Sapcast

See it in action — no location needed, no waiting for winter

← Back to the real forecast

It's August. There's no freeze-thaw happening anywhere right now, so if you opened the real forecast today it would just tell you every day is poor and leave it at that — true, but useless.

This page is what the real app looks like in the middle of a good week. The temperatures below are made up; the ratings, the recommendation, and the tap-by dates are not — they're the same scoring code that runs on sapcast.ca every morning during sugaring season, just fed a week I picked instead of one it fetched.

I built this after a few seasons of checking five different weather sites every morning and still guessing wrong. “-2°C” doesn't tell you anything by itself — what matters is whether last night froze hard, whether today actually thaws, and whether that keeps happening for more than a day. That's the only thing this tool computes.

Try a week

Best Tapping Window

Season Timing

7-Day Forecast

Aggregated from multiple weather models. Tap any day to see per-source details.

How It Works

The Freeze-Thaw Cycle

Maple sap flows when nighttime temperatures drop below freezing and daytime temperatures rise above freezing. This creates pressure changes inside the tree that push sap through the tap.

What the Ratings Mean

  • Excellent: Ideal freeze-thaw — overnight lows of -7°C to -2°C with daytime highs of 4°C to 10°C.
  • Good: Solid freeze-thaw cycle — freezes overnight, thaws above 2°C during the day.
  • Fair: Marginal — some freeze-thaw activity but temperatures are outside the ideal range.
  • Poor: No freeze-thaw cycle — either too warm (no freeze) or too cold (no thaw).

Consecutive Days Matter

The best sap runs happen during extended stretches of freeze-thaw days. A single good day produces less sap than a 5-day run. The "Best Tapping Window" highlights the longest stretch of good-or-better conditions in the forecast.

Tapping Guides

Choosing & Tapping a Tree

Pick a healthy sugar maple at least 30 cm (12 in) in diameter. Place the tap above a large root or below a large branch on the south-facing side for the earliest flow.

  • Tree size: 12–18 in diameter supports one tap; larger than 18 in can take two (Vermont Evaporator Co.).
  • Drill: Use a 5/16″ or 7/16″ bit, about 5 cm (2 in) deep at a slight upward angle.
  • Check your shavings: Light-coloured chips mean healthy sapwood — dark shavings mean pick a different spot (Tap My Trees).

Collecting & Boiling

Hang a food-safe, lidded bucket or attach tubing to the spile. Collect sap daily and refrigerate it — sap spoils quickly above freezing.

  • Ratio: It takes roughly 40 litres of sap to make 1 litre of syrup.
  • Boil outdoors: The steam will peel wallpaper indoors (Old Farmer's Almanac).

When to Pull Your Taps

Without the freeze-thaw cycle, sap flow stops. Watch for these signs that the season is over:

  • No more freezing nights: Once temperatures stay above freezing consistently, flow dries up (Mother Earth News).
  • Bud break: Once buds appear on the branches, sap develops an off "buddy" flavour that won't make good syrup. Pull your spiles before buds open.

End-of-Season Cleanup

Remove spiles with pliers and let tap holes heal on their own — don't plug them.

  • Clean equipment: Scrub with dilute bleach (1 part unscented bleach to 20 parts water), then triple-rinse with hot water (Tap My Trees).
  • Store dry: Keep spiles, buckets, and lids in a dry, dust-free place until next season (Vermont Evaporator Co.).