Tucson tied with the warmest winter on record for the city. That means the temperatures for December, January, and February all added up to top the list, which dates back to the 1890s. This new record matches the old record set just last year.
As the month of March marches on, the temperatures continue to look warm. The trend for warmer winters and springs has been going on for quite some time thanks to the human and natural influences that lead to climate change. Since 1970, the average spring temperatures have warmed as much as 5.6 degrees. These average numbers are measured by the decadal time frame.
The Southwest is where the warming is most pronounced. However, across the nation average temperatures increased in most states with the notable exception in the High Plains or Upper Mid-West along with pockets in other areas.
The more dramatic increase in warming in the Southwest could be due to the drier spring conditions that have taken over the climate numbers. Drier generally means hotter in the desert. While the trend towards drier conditions in the Southwest is not as pronounced as the heat, the numbers do indicate lower average precipitation for Arizona over the decades since 1970. That trend is generally opposite in the northern half of the U.S. where the trends show an increase in precipitation.