When Is The Coldest Day Of The Year In Rocky Mountains?

coldest day

Brrrr. It’s cold outside.

The coldest day of the year on average in the Rocky Mountains tend to be in late December.  Here is when the average coldest times take place for a few different cities in the Rockies.

This winter has been very cold.  These cold temperatures got me wondering about when are the average coldest days of the year in the Rocky Mountains.  The Rockies are full of some big cities and many areas that are very high in elevation.  This means those coldest times differ for the different locations.  Here is the thirty year average for when those coldest times of the year take place.

coldest day Data Based Comes From NOAA (National Oceanographic and Atmospheric Administration)

The information that I am basing my sharing of the coldest day and month of the year comes from NOAA, specifically from their National Center for Environmental Information.  NOAA collected data and then analyzed the coldest times of year based on the temperatures from 1981 – 2010.  That is 30 years of data and the average dates and times may be changing in recent years, but this is based on that 30 year period.

coldest day of year

Days of the Lower 48’s coldest low temperatures during an average year, using 1981-2010 averages. Map from NOAA NCEI

Coldest Day Of The Year

Well, interesting it turns out that the coldest day of the year comes earlier to the west coast and then slowly moves across the USA towards the east coast.  The Rocky Mountain states tend to experience the coldest day of the year in late December or early January (in the big cities).

Salt Lake City has its coldest day of the year between January 9 and 22nd.

Denver has its coldest day of the year between December 15 – 30.

Billings experiences its coldest day of the year between December 23 and 31.

For comparison purposes, Seattle has its coldest day of the year December 18 and Chicago January 19 – 20.

Of course, higher elevation areas in the Rockies have their coldest day of the year later in the year, more towards the middle to end of January.