Here's the beginning of the 2011 rice season in three graphs*: Degree day (DD) accumulation over the developmental threshold of 55 oF (starting May 1st) during early May in 2011 was similar to 2008 and 2009.
The last couple of weeks we had some unusually cold weather. Some days, daytime temperature was 20 degrees below the average for this time of the year. The graph below compares average maximum daily temperatures with actual 2011 maximum daily temperatures during April and May in Colusa County.
