The coldest day of the year has not been recorded in many areas, according to historical data from the National Oceanic and Atmospheric Administration.
NOAA’s National Climatic Data Center has created a new “Coldest Day of the Year” map. The map is derived from the 1981–2010 U.S. Climate “Normals” – 30-year averages of climate conditions from weather station data across the country, including the average low temperature for each day.
From these values, scientists can identify which day of the year, on average, has the lowest minimum temperature, a.k.a. the “coldest day.”
The coldest day of the year can be as late as March or as early as Dec. 1 for areas of the contiguous U.S.
Historically, the western half of the Lower 48 has its coldest day in December, near the beginning of winter. In contrast, most eastern locations have their coldest day in January.
Areas that average the most snow cover, such as the Northeast and high-altitude regions in the West, tend to reach their climatological coldest day much later in the winter, likely because snow reflects much more sunlight than bare ground, NOAA says.
Other conditions being equal, the more sunlight the ground reflects, the less solar heating the location experiences.Normals for temperature are important indicators used in forecasting and monitoring by many U.S. economic sectors, NOAA says. Knowing the timing and probability of the year’s lowest temperatures can help energy companies prepare for rising heating demand.
Temperature Normals are also useful planning tools for the healthcare, construction, and tourism industries.
According to the NOAA the coldest days of the year for our area are usually in late December/early January.
