Thursday, January 13, 2011

Utah 2010 Temperatures in Review

As discussed in yesterday's post examining global temperatures, the National Climatic Data Center has released its preliminary year-to-date global, national, and statewide climate summary for 2010.

If you thought this was a relatively cool year in Utah, you are right, but only in terms of the recent climate.  The statewide average temperature for Utah in 2010 was 48.9F.  This makes it the second coolest year (after 2009) since 1993, so it certainly seemed cool for recent Utah transplants or native Utahns who are short in the tooth.  Those with a longer memory might have a different perspective as 2010 was still a full degree warmer than the long term average for the 20th century (47.9F).

In fact, Utah has not had a year with an average temperature below the 20th century mean since 1993.  There are ups and downs from year to year, but the dice are loaded for warmer years.

One thing I would like to see done with the Utah temperature records is an analysis of how persistent wintertime cold pools in valleys and basins affect the long-term tend and year-to-year variability.  This could include an analysis of the frequency and intensity of those cold pools.  I suspect one would find differences between in valley/basin locations where these cold pools are common, and mountain locations where these cold pools are infrequent.


  1. What do you think about the impact of urban heat island effects and instrument siting problems, especially here in Utah where there are rapidly growing urban areas? I have read some fairly interesting reports in the last couple of years ( is an example) that claim to document some of these problems. I am just curious to see what others think about this.

  2. Dealing with the urban heat island is an important concern for groups working to determine temperature trends in the instrumented period.

    The best comprehensive description of the processing techniques used to create temperature trends from the instrumented period is probably Hansen et al. (2010). Available at, it includes a description of urban adjustments in section 4. Have a look.

    The processing used by NCDC for the time series presented in this blog post is described at See the section on urbanization effects.

  3. I suppose a simple but interesting analysis wold be to simply use ridgetop (or 700mb) temps to get an idea of what valley temperatures might look like sans cold pools and in a mixed atmosphere. SLC sure would be a very different place without the pooling.