If you're thinking this late cold spell is historic, you're absolutely right. Take a look at the graphic above in the media player. We have to go back to the 1920s to see a last freeze this late. The average last freeze is usually in late March.
In fact, vegetation is suffering around the area due to these long lasting cold blasts. In Porter, they're having a hard time keeping their peach trees alive because of the sporadic cold air masses. Last we heard, they've lost about 70% of their crop even though they've exhausted all resources to try and keep the cold away from their trees.