These temps are only 20-25 degrees AN today though (excluding some outliers), whereas 30's in July would be over 50 degrees BN. A surge of warmth like this in winter is far more likely to occur than an "arctic outbreak" in July (in which 50's would even be a stretch).
We almost always get thaws, but as Julian said, it's the fact that it's coming with beautiful sunny and dry conditions. This is more reminiscent of a mid-to-late march day.