WAS FLYING ON AN IFR FLT PLAN FROM ZZZ1 TO ZZZ2 AT 8000 FT ABOVE THE CLOUDS. WHEN I GOT CLOSER TO THE ZZZ2 AREA; THE CLOUDS WERE HIGHER THAN 8000 FT AND BEING ON AN IFR FLT PLAN; I ENTERED THE CLOUDS AND STARTED TO DEVELOP ICE ON MY WINDSHIELD. I REQUESTED ATC TO DSND TO 4000 FT. THE PITOT TUBE FROZE AND THE AIRSPD INDICATED 0 AND THE PLANE BECAME UNSTABLE DUE TO ICE BUILDING ON THE WINGS. I WAS CONCERNED I MAY BE CLOSE TO STALLING DUE TO ICE ON THE WINGS AND I LOST ALT TO 1800 FT AND WAS TOLD BY ATC THAT I WAS BELOW MINIMAL SAFE ALT OF 2500 FT. I WAS ABLE TO GRADUALLY CLB TO 3000 FT USING FULL PWR AND REQUESTED TO DIVERT TO ZZZ3 WHERE THE WX WAS RPTED TO BE BETTER. I BROKE OUT OF THE CLOUDS NEAR ZZZ3 AND MADE THE VISUAL APCH TO THE ARPT. APCH CTL WAS VERY HELPFUL IN ASSISTING ME IN THIS DIFFICULT SITUATION AND I WOULD LIKE TO CONVEY TO THEM MY THANKS AND APPRECIATION.