St. Mary River at Lethbridge
Water level and flow at gauge 05AE006, Alberta. The flow is normal for October (167% of the median). In the last 24 hours it has been steady.
Latest reading Oct 25, 5 AM local standard time (2 hours ago) · data checked · we check every 30 minutes
Compared with a normal October
Normal for October (middle half of 111 years of monthly averages): 3.27 m³/s115 cfs – 11.8 m³/s415 cfs, median 5.98 m³/s211 cfs. Right now it is at 167% of the median.
June 18, 2010 · approved records 1918–2024 (HYDAT). Right now the flow is 1% of that record.
Last 30 days
Hourly readings · shaded: normal range for this month
This year compared with past years
Daily flow
Normal range: monthly averages of 112 years (lighter band: 10th–90th percentile). Past years: approved daily means from HYDAT, the Water Survey of Canada archive (the latest year published is 2025). 2026: daily means of the provisional real-time readings collected by Canada River Levels since October 22, 2026.
Weather near this gauge
Cloudy. 40 percent chance of flurries early this morning. Becoming a mix of sun and cloud near noon. Wind up to 15 km/h. High plus 3. Wind chill minus 6 this morning. UV index 2 or low.
Partly cloudy. Wind up to 15 km/h. Low minus 7. Wind chill minus 10 overnight.
A mix of sun and cloud. Wind becoming southeast 20 km/h near noon. High 7. Wind chill minus 10 in the morning. UV index 2 or low.
Increasing cloudiness. Low minus 4.
Forecast for Lethbridge (13 km away) from Environment and Climate Change Canada, issued . Full official forecast ↗ · we check for new forecasts every 2 hours.
Nearby gauges
| Pothole CreekRussell'S Ranch · 2 km | 0.58 m1.92 ft | Below normal |
| Prairie Blood CouleeLethbridge · 8 km | 0.62 m2.04 ft | Normal |
| Oldman RiverLethbridge · 15 km | 0.38 m1.24 ft | Normal |
| Milk River Ridge Reservoir05AF030 · 28 km | 1,032.07 m3,386.06 ft | Very high |
| Piyami DrainPicture Butte · 29 km | 0.51 m1.67 ft | Very low |
| Magrath Irrigation District CanalSpring Coulee · 29 km | — | Very low |
About this gauge
Station: 05AE006 · St. Mary River Near Lethbridge
Location: 49.5735, -112.8467 · Alberta
Water levels are measured from a local reference point at each gauge, not from sea level, so they cannot be compared between gauges.
Official sources
For flood warnings, advisories and approved data, always use these official services:
Questions
What is the water level of the St. Mary River at Lethbridge today?
The latest reading (Oct 25, 5 AM, local standard time) is 1.30 m (4.27 ft) with a flow of 10.0 m³/s (353 cfs).
Is the St. Mary River at Lethbridge high right now?
The flow is normal for October (167% of the median).
Is the St. Mary River rising or falling?
In the last 24 hours it has been steady.
What is the highest flow ever recorded on the St. Mary River at Lethbridge?
1,050 m³/s (37,080 cfs) on June 18, 2010, the highest instantaneous flow in the approved records of the Water Survey of Canada (1918–2024). Events after 2024 are not yet in the approved archive.
Where does this data come from?
Gauge 05AE006 of the Water Survey of Canada (Environment and Climate Change Canada). Real-time data are provisional and may be revised. We check for new readings every 30 minutes. Canada River Levels is not an official source.