At Nov 9, 7:12 a.m. EST the NOAA gauges read 176.36 m at De Tour Village (north end) and 176.51 m at Harbor Beach (southwest shore), in metres above IGLD 1985. The southwest shore is 15 cm higher: wind is piling water against that shore. Averaged over 2026-11-08, the two gauges stood 3 cm below the November long-term average of 176.41 m.
De Tour Village at the north end, where the St. Marys River comes in, and Harbor Beach on the southwest shore. Georgian Bay has no NOAA gauge; it shares the lake’s level, give or take short-lived wind effects. Six-minute readings from NOAA, preliminary until NOAA verifies them; times in Ontario time.
The mean of each full day at each gauge, worked out on this site from NOAA’s six-minute readings, against the November long-term average (1918–2025).
Gauges on the US shore, run by NOAA. Harbor Beach is NOAA GLERL’s master gauge for Michigan-Huron; Mackinaw City marks the Straits of Mackinac, where Lake Michigan and Lake Huron meet.
| Gauge | Where | Latest (m, IGLD 1985) | 24 h | Reading time |
|---|---|---|---|---|
| De Tour Village (9075099) | north end | 176.358 | −0.05 m | Nov 9, 7:12 a.m. EST |
| Harbor Beach (9075014) | southwest shore | 176.511 | +0.11 m | Nov 9, 7:12 a.m. EST |
| Mackinaw City (9075080) | Straits of Mackinac | 176.309 | −0.10 m | Nov 9, 7:12 a.m. EST |
The gauges on the Canadian shore and in Georgian Bay are run by the Canadian Hydrographic Service of Fisheries and Oceans Canada; we link to their pages rather than reproduce their data: Point Edward, Goderich, Tobermory, Collingwood, Midland, Parry Sound, Little Current, Thessalon.
Lake-wide monthly means for Michigan-Huron, 1918–2025, from the coordinated Canada–US series published by NOAA’s Great Lakes Environmental Research Laboratory (GLERL). The averages and records are worked out on this site from that series. Levels in metres above IGLD 1985.
| Month | Long-term average (m) | Record high (m) | Record low (m) |
|---|---|---|---|
| January | 176.32 | 177.26 (2020) | 175.57 (2013) |
| February | 176.31 | 177.25 (2020) | 175.59 (1964) |
| March | 176.32 | 177.22 (2020) | 175.58 (1964) |
| April | 176.41 | 177.30 (2020) | 175.61 (1964) |
| May | 176.51 | 177.38 (2020) | 175.74 (1964) |
| June | 176.57 | 177.45 (2020) | 175.76 (1964) |
| July | 176.60 | 177.45 (2020) | 175.78 (1964) |
| August | 176.58 | 177.42 (2020) | 175.77 (1964) |
| September | 176.53 | 177.38 (1986) | 175.76 (1964) |
| October | 176.46 | 177.50 (1986) | 175.70 (1964) |
| November (now) | 176.41 | 177.38 (1986) | 175.65 (1964) |
| December | 176.36 | 177.26 (1986) | 175.61 (2012) |
Highest monthly mean on record: 177.50 m, October 1986. Lowest: 175.57 m, January 2013, 43 cm below chart datum. Chart datum is 176.00 m.
NOAA GLERL’s coordinated lake-wide series gives Michigan-Huron a provisional mean of 176.53 m for September 2026, level with the September average for 1918–2025 and 18 cm above September 2025 (176.35 m). The International Lake Superior Board of Control (3 September 2026) reported that at the start of September Michigan-Huron was 2 cm above its seasonal long-term average (1918–2025) and 16 cm above a year earlier, after falling 5 cm in August against a typical 4 cm. For September the board expected a fall of about 6 cm under average conditions, a 1 cm rise if much wetter and a 12 cm drop if much drier.
The coordinated six-month forecast range, prepared by Environment and Climate Change Canada and the US Army Corps of Engineers and published on NOAA GLERL’s Great Lakes Dashboard, puts the October 2026 lake-wide mean between 176.40 and 176.56 m, against an October average of 176.46 m, and February 2027 between 176.10 and 176.50 m, against a February average of 176.31 m.
Hydraulically, Lake Huron and Lake Michigan are one body of water. The Canadian Hydrographic Service (CHS) explains that they are joined by the broad, deep Straits of Mackinac and are treated as a single lake, with a common chart datum of 176.00 m. Georgian Bay and the North Channel are part of Lake Huron, so they share the same lake-wide level; local differences come from wind and pressure, not from a separate supply. The official lake-wide average is calculated from Ludington, Mackinaw City, Harbor Beach and Milwaukee on the U.S. shore and Thessalon and Tobermory on the Canadian shore, and NOAA GLERL lists Harbor Beach as the master gauge. Monthly bulletins label the lake either ‘Lake Huron’ or ‘Michigan-Huron’; the numbers are the same.
Levels are given in metres above the International Great Lakes Datum of 1985 (IGLD 1985), the common Canada–U.S. height reference. According to the CHS, its zero sits at mean water level at Rimouski, Quebec, and it has been in use since January 1992. Chart datum, also called Low Water Datum, is 176.00 m for Michigan-Huron, and NOAA defines it as the surface from which depths on charts are measured. Subtract 176.00 from a reading to get the water standing above charted depth. NOAA expects to replace IGLD 1985 with IGLD (2020), tentatively in 2027, and chart datums may be reviewed at the same time. NOAA gauges record a three-minute average every six minutes.
