That is the question, when do you tap. Usually you wait for the weather to get just about right, freezing at night above freezing durning the day. I live in the southern part of New Hampshire, but in the far west part of the state.
We tapped lasted weekend, that Saturday when it reached almost 50 degrees. Then wouldn't you know it turned cold. The trouble with tapping to early is the trees start to heal not long after you tap, so if you tap early and the sap run is late you loose. If you wait until the guy next door taps, he was waiting to see you tap, you may loose the first early run which is often the best quality.
This year it will be hard to tell, but we have the buckets out already. This past summer was dry and the fall was dry also, I am not looking for a good sugar season this year for those reasons. The weather needs to be right also, cold at night warm durning the day with no cold wind.
The sap flows up from the roots with the warm temps and the cold causes it to flow back down at night. The warmer the weather the quicker the buds form on the trees which makes the sap cloudly and starchy, not sweet. That is why the first runs are best.
Sap ran a little this last week, expect it to have run today some too. Sap will only keep so long when the weather gets warm so make sure you process it as soon as you can. I have had my own small sugar house for 20+ years, before that I helped a friend sugar for about 8 years.
Randy