One of the main methods used to calculate drought indices is called the Palmer Drought Severity Index (PDSI), which was developed in the 1960's and uses temperature and rainfall information in a formula to determine dryness.  The PDSI is most useful in determining long-term drought information and is expressed using negative numbers.  The scale for the PDSI is as follows: 0 = Normal Conditions, -2 = Moderate Drought, -3 = Severe Drought, -4 = Extreme Drought.  The PDSI is an acceptable calculator, because it is standardized for local conditions, thus making it applicable to any part of the country.  Below are links to the National Drought Integrated Drought Information System, National Climatic Data Center (NCDC) Indicator Maps for Drought Monitor and Soil Information, and the National Drought Mitigation Center.


National Integrated Drought Information System

U.S. and North American Drought Monitors

National Drought Mitigation Center

MD Hydrological Indicators

MD Regional Drought Status

Contact

The Maryland State Climatologist Office welcomes data requests and any questions or concerns you may have about our services.  You may contact us 24 hours a day, 7 days a week via telephone or e-mail.  If we are not in the office at the time of your call, we will get back to you as soon as we can.  Please contact us using the information below, or fill out our Data Request Form by clicking on the 'Data' link under the 'Climate Data' heading.  Thank you for letting us assist you in collecting climate data.

Whenever possible, please use email as it is the prefered method of communication to our office. It also allows us to have a record of data requests.

Phone: (301) 405-7223
E-Mail: climate@atmos.umd.edu

Click here for directions to our office.