I’ve had a request to show Winter (Dec/Jan/Feb) temperatures by state. I am showing from 1998. That would be to Dec 2012 / Jan+Feb 2013.
Only two states have a warming trend. Maine and Vermont. South Dakota is cooling at -41F/Century. The full list is below the graph.
Click for bigger.
| State | Trend in F/Decade |
| South Dakota | -41.7 |
| North Dakota | -38.2 |
| Minnesota | -36.9 |
| Nebraska | -36.1 |
| Iowa | -33.2 |
| Utah | -32.7 |
| Wisconsin | -27.4 |
| Kansas | -24.2 |
| Colorado | -23.7 |
| Wyoming | -22.9 |
| Illinois | -21.5 |
| Montana | -21.5 |
| Indiana | -20.1 |
| Ohio | -19.4 |
| Kentucky | -18.3 |
| Missouri | -17.9 |
| West Virginia | -17.8 |
| Nevada | -17.1 |
| Pennsylvania | -17 |
| New Mexico | -15.9 |
| Michigan | -15.2 |
| Rhode Island | -15.1 |
| Arizona | -14.7 |
| Idaho | -14.3 |
| Oklahoma | -13.8 |
| Oregon | -12.3 |
| Texas | -12 |
| Arkansas | -11.8 |
| Washington | -11.3 |
| Tennessee | -11.2 |
| Maryland | -9.8 |
| Massachusetts | -9.2 |
| North Carolina | -7.9 |
| Alabama | -7.6 |
| New York | -6.9 |
| New Jersey | -6.7 |
| Louisiana | -5.4 |
| Mississippi | -5.3 |
| Delaware | -5.1 |
| Virginia | -5.1 |
| Georgia | -4 |
| Florida | -3.4 |
| South Carolina | -2 |
| California | -1.7 |
| Connecticut | -1.3 |
| New Hampshire | -1.3 |
| Vermont | 3.4 |
| Maine | 7.4 |
sunshine hours 
Thanks for doing winters–very useful stuff. I’m plotting up some of the data to use–how should I cite the source?
Just the web address is fine