From the Spaceflight Meteorology Group:

The National Weather Service has issued a Cold Weather Advisory that includes JSC beginning midnight tonight through 10AM Thursday morning. Combination of cold temperatures and brisk winds will send the wind chill index into the upper teens overnight. JSC is forecast to set a record low temperature on Thursday of 30° and quite probably a record for coldest maximum temperature as well with a high in the mid 40s tomorrow. Temperatures below freezing are forecast beginning around 3AM lasting until near 9AM tomorrow.