Lincoln, Nebraska had its first 90 F or higher temperature of the year on June 1, 2010. How does this compare to the climatological normal? The attached graph shows the large variation from year to year.
The standard 30-year normal is May 21, or Calendar Day 141.
The average for the last 10 years, 2001-2010 is Calendar Day 125 or 16 days earlier than normal.
The 124 year average is Calendar Day 137 as noted by the horizontal black line in the graph.
Year 2010 was June 1, Calendar Day 152; or, 11 days later than normal.