Is this highly unusual? Yes.
As a Minnesotan, this early spring makes me nervous because I feel like we will pay for this early spring with something awful later...a blizzard? a drought? freezes in May? People have talked about how this could a sign of global warming. Perhaps it is, but we'll only know it after we've experienced it. We can forecast all we want, but it is only after the trends are collected and analyzed can we draw conclusions. To borrow a cliche, hindsight is 20/20.
Since I can't worry about these dire predictions yet, I will get outside and enjoy the good weather.