Merrimack River
River in New Hampshire, read from 2 USGS gauges, draining about 3,092 square miles. Figures refresh every fifteen minutes.
Discharge
504
cfs · 18 min ago
Normal for today
1,990
cfs median, 89 yrs
Water temp
—
not measured here
Gage height
2.35
ft
Gauges on this water
Reading by reach
Reading the number
On this date the gauge has averaged 1,990 cfs over 89 years of record, with the middle half of years falling between 1,280 and 3,060 cfs. Today is below that band: lower, clearer and, in summer, warmer water than a typical October day here.
Regional hatch calendar
What is likely hatching near Merrimack River
Merrimack River does not have its own verified chart yet. This calendar is combined from the verified charts on Saco River (48 mi), Millers River (69 mi), Lamoille River (97 mi). Treat it as regional timing, and file a report if you see something different here.
| Insect | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Blue-Winged Olive | January: absent | February: absent | March: absent | April: peak | May: active | June: absent | July: active | August: active | September: peak | October: peak | November: active | December: absent |
| Caddis | January: absent | February: absent | March: absent | April: active | May: peak | June: peak | July: active | August: active | September: peak | October: active | November: absent | December: absent |
| Golden Stonefly | January: absent | February: absent | March: absent | April: absent | May: active | June: peak | July: peak | August: active | September: absent | October: absent | November: absent | December: absent |
| Hendrickson | January: absent | February: absent | March: absent | April: active | May: peak | June: active | July: absent | August: absent | September: absent | October: absent | November: absent | December: absent |
| Brown Drake | January: absent | February: absent | March: absent | April: absent | May: active | June: peak | July: active | August: absent | September: absent | October: absent | November: absent | December: absent |
| Light Cahill | January: absent | February: absent | March: absent | April: absent | May: absent | June: peak | July: active | August: active | September: active | October: absent | November: absent | December: absent |
| Sulphur | January: absent | February: absent | March: absent | April: absent | May: peak | June: peak | July: active | August: absent | September: absent | October: absent | November: absent | December: absent |
| Terrestrials | January: absent | February: absent | March: absent | April: absent | May: absent | June: absent | July: peak | August: peak | September: peak | October: active | November: absent | December: absent |
| Trico | January: absent | February: absent | March: absent | April: absent | May: absent | June: absent | July: peak | August: peak | September: active | October: absent | November: absent | December: absent |
| Gray Drake | January: absent | February: absent | March: absent | April: absent | May: active | June: peak | July: active | August: absent | September: absent | October: absent | November: absent | December: absent |
| Green Drake | January: absent | February: absent | March: absent | April: absent | May: absent | June: peak | July: absent | August: absent | September: absent | October: absent | November: absent | December: absent |
| Hex | January: absent | February: absent | March: absent | April: absent | May: absent | June: peak | July: active | August: absent | September: absent | October: absent | November: absent | December: absent |
Reports
From anglers on Merrimack River
No reports filed here yet. The first one becomes the page’s local knowledge, stamped with the flow at the time. File a report.