According to NIWA, September was a notably warm and dry month in much of New Zealand. The monthly summary (pdf here) notes:
"Christchurch was the driest, Dunedin the sunniest, and Auckland the wettest of the main centres. Rainfall was below normal, and temperatures above normal in all five main centres. It was extremely warm and dry for the time of year in Christchurch. Sunshine hours were near normal in Wellington, and above normal in the four other main centres, with record values in Dunedin."
Did Ken see this coming? In one respect he did - his monthly summary (p274/5) warns that September could be unusually warm, but on the other hand he also expected the month to be wetter than average.
I've updated my rainfall and sunshine spreadsheet to include the September actuals, and Ken is doing slightly better than usual. On the rainfall front, he gets Wellington, Christchurch and Dunedin more or less right - although it's worth noting that he didn't pick just how dry the last two really were - but is way off for Auckland. Sunshine is another two hits/two misses month. Overall, his batting average remains around 50% - not better than chance. His almanac doesn't predict the wet, cold weather that's rushed up the east of the country this week, so he's off to a bad start for October.