How Much Rain is Enough to Offset Drought?

While some areas of the Corn Belt received much-needed rain this week, the U.S. Drought Monitor still shows expanding drought conditions.

Map produced by the National Drought Mitigation Center

So how much rain is genuinely needed to alleviate drought conditions? The National Drought Mitigation Center (NDMC) says the answer isn’t so simple. Precipitation, streamflow, reservoir levels, temperatures and evaporative demand, soil moisture, vegetation health and other factors all contribute to custom answers for different parts of the country.

Simply put, looking at the forecast isn’t enough to truly predict drought mitigation. Additionally, collecting data over time is just as important as monitoring all of the above categories. Transitioning from no drought to D2 is very different from transitioning from D2 to D4. And when it comes down to it, the evolution of drought in the growing season is ultimately the indicator of crop condition, something that can’t be indicated on a map.