Merrimack stripers tracking the herring run as moon peaks

What's Biting

What's Next

The waxing gibbous moon crests toward full over the next 48 hours, which should sustain and possibly intensify feeding activity on the Merrimack. On The Water's striper migration tracking flags that the spring run hits its peaks around the moon and softens between cycles, putting late May 26 through early June squarely in the better portion of the calendar.

As long as the herring remain active in the system, bigger stripers should stay committed to the upper river stretches. If the run begins to thin, look for fish to stage near the mouth and lower estuary rather than pushing as far upstream. Paddletails on leadheads remain the most consistently mentioned presentation for the mouth zone, per The Fisherman — New England Freshwater; once you are into the river proper, working current seams with bucktails or soft plastics around visible bait concentrations is the more reliable play.

Flow at 225 cfs is moderate and favorable for wading and bank access on the upper Merrimack. Watch for any significant rain in the watershed over the next few days. A sustained rain event would push the gauge notably higher and likely cloud visibility, temporarily suppressing the bite. If conditions hold dry, a modest decline in flow is reasonable to expect as late-May runoff tapers, which should improve water clarity further and concentrate fish near visible structure.

On Lake Winnipesaukee, the post-spawn window for bass is likely opening up now. Late May through early June typically finds NH bass transitioning off beds and beginning to feed actively along rocky shorelines, laydowns, and drop-offs. Wired 2 Fish's breakdown of post-spawn bass behavior notes that some fish come off the bed highly aggressive while others stay shallow and spooky, which means both finesse and moving-bait approaches are worth having on deck. Landlocked salmon and lake trout are likely moving toward deeper, cooler water as the surface warms; early morning passes over open water and drop-offs are the more reliable approach for salmonid species going into June.

Plan your weekend outing around the dawn-to-mid-morning window for the best combination of low-light conditions, active bait movement, and feeding stripers on the Merrimack. Per The Fisherman — New England Freshwater, either side of low tide at the mouth has been the productive window for inside-river fish, and that timing pattern should hold through the weekend.

Context

Late May represents a reliable high point for Merrimack River striper fishing in New Hampshire. The herring run has historically been the trigger event, concentrating baitfish in the river and pulling migratory stripers well upstream. In strong years, 30-inch-plus fish are common inside the river during peak herring weeks; the 40-inch class reports coming from the Merrimack corridor in 2026 are consistent with what the system produces during a healthy run year. Based on reporting from The Fisherman — South Shore MA to ME, the run appears to still be at or near its peak heading into Memorial Day weekend. In some years the run begins to taper by mid-month; 2026 tracking at or past that benchmark gives anglers a longer-than-usual window if conditions hold.

For Lake Winnipesaukee, no direct comparison data from this cycle is available. Typical late-May patterns involve bass completing the spawn in shallower rocky bays and coves as water temperatures climb through the upper 50s into the low 60s Fahrenheit, with landlocked salmon and lake trout beginning their seasonal retreat toward deeper water as the thermocline establishes. These are Winnipesaukee's signature species and the seasonal calendar generally holds consistent year to year, though water temperature data was not available for this cycle to confirm precisely where the transition stands in 2026.

One context item worth noting for Merrimack anglers: On The Water reported in early May that two separate pairs of anglers were arrested for illegal fishing on the Merrimack River on May 8 and 9 at the same location, indicating active conservation officer presence on the river this season. Striped bass regulations have been subject to change in recent seasons across New England in response to regional stock assessments. Review current NH and MA rules on size limits, gear types, and any restricted zones near herring runs before heading out.