Drought in Merrimack, New Hampshire

The USDM on April 28 had 59% of Merrimack County in Severe Drought (D2), and by the end of May severe drought slightly eased to 56%, with 44% in Moderate Drought (D1). May rainfall averaged 5.99 inches, well above normal by 2.46'. However, one wet May wasn't enough to wipe out extended long-term shortfalls: the 12-month period ending May with a multi-month precipitation deficit of more than 6 inches.

In May 2026, New Hampshire saw noticeable short-term improvements in drought conditions, though deep groundwater deficits continued to pose a challenge across the state. Soaking rains in mid-May provided widespread relief, particularly across the northern mountains and foothills. Over a single week ending May 19, the coverage of Severe Drought (D2) in New Hampshire dropped significantly from 36% down to 20.5%. The mid-May rain events successfully replenished surface topsoil moisture, restored streamflows, and boosted lake and reservoir levels back toward seasonal baselines. However, extended precipitation deficits over the preceding 90 days, particularly across southern New Hampshire, kept deeper hydrologic systems under stress. Deep groundwater aquifers respond on a much slower, lagging timeframe, meaning the water table remained significantly lower than long-term historical averages for May. Consequently, several groundwater monitoring wells across southern and central New Hampshire continued to record below to much-below normal levels.