Major Update of Local U.S. Climate Data Due by June 30

June 8, 2011

As it does near the beginning of every decade, NOAA's National Climatic Data Center is updating its data for 30-year averages (called "normals") for a range of climate indicators such as temperature and precipitation. The most widely used normals for the period 1981-2010 (including temperature, precipitation, snowfall, snow depth, and heating and cooling degree days) are scheduled to be released at the end of June 2011. The remaining data are scheduled for release by the end of 2011.

Meteorologists often use these 30-year averages as one practical definition of "climate." They even out the variability of shorter-term "weather" — but they also remind us that climate can and does change. They are only one of the many time-scales on which climate change can be measured.

There will be temperature data for about 6,000 stations and precipitation data for about 8,000. For 200-300 stations, there will also be data on dew point temperature, sea-level, pressure, and wind.

Replacing the 1970s data with that for 2001-2010 — a decade that has generally been the warmest ever recorded in the US — will result in warmer normal temperatures in many locations, though some will be cooler, at least for certain seasons. Precipitation changes have been highly variable.

In advance of the release of the new data, you might want to download the information for 1971-2000 for any locations you're interested in, so you can get a sense of what types of climate topics can be covered, and to give you data to compare to the new normals. Of all the links provided on the pages above, one starting point is:

Much more climate data is available at:

When reporting on any changes in the stations you're investigating, make sure to check whether there have been any adjustments in the location of monitors or other factors that may contribute to any shifts. NCDC is attempting to account for changes in methodology or technology, but you'll need to know what changes have occurred in order to report accurately.

Overall, this new data will allow you to cover climate change on a local, regional, and national scale from many perspectives. Along with presentation and analysis of the basic data, you can report on the perspective of many people and organizations who use this data, such as utility companies, farmers, engineers, contractors, building designers, landscape architects, planning commissions, public health officials, and many others.