Narrative:

I was flying back from ZZZ at around XA00. I had called for a WX briefing and the briefer advised a convective SIGMET had ended 1 hour earlier; and en route stations were reporting VFR conditions -- 7-10 mi visibility and sky clear below 12000 ft. I checked the WX computer at the airport and confirmed what the briefer told me. I took off from ZZZ at XA15 en route to ZZZ2 when I encountered smoke from wild fires burning to the southwest of my route. Visibility gradually dropped below VFR minimums. I tried to follow road that I usually follow to get back; but realized I was descending too low for safety. I started a climb to 2500 ft; on a heading of roughly 330 degrees. At this point; I lost visual contact with the ground and was solely on instruments. I contacted norfolk approach for help and they started offering vectors immediately. They told me I was 5 mi south of ZZZ2; told me to descend and maintain 1500 ft; and asked me if I would like to go to ZZZ2 or ZZZ1. They advised me ZZZ1 was reporting VFR conditions-- 7 mi visibility; visual approach runway xx in use. I descended only about 100 ft before deciding ZZZ1 was the much better decision. They vectored me towards ZZZ1 on a heading of 320 degrees; then told me to spot the dehavilland at my 10 O'clock position and follow him in. After 2 mins; I advised approach that I could not spot the plane; and so they vectored me onto final approach. I could only spot the runway when I was about 3/4 mi from it. My biggest mistake was not to turn around immediately when visibility started deteriorating. My second mistake was a preparation mistake -- I should've had my approach plates with me and my low altitude en route charts; but nothing in the forecast led me to believe that conditions would be less than VFR. I think the only thing that couldn't been done was a warning offered to pilots during WX briefing that there is thick smoke in the area being pushed by the winds aloft. The winds aloft were really my only hint that smoke was drifting over my destination and I did not pay it enough heed.

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Original NASA ASRS Text

Title: NOTWITHSTANDING POSITIVE WX REPORTS; INEXPERIENCED C172 PLT ON VFR FLT PLAN ENCOUNTERS REDUCED VISIBILITY DUE TO SMOKE FROM WILDFIRES. RECEIVES ASSISTANCE FROM ATC TO DIVERT TO A NEARBY ARPT WHERE VISIBILITY WAS ONLY 3/4 MILE.

Narrative: I WAS FLYING BACK FROM ZZZ AT AROUND XA00. I HAD CALLED FOR A WX BRIEFING AND THE BRIEFER ADVISED A CONVECTIVE SIGMET HAD ENDED 1 HR EARLIER; AND ENRTE STATIONS WERE RPTING VFR CONDITIONS -- 7-10 MI VISIBILITY AND SKY CLR BELOW 12000 FT. I CHKED THE WX COMPUTER AT THE ARPT AND CONFIRMED WHAT THE BRIEFER TOLD ME. I TOOK OFF FROM ZZZ AT XA15 ENRTE TO ZZZ2 WHEN I ENCOUNTERED SMOKE FROM WILD FIRES BURNING TO THE SW OF MY RTE. VISIBILITY GRADUALLY DROPPED BELOW VFR MINIMUMS. I TRIED TO FOLLOW ROAD THAT I USUALLY FOLLOW TO GET BACK; BUT REALIZED I WAS DSNDING TOO LOW FOR SAFETY. I STARTED A CLB TO 2500 FT; ON A HDG OF ROUGHLY 330 DEGS. AT THIS POINT; I LOST VISUAL CONTACT WITH THE GND AND WAS SOLELY ON INSTS. I CONTACTED NORFOLK APCH FOR HELP AND THEY STARTED OFFERING VECTORS IMMEDIATELY. THEY TOLD ME I WAS 5 MI S OF ZZZ2; TOLD ME TO DSND AND MAINTAIN 1500 FT; AND ASKED ME IF I WOULD LIKE TO GO TO ZZZ2 OR ZZZ1. THEY ADVISED ME ZZZ1 WAS RPTING VFR CONDITIONS-- 7 MI VISIBILITY; VISUAL APCH RWY XX IN USE. I DSNDED ONLY ABOUT 100 FT BEFORE DECIDING ZZZ1 WAS THE MUCH BETTER DECISION. THEY VECTORED ME TOWARDS ZZZ1 ON A HDG OF 320 DEGS; THEN TOLD ME TO SPOT THE DEHAVILLAND AT MY 10 O'CLOCK POS AND FOLLOW HIM IN. AFTER 2 MINS; I ADVISED APCH THAT I COULD NOT SPOT THE PLANE; AND SO THEY VECTORED ME ONTO FINAL APCH. I COULD ONLY SPOT THE RWY WHEN I WAS ABOUT 3/4 MI FROM IT. MY BIGGEST MISTAKE WAS NOT TO TURN AROUND IMMEDIATELY WHEN VISIBILITY STARTED DETERIORATING. MY SECOND MISTAKE WAS A PREPARATION MISTAKE -- I SHOULD'VE HAD MY APCH PLATES WITH ME AND MY LOW ALT ENRTE CHARTS; BUT NOTHING IN THE FORECAST LED ME TO BELIEVE THAT CONDITIONS WOULD BE LESS THAN VFR. I THINK THE ONLY THING THAT COULDN'T BEEN DONE WAS A WARNING OFFERED TO PLTS DURING WX BRIEFING THAT THERE IS THICK SMOKE IN THE AREA BEING PUSHED BY THE WINDS ALOFT. THE WINDS ALOFT WERE REALLY MY ONLY HINT THAT SMOKE WAS DRIFTING OVER MY DEST AND I DID NOT PAY IT ENOUGH HEED.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.