Maple sap run estimator

Know when
the woods will run.

Research-guided sap-flow forecasts tuned to your local weather and collection setup.

7-day outlook

Canaan, New Hampshire

Run potential · Forecast

100/100

Excellent

Prime collection day

Plan to collect. The freeze–thaw cycle should create useful stem pressure.

Tune the scenario

Temperatures & conditions

Overnight low°FBelow 32°F creates suction and replenishes the tree.Daytime high°FA gradual thaw into the upper 30s or low 40s is strongest.

Cloud cover%Peak wind mph

Tubing under vacuumImproves collection; it does not create the freeze–thaw cycle.

What drives today’s score

Read the trees.

Nighttime recharge

Deep enough to recharge

26°F forecast low. The score rewards a genuine overnight freeze.

Daytime pressure

Ideal gradual thaw

43°F forecast high. Thawing creates positive pressure in the tree.

Daily swing

17°F across freezing

The day crosses the key 32°F threshold.

Quality watch

Low spoilage pressure

32% cloud cover · 8 mph peak wind.

The science under the score

Built on the freeze–thaw mechanism, not folklore.

Freezing creates negative pressure that draws water into dormant maple trees. When the wood thaws, pressure turns positive and sap exits the taphole. Because trunks and branches lag the air, a fleeting dip below 32°F is less reliable than a sustained freeze.

Cornell Maple Program field guide ↗UVM Proctor Maple Research Center ↗