Nottawasaga River at Alliston
Water level and flow at gauge 02ED101, Ontario. The flow is normal for October (83% of the median). In the last 24 hours it has been steady.
Latest reading Oct 25, 8 AM local standard time (about an hour ago) · data checked · we check every 30 minutes
Compared with a normal October
Normal for October (middle half of 37 years of monthly averages): 1.49 m³/s52.6 cfs – 2.44 m³/s86.2 cfs, median 1.93 m³/s68.2 cfs. Right now it is at 83% of the median.
June 26, 2000 · approved records 1970–2025 (HYDAT). Right now the flow is 3% of that record.
2% lower than on October 25, 2025 (1.65 m³/s58.3 cfs)
approved daily mean (HYDAT)
Last 30 days
Hourly readings · shaded: normal range for this month
This year compared with past years
Daily flow
Normal range: monthly averages of 36 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
Sunny. Fog patches dissipating this morning. Wind becoming southwest 20 km/h late this morning. High 19. UV index 4 or moderate.
Partly cloudy. Becoming cloudy after midnight with 30 percent chance of showers overnight. Low 9.
Cloudy. 30 percent chance of showers in the morning. Wind northwest 20 km/h gusting to 40. High 13. UV index 2 or low.
Cloudy. Low minus 2.
Forecast for Alliston (5 km away) from Environment and Climate Change Canada, issued . Full official forecast ↗ · we check for new forecasts every 2 hours.
Nearby gauges
| Boyne RiverEarl Rowe Park · 5 km | 2.86 m9.38 ft | Below normal |
| Innisfil CreekAlliston · 9 km | 1.91 m6.28 ft | Normal |
| Beeton CreekTottenham · 10 km | 5.68 m18.63 ft | Normal |
| Pine RiverEverett · 11 km | -0.02 m-0.05 ft | Very low |
| Nottawasaga RiverHockley · 11 km | 0.67 m2.20 ft | Below normal |
| Humber RiverHighway No. 9 · 16 km | 2.22 m7.27 ft | Below normal |
Official sources
For flood warnings, advisories and approved data, always use these official services:
Questions
What is the water level of the Nottawasaga River at Alliston today?
The latest reading (Oct 25, 8 AM, local standard time) is 6.73 m (22.07 ft) with a flow of 1.61 m³/s (56.9 cfs).
Is the Nottawasaga River at Alliston high right now?
The flow is normal for October (83% of the median).
Is the Nottawasaga River rising or falling?
In the last 24 hours it has been steady.
What is the highest flow ever recorded on the Nottawasaga River at Alliston?
48.3 m³/s (1,706 cfs) on June 26, 2000, the highest instantaneous flow in the approved records of the Water Survey of Canada (1970–2025). Events after 2025 are not yet in the approved archive.
How does the Nottawasaga River at Alliston compare with a year ago?
The flow is 2% lower than on October 25, 2025 (1.65 m³/s (58.3 cfs), approved daily mean (HYDAT)).
Where does this data come from?
Gauge 02ED101 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.