The National Weather Service is currently predicting a low of 11F for Bedford, MA and a low of 12F for Natick, MA. I find these forecasts hard to believe. Why? Because around 2pm today, the dew point shot up to 11F in Bedford and 13F in Natick and the dew point is currently 15F in Bedford and 17F in Natick. Yes, it is certainly possible that the dew point could drop overnight. But, I think more likely is that the jet stream shift that was due arrived a bit earlier than expected and the NWS has not used the sudden change in dew point as an indicator. Based on recent experience, late evening dew point has served as a lower bound for overnight temperature, so I'd be very surprised to see the NWS predictions come true. I'd bet that the overnight low will be around 20F in Natick and 17-18F in Bedford.
Update (1/14): I was wrong. The dew points dropped significantly this morning and temperatures fell along with them, hitting 14F in Natick and 9F in Bedford.