Storm Events Database

The database currently contains data from January 1950 to February 2025, as entered by NOAA's National Weather Service (NWS). Due to changes in the data collection and processing procedures over time, there are unique periods of record available depending on the event type. The following timelines show the different time spans for each period of unique data collection and processing procedures. Select below for detailed descriptions of each data collection type.


Collection Source: (see below for descriptions) Collection Source:
The data collection methods have changed substantially over time. Prior to 1993, the records are extracted from the manually typed Storm Data Publication. From 1993 to the present the Storm Data Publication was built from the digital records in the database.

1. NWS Storm Prediction Center (SPC) Product (keyed from Publication): The SPC keyed data from the Storm Data publication into a csv/text file for Tornadoes (1950-1992), Thunderstorm Winds (1955-1992) and Hail (1955-1992). Once the Storm Events Database was created in 1996/1997, these data were imported. The SPC converted all records into Central Standard Time (CST) and care must be taken when using these records.

2. Unformatted Text Files: From 1993-1995, the NWS Weather Offices sent their keyed Storm Data files to directly to NCEI in Word Perfect 5.0 format on 3.5" floppy diskettes. These files were merged for inclusion into the Storm Data publication. A best effort was made to import these files into the original Storm Events Database in FoxPro 3.0 format. (June & July 1993 were misplaced and are not included) These data had many inconsistencies in the spelling of event types and were standardized into the 48 current event types at NCEI in 2013.

3. Paradox Database Files: Beginning in January 1996, the NWS began using Storm Data for forecast verification purposes and the NWS decided to collect the data at the NWS Headquarters in Silver Spring, MD. They selected Borland/Corel Paradox format for their database and supplied the NCEI with the raw data files, which were then used for the Storm Data publication and inclusion into the Storm Events Database. From 1996-1999, the event type field was a free-text field so there were many, many variations of event types. Most of the events were standardized into the 48 current event types in 2013. In 2000 the NWS added a drop-down selector for Event Type on the data entry interface, which standardized the Event Type values sent to NCEI.

4. Comma-Separated Text (CSV) Files: In October 2006, the NWS switched from Paradox to Windows SQL Server and it was decided that the NWS would supply NCEI with comma separated (CSV) text files that NCEI would import into their own database for the Storm Data publication and Storm Events Database.