An interactive data tool exploring how the changing definition of a climate normal affects our interpretation of projected future average precipitation.
Longest Stretch of Dry Days
Longest Annual Stretch of Dry Days
This tool is excerpted from Mid-Atlantic Regional Climate Impacts Summary and Outlook: Fall 2022.
While the focus of water management in the Mid-Atlantic is often on extreme high precipitation, drought can and does occur. In the late 1990s, for example, drought across the region led to major crop losses and declarations of emergency for 11 localities in Virginia. States also imposed restrictions on water users as water supplies lowered.1 Other past droughts in the region, such as in 2002, have also produced losses in crop production, and some have co-occurred with heat waves, resulting in impacts to human health and fatalities.
As of December 1, parts of central Virginia are designated as abnormally dry. In fact, most states in the Mid-Atlantic regularly experience abnormally dry conditions. Since 2005, Pennsylvania, Virginia and Maryland have all seen abnormal dryness for at least part of the year.2 The number of consecutive days without precipitation can show when drought may be forming or if an area may experience abnormal dryness into the future. Even short duration periods of dryness could exacerbate drought conditions. Severe and extreme drought conditions in the region can last as short as days or weeks and up to months, though very rarely years.
The following data tool presents an analysis of historical and projected consecutive dry days. The key findings from this tool are presented below.
- The Mid-Atlantic region is projected to experience a similar number of consecutive dry days in the future under the low emissions scenario.
- Under the high emissions scenario, a few areas will experience small increases in the number of consecutive dry days, particularly northern Maryland and southern Pennsylvania.
- By the end of the century, the Mid-Atlantic region could see 22.9 days of less than 0.1 inches of precipitation in a row per year in a high emissions future, compared to an historical average of 21.6.