Gauge Description:

Visual Gage just upstream of Gilsum Gorge, on the river-right retaining wall, according to the 18-year-old AMC River Guide. 3.5 is minimum; 5.5 is high.
This section of the Ashuelot lies above the Surry mountain flood control dam and therefore is a natural flow river. 
A new USGS gauge is located atr the same location as the visual gage on river right of the stone arch bridge entrance to Gilsum gorge accessed from NH route 10.
 

Estimated chance (%) of finding the river runnable.
 

Month............% chance.................comment 

January ............ 0%....frozen. 
February.............0%....frozen
March................20%....Usually frozen. 
April...............70%....Best chance 
May ................25%....Best chance in early May with rain. 
June.................8%
July.................5% 
August...............5%....Just a trickle
September...........10%....Tropical storms and their remains 
October........…....20%
November............35%....Fall rains, dormant trees 
December............30%....River starts freezing about Christmas. 

Be aware this is averaged out over several years. The % chance refers to the probability of finding the river running on any given day. For instance a 5% probability for August means on average you can only expect 1-1/2 days of water. One year there could be 3 days in August with water, other years none. Spring levels are usually higher than fall levels.