Iowa · live outlook · refreshes every 3 h

Iowa sap flow forecast

The next several days for Iowa's sugaring country, read the way a sugarmaker reads them: how cold the night gets, how warm the afternoon gets, and whether that adds up to a run.

Iowa highlighted on a map of the maple belt, with its forecast town (Decorah) marked — Iowa in the maple beltDots: Decorah

Season opens: mid-to-late February; typical
Closes: March, once buds begin to break; typical

Decorah · ISU says Iowa's commercial producers are in the northeast; Chickasaw, Winneshiek and Fayette counties report 29% of Iowa's taps, and Winneshiek County (Decorah) the most syrup (2022 Census of Agriculture).

Forecast for Decorah

Updated Nov 10, 6:16 AM EST

3 sap days in the next 6

freeze thaw 32°F

WedNov 11
42° / 52°
0h below · 24h above
No refreeze forecast
Low of 42°F — no refreeze is forecast. An earlier run may continue, then slow; temperature alone cannot rule out flow.
ThuNov 12
32° / 43°
1h below · 21h above
No refreeze forecast
Low of 32°F — no refreeze is forecast. An earlier run may continue, then slow; temperature alone cannot rule out flow.
FriNov 13
25° / 41°
15h below · 9h above
Classic sap day
Low 25°F, high 41°F — nights in the 20s and days in the 40s: the textbook sap day.
SatNov 14
22° / 45°
12h below · 10h above
Classic sap day
Low 22°F, high 45°F — nights in the 20s and days in the 40s: the textbook sap day.
SunNov 15
28° / 48°
8h below · 16h above
Classic sap day
Low 28°F, high 48°F — nights in the 20s and days in the 40s: the textbook sap day.
MonNov 16
35° / 52°
Run tapering
No overnight freeze (low 35°F). Yesterday's favorable weather may allow a run to continue, then slow without a refreeze.

Data: National Weather Service. Verdicts use freeze-thaw thresholds from maple field research; your woods may run a little differently.

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Hourly temperatures for your exact spot, turned into a day-by-day sap-run outlook. US and Canada.

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Data & method · 4

1.National Weather Service API · NOAA National Weather Service
2.Sap flow in sugar maple: timing and weather drivers (Frontiers in Agronomy, 2025) · de Lima Santos et al.
3.Maple Sugaring Tips for Beginners and Backyard Maple Sugar Producers · UNH Extension
4.North American Maple Syrup Producers Manual, 2nd ed. (Bulletin 856) · The Ohio State University Extension

LuckySap · free on iPhone & Android

Never miss the first run

LuckySap can ping you the evening before a strong sap day, then keeps your collections, sugar readings and boils in one season log. Free on iPhone and Android.