Mind you, 6 months later I did the Wokingham half in same weather conditions and got my worse time ever. The only reason i managed to finish then was because the sweep vehicle was right behind me for the last 4 miles.
I did the Benidorm half a few years ago in bad weather. We were drenched even before the race started. That's when i got my last PB. My feet were so cold and numb i couldn't feel the pain of running faster.