I calculated temperature anomaly for each day relative to a typical seasonal curve (spline for DOY vs. Max or Min temperature).
When I calculate the average anomalies over time by month since 1900 (y-axis is change in temperature in °F since 1900) a few things pop out that I'm not sure I've known before.
1) Daily minimum temperatures (blue) have increased more than maximum temperatures (red).
2) Spring warming has been greater than fall warming.
3) Falls might actually be cooler.