No, the temperature did not get down to 30. There's a malfunction somewhere. If you look at the graph for that day, You'll see that it dropped more than 20 degrees in less than 1/2 hour. With no dramatic change in pressure. And no change in wind speed. This simply doesn't happen in the real world.
Also, take a look at Concord for the same day. No dramatic drop. Which re-enforces the malfunctioning weather station readings. You simply can't have 20-degree temperature differences within 30 miles under calm conditions!
