Birch Season for 1 Tap.

Here are a few plots showing how birch sap flows throughout the season. In general, birch trees run much later than maple trees, and when the temperature is above freezing, it seems to constantly run without requiring constant freeze-thaw cycles.

Temperature, sap, and flow rate for 1-tap over 1-day.
Temperature, sap, and flow rate for 1-tap over 7-days.
Temperature and sap for 1-tap over the entire season.
Temperature and sugar content every day the sap was running.