Mary Lake at Port Sydney water level

Name: Mary Lake at Port Sydney water level (Environment and Climate Change Canada – Water Survey of Canada)
Creator: Environment and Climate Change Canada – Water Survey of Canada
License: https://open.canada.ca/en/open-government-licence-canada

Lake, Mary Lake, Ontario, Canada

Directions

Normal for mid-October

Water level

8.47m Steady over the last 24 hours

Measured Oct 20, 2026, 03:45 PM EDT (2 hours ago)

History

7 days 30 days 10 years Years compared

202020212022202320242026

Water level Normal range (10–90 %)

What this means

Mary Lake at Port Sydney is at 8.47 m, in the normal range for mid-October.

That puts it 0.02 m below the median of 8.49 m for mid-October, based on 11 years of readings.

The level has held steady over the past 24 hours. In the last month it has stayed between 8.47 m and 8.63 m.

Lakes and reservoirs often sit lower in fall after a summer of evaporation and use, and recover with winter rain and spring snowmelt.

Compared with 11 years of daily readings for this time of year. How to read levels

Key numbers

Median for this date: 8.49 m0.02 m below the median for this date
Normal for this date: 8.44 m – 8.55 m8 years in 10 fall in this range (11 years of records)
Lowest and highest in 30 days: 8.47 m – 8.63 m
Lowest and highest in 12 months: 8.47 m – 8.67 m

On the water at Mary Lake at Port Sydney

Normal levels mean few surprises on the water: ramps in use and the shoreline where you expect it.

Wear a life jacket on the water. Most boating deaths involve people who were not wearing one.

Weather at the gauge

No rain in the last 3 days.

20 Tue 15° -1° – Wind 7 km/h

21 Wed 14° 1° – Wind 10 km/h

22 Thu 15° 4° – Wind 13 km/h

23 Fri 13° 2° – Wind 8 km/h

24 Sat 15° 3° – Wind 11 km/h

25 Sun 18° 7° – Wind 17 km/h

26 Mon 12° 3° 2.1 mm Wind 11 km/h

Forecast: Open-Meteo

Sunrise 07:40 AM Sunset 06:25 PM Daylight 10 hr, 45 min Waxing gibbous 71%

Map

Nearby gauges

Gauge	Level	Compared with normal	24 hours	Distance
North Branch Muskoka River at Port SydneyRiver gauge, North Branch Muskoka River	0.78 m	Low	+0.01 m	0.8 km
Fairy Lake at HuntsvilleLake, Fairy Lake	6.27 m	Normal	±0	13 km
Lake of Bays at BaysvilleLake, Lake of Bays	10.22 m	Normal	+0.01 m	15 km
South Branch Muskoka River at BaysvilleRiver gauge, South Branch Muskoka River	7.43 m	Very low	±0	15 km
Big East River near HuntsvilleRiver gauge, Big East River	5.18 m	Very low	−0.02 m	21 km
Lake Muskoka at BeaumarisLake, Lake Muskoka	9.33 m	Normal	±0	24 km
Oxtongue River near DwightRiver gauge, Oxtongue River	3.05 m	Low	+0.02 m	25 km
Lake Rosseau at Port CarlingLake, Lake Rosseau	8.79 m	Low	±0	26 km

Questions and answers

What is a normal level for Mary Lake at Port Sydney in mid-October?

The median for mid-October is 8.49 m. In 8 years out of 10 the reading falls between 8.44 m and 8.55 m, based on 11 years of records.

What is the water level of Mary Lake at Port Sydney today?

On Oct 20, 2026, 03:45 PM EDT, the water level was 8.47 m. Steady over the last 24 hours.

Is Mary Lake at Port Sydney rising or falling?

Steady over the last 24 hours. Down 0.05 m over the last 7 days.

Is the level of Mary Lake at Port Sydney normal?

Normal for mid-October. Compared with 11 years of daily readings for this time of year.

How often is this data updated?

Environment and Climate Change Canada – Water Survey of Canada publishes a new reading every hour. This page refreshes within minutes of each update.

Where does this data come from?

The values come directly from Environment and Climate Change Canada – Water Survey of Canada, the official operator of this gauge, and are published under the Open Government Licence – Canada. We do not estimate or model live values.

For specialists

Station codes, datum, parameters, data quality and downloads

Operator: Environment and Climate Change Canada – Water Survey of Canada
Station code: eccc:02EB021 (Agency page)
Coordinates: 45.21986, -79.27639 (WGS84)
Vertical datum: station datum (assumed datum)
Update interval: every hour
Licence: Open Government Licence – Canada. Contains information licensed under the Open Government Licence – Canada

Published series

Parameter	Last value	Time (UTC)	Quality
Water level	8.47 m	2026-10-20 19:45	Provisional

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How to cite

Environment and Climate Change Canada – Water Survey of Canada: Mary Lake at Port Sydney (eccc:02EB021). Accessed October 20, 2026 via Nivelmap, https://nivelmap.com/en/canada/ontario/mary-lake-at-port-sydney

How we check values

Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.

Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer