Product Highlight: How to Find Past Weather Data

August 2005 Quality Controlled Local Climatological Data form for Mobile, Alabama

This August 2005 Quality Controlled Local Climatological Data form for Mobile, Alabama, shows wind speeds over 80 mph on August 29 during Hurricane Katrina.

Are you looking for past weather data at a specific location or on a specific date? NCDC has a variety of resources that can help you find just what you’re looking for. One way to access NCDC land-based data is through the Climate Data Online (CDO) application, which includes annual, monthly, and daily climate summaries;  radar data; annual, monthly, daily, and hourly climate Normals; and 15-minute and hourly precipitation data.

Using CDO, you can search for the data you need by browsing through these different datasets, by using the search tool, or by using an interactive map. If you’re looking for data from a specific dataset or more information on which dataset to choose, the CDO Dataset Discovery tool provides descriptions, documentation, and samples for a variety of NCDC’s past weather and climate datasets. Using the CDO Data Search method, you can enter search terms such as station name, city, state, zip code, country, and more. Using the Interactive Map Application, you can search for all of these same data via a GIS-based map application.

One specific dataset available through CDO is the Global Historical Climatology Network–Daily (GHCN-D) dataset. The GHCN-D dataset is an integrated database of daily climate summaries from land surface stations across the globe that have been subjected to a common suite of quality assurance reviews. Some of these data are more than 175 years old, while others are only a day old. The GHCN-D dataset includes not only data for the big cities but also for smaller towns and even rural areas, providing information on many more locations than some of NCDC’s other datasets.

Another option that provides hourly temperatures and precipitation amounts in additional to daily values, is the Quality Controlled Local Climatological Data (QCLCD) Product. QCLCD consists of hourly, daily, and monthly summaries for approximately 1,600 U.S. locations. This includes, for example, high and low temperatures, degree days, precipitation amounts, and winds. However, daily summary forms are not available for all of the stations. QCLCD begins with data for January 1, 2005 and continues to the present, and data prior to 2005 will be added to the product in the near future. It is updated daily, so the lag time is typically one day for the most recent data. 

For more information on all of the land-based datasets and products NCDC offers, see the Land-Based Station Data page.