Water arrives from Lake Superior through the St. Marys River, whose outflow has been regulated since 1921 (CHS). The International Lake Superior Board of Control sets that flow under Plan 2012, and the IJC order requires that Michigan-Huron levels be considered too, with the aim of keeping both lakes in a similar position within their historical ranges. The board adds that regulation cannot control precipitation, evaporation or runoff. Michigan-Huron drains through the St. Clair River, which falls 1.6 m to Lake St. Clair, and then the Detroit River to Lake Erie. That outlet is not regulated; the IJC describes only Lake Superior’s and Lake Ontario’s outflows as regulated. The CHS says Michigan-Huron usually peaks in July and is lowest in February, with an average seasonal swing of about 0.4 m. An IJC fact sheet credits the Chicago diversion, the Long Lac–Ogoki diversions and the Welland Canal combined with lowering Michigan-Huron by only 0.6 cm.
Coordinated lake-wide monthly means start in 1918. For 1918–2025 the coordinated lake-wide series published by NOAA GLERL gives a highest monthly mean of 177.50 m (October 1986) and a lowest of 175.57 m (January 2013), a range of 1.93 m. Most monthly record lows date from 1964, with December 2012 and January 2013 setting the winter lows. Ontario’s Special Advisor on Flooding described a long run of below-average levels from 1999 to about 2013. Levels then rose quickly: every month from January to August has its record high in 2020, and the review notes that Lake Huron came within one centimetre of its record in July 2019.
Wind effects are smaller here than on Lake Erie, but they are real. The CHS explains that storm surges are largest at the ends of an elongated basin, especially when the long axis lines up with the wind, and that funnelling shorelines and gently sloping bottoms amplify the change. The same physics applies to the heads of bays such as Georgian Bay and Saginaw Bay. Pressure also matters: water stands lower under high pressure and higher under low pressure. We did not find an official Canadian figure for seiche height in Georgian Bay, so this page shows what the gauges record instead. The 72-hour chart pairs De Tour Village at the north end with Harbor Beach on the southwest shore, and their lines move apart when wind piles water toward one end.
Because charted depths are measured from chart datum, the lake’s position above or below 176.00 m changes the water over every shoal, launch and channel by the same amount. In August 2026 the lake averaged 176.60 m, or 0.60 m above datum. At the record low of January 2013 it stood at 175.57 m, 0.43 m below datum, which leaves 1.03 m less water than in August 2026 over the same charted spot. That difference matters around Georgian Bay’s rocky shoals and shallow harbours. In high-water years the risk turns to flooding and erosion. Conservation authorities regulate development along the Great Lakes shoreline and issue local flood messages, and Ontario’s flood message system includes ‘water safety’ statements for conditions that could be dangerous for boaters and anglers.
The Canadian Hydrographic Service runs the Canadian gauges. Its station pages for Point Edward, Goderich, Tobermory, Collingwood, Midland, Parry Sound, Little Current and Thessalon show recent readings, and Tobermory and Thessalon are part of the lake-wide average. The CHS Monthly Water Level Bulletin and six-month forecast cover the lake as ‘Lake Huron’. Each month the International Lake Superior Board of Control publishes an update giving Michigan-Huron’s position against the 1918–2025 average and a one-month outlook. We link to the CHS pages rather than reproduce their data.
The live values are the latest six-minute readings from NOAA’s De Tour Village and Harbor Beach gauges. If they differ by more than a few centimetres, wind or pressure is tilting the lake and neither one is the lake-wide level. The 72-hour chart shows that tilt. The 30-day chart of daily means shows the seasonal trend, which you can compare with the monthly average in the table. Recent NOAA readings are provisional and can be revised.
The live readings at the top come from NOAA’s De Tour Village and Harbor Beach gauges and update every six minutes, in metres above IGLD 1985. The latest lake-wide monthly figure is a provisional 176.53 m for September 2026, level with the September average for 1918–2025 (coordinated series published by NOAA GLERL). At the start of September the International Lake Superior Board of Control put Michigan-Huron 2 cm above average and 16 cm above a year earlier.
Georgian Bay is part of Lake Huron, so its level is the Lake Huron (Michigan-Huron) level shown here, give or take short-lived wind effects. For local readings, the Canadian Hydrographic Service has gauges at Collingwood, Midland, Parry Sound, Tobermory and Little Current; links are on this page.
Close to normal. The provisional September 2026 lake-wide mean equalled the September average and was 18 cm above September 2025. The coordinated forecast range published in September 2026 runs from 176.40 to 176.56 m for October, against an October average of 176.46 m, and from 176.10 to 176.50 m for February 2027.
They are joined by the Straits of Mackinac, which the Canadian Hydrographic Service describes as broad and deep, so they behave as one lake and share a chart datum of 176.00 m. Official bulletins report a single Michigan-Huron level.
The lowest lake-wide monthly mean since 1918 is 175.57 m in January 2013, 0.43 m below chart datum. The highest is 177.50 m in October 1986 (coordinated lake-wide series, 1918–2025).