Editor’s Note: This piece was written by meteorologist Matthew Moll of New England Weather Consulting, who has prepared an Arlington-specific forecast for YourArlington since 2024.
After a wetter stretch of weather in July, it is reasonable to ask a simple question: Is Arlington really still in a drought?
The answer is yes, although conditions have improved considerably from where they were earlier this year. Northeastern Massachusetts, including Arlington, remains in drought. That illustrates an important point about drought: it cannot be measured simply by adding up how much rain has fallen over a few weeks.
That can be confusing when rainfall totals vary so dramatically across Massachusetts. One location may be running several inches above normal while another is below normal. Even within eastern Massachusetts, thunderstorms and summer downpours can produce large differences over relatively short distances.
We saw a good example of that around Arlington in July. During one rain event on July 6 and 7, a Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) observer in Arlington recorded only 0.03 inch of rain, while observers in nearby Lexington received around three-tenths of an inch. CoCoRaHS, is a nationwide network of trained volunteers who measure and report precipitation using standardized rain gauges. That is roughly ten times as much rain over a distance of only a few miles, showing why rainfall totals from Worcester, Boston, or even a neighboring community do not necessarily tell us what happened in Arlington.
More importantly, drought develops over months rather than days. Massachusetts entered the summer carrying the effects of an extended period of below-normal precipitation. A wet week, or even a wet month, can improve lawns, gardens, streams and the upper layers of soil relatively quickly, but it takes considerably longer to replenish groundwater.
July certainly helped. It was a much wetter month across the region, and rivers, streams and soil moisture responded. But now August has turned dry again. That matters because drought recovery requires sustained precipitation over time, not simply one wet month sandwiched between longer dry periods. July helped us make up some ground, but the return to dry weather in August means we are not out of the woods.
Groundwater responds particularly slowly. Water has to soak through layers of soil and rock before reaching the aquifers that help sustain wells, wetlands and streams during dry periods. After a prolonged drought, those deeper reserves cannot be restored by a few heavy rainstorms.
That is why looking at a rainfall departure such as “one inch below normal” does not, by itself, tell us whether Arlington is experiencing drought. Drought assessments consider precipitation over different time periods along with groundwater, streamflow, soil moisture and other indicators.
I saw a good example of just how deceptive surface moisture can be in my own yard recently. After planting, I watered what I thought was quite heavily, enough that the ground certainly looked puddles and very wet. But when I dug down just an inch or so, I was surprised to find the soil was still bone dry. When soil becomes extremely dry, it can become temporarily hydrophobic, meaning it actually repels water rather than readily absorbing it. Water may run off or remain near the surface, leaving the soil surprisingly dry just below.
There is also a difference between getting a lot of rain and getting the kind of rain that is most helpful for drought recovery. A torrential summer thunderstorm may drop an inch of water in a short period, but some of that water runs into storm drains and streams rather than soaking deeply into the ground. Several slower, widespread rain events spread over a number of weeks would be much more beneficial for longer-term recovery.
For Arlington, the practical takeaway is that July was a welcome improvement, but it did not erase the longer-term drought, and the renewed dry weather in August is something to watch. The town’s reminders to water young street trees still make sense. Trees and other vegetation can experience stress from dry soil even while some of the broader drought indicators have improved.
What we need now is not necessarily one huge rainstorm, but a sustained return to regular rainfall. July showed how quickly some conditions can improve when the rain returns. August is also reminding us how quickly the ground can begin drying out again.
This explanatory story was published on Aug. 12, 2026.
