I went October 2005.
Played Gullane 2 and 3 - Windy Overcast Very Pleasant
North Berwick - Howling Wind, Cold, Difficult though 2nd 18 the wind sat down a bit
Dunbar - 18 holes of drizzle, cold
TOC - Down pour for the 1st 7 holes steady rain for the next 7 and it stopped for the next 4, cold.
Crail - with FBD in shirtsleeves and sunny.
Was it ideal, no. Would I do it again, in a heartbeat.
Cheers
Stan