Date: 202105
Local time of day: 1201-1800
Location: IOW.Airport, IA
Weather elements / visibility: Fog; Rain; 2
Light: Daylight
Aircraft: Small Aircraft
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Initial Approach
Airspace: Class E ZAU
ATC / advisory: TRACON CID
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor
Human factors: Situational Awareness; Training / Qualification
Anomaly: Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors; Weather
Primary problem: Human Factors

Narrative: My wife and I were flying to IOW. The nearest airport to IOW with a TAF is CID; 16 NM to the northwest. The CID TAF at our estimated time of arrival was... 4SM -RA BR OVC015We planned on flying the flight VFR with only CID being a little marginal VFR. About 30 NM from IOW we encountered light rain and the OVC015 ceiling started to drop. We maneuvered right and left as we made our way toward IOW. The IOW ASOS at the time was reporting the ceiling 1100 scattered. At 15NM west of IOW at 500-600 feet AGL skimming the cloud bases; I turned around to get back to better weather; but found that the weather had closed in behind me; or my route in could not be duplicated out. I knew there were antenna towers in the area and got a visual on one of the towers which appeared to be near my altitude. The safety of the flight was now in question. I called CID Approach and requested an IFR clearance to IOW. The Controller cleared me to the IOW airport via radar vectors and gave me a heading and instructions to climb to 2;500 feet. I advised the Controller that I wanted to shoot the RNAV (GPS) 30 approach into IOW circle 7. We shot the approach; broke out around 1100 AGL; circled; and safely landed on Runway 7. I hold an ATP certificate; however my last instrument proficiency check I had was a 135 check [several years ago]. Therefore; I was not instrument current.Our airplane is equipped with a Garmin 400W and a Garmin 335 ADS-B out transponder. The 400W had a current procedures data base and the pitot static encoder check was completed [two years ago]; making [my aircraft] legal for IFR operations. Additionally; I had flightplan.com app loaded onto my phone; which allowed me to have current IFR low altitude charts and approach plates for IOW; as well as the surrounding area.My brief IFR flight and approach was performed to ATP standards and did not alarm ATC in anyway. I have reviewed my ADS-B track and found that the lowest I got on that flight was 422 feet AGL; which is lower than I recall. The antenna tower I saw is at 320 feet AGL. The low flight occurred in Class G airspace during the day. Complacency on my part was definitely a factor and I have taken steps so as to not repeat this occurrence. I have scheduled an Instrument Proficiency (IPC) check.




Synopsis: Pilot reported descending to 422 feet AGL during an encounter with unexpectedly poor weather.