New York, NY 21° Los Angeles, CA 24° 🌤️ Chicago, IL Houston, TX 28° 🌤️ Miami, FL 🌤️ Phoenix, AZ 🌤️ Seattle, WA 🌤️ Denver, CO Toronto, ON 20° Vancouver, BC 17°
WeatherLive › Ontario › Grand River South

Grand River South, ON Weather

Today Hourly 10-Day Weekend Monthly Radar Air Quality Climate
Current WeatherGrand River South · 11:22 AM EDT
27° | 9°
23°C
Feels like 22°
Sunny
WindSE 5 mph · Gusts 11 mph
Precip5% · –
Humidity50% · Dew point 12°
UV index7 High
Air Quality27 Good
Pressure30.12 inHg
Visibility6 mi
Sunrise / Sunset6:33 AM · 8:15 PM · 13h 42m

Weather map — Grand River South

Full radar →
Now
23°
2%
5 mph
12:00
24°
7%
7 mph
13:00
25°
7%
6 mph
14:00
26°
8%
6 mph
15:00
24°
1%
5 mph
16:00
27°
6%
6 mph
17:00
24°
1%
7 mph
18:00
23°
1%
10 mph
19:00
20°
3%
10 mph
20:00
20°
6%
8 mph
21:00
18°
8%
8 mph
22:00
17°
10%
7 mph
23:00
16°
20%
7 mph
00:00
16°
18%
7 mph
01:00
16°
14%
8 mph
02:00
16°
27%
8 mph
03:00
16°
32%
9 mph
04:00
16°
18%
8 mph
05:00
15°
38%
7 mph
06:00
15°
32%
7 mph
07:00
16°
31%
6 mph
08:00
17°
10%
5 mph
09:00
19°
5%
5 mph
10:00
21°
3%
6 mph

Today · Fri 8/21

High 27°
5% / –

Sunny. Winds SE at 10 mph.

Tonight · Fri 8/21

Low 15°
8% / –

Sunny. Winds E at 8 mph.

Tomorrow · Sat 8/22

26° | 15°
78% / 0.34 in

Sunny. Winds N at 11 mph.

7-day trend

Grand River South · temperature + precipitation

10-day forecast

Updated 11:22 AM

Details & indices

Wind
5 mph SE
Gusts 11 mph
Humidity
50%
Dew point 12°
Pressure
30.12 inHg
Rising
UV index
7 — High
High today
Air Quality
Good
AQI 27 · US EPA
Allergy
Very high
Mugwort
Visibility
6 mi
Clear view
Allergy — Grand River South

🌿 Conditions right now

View all →
Birch
None
Grass
High
Oak
None
Alder
None
Hazel
None
Mugwort
High
Ragweed
Low

Sun & moon

Sunrise6:33 AM
Sunset8:15 PM
Length of day13h 42m
Moonrise4:27 PM
Moonset—
Moon phase🌓 First Quarter · 64%
Next full moonAug 28 Sturgeon Moon
Latitude43.4504°N
Longitude-80.4043°E

Water temps nearby

View all →
No beaches within 50 miles
🌤️No rain expected in the next 90 minutes
Now+30+60+90 min
Minute-by-minute precip · HRRR nowcast

Daily planner

computed from today's forecast
Laundry day
Great
Line-drying weather
Grilling
Great
Fire up the grill
Running
Fair
Lace up outside
Patio
Great
Dinner outdoors
Nearby places in {{REGION}}
Toronto
Sunny
20° 🌤️
Ottawa
—
— 🌤️
Mississauga
—
— 🌤️
Brampton
—
— 🌤️
Hamilton
—
— 🌤️
London
—
—
Data sources · Friday, August 21
Where the Grand River South forecast comes from
This page blends NOAA/NWS model guidance with global ensembles for the 10-day outlook, air quality and alerts. Data refreshes every hour, current conditions every 15 minutes. Coordinates: 43.4504°N, -80.4043°.
NBM + global weather models
Updated: 11:22 AM
Weather in Grand River South
Grand River South's outlook: warmest day near 28° (Saturday), coldest night about 9° (Friday). Models drop roughly 0.83 in of precipitation across the stretch — watch Saturday (78%). The NWS alert board for this area is currently clear. Right now Grand River South is running about 61° warmer than Rochester. Longer view: four full seasons with serious winter and real summer heat.
Grand River South, ON · Elev 997 ft · 43.45°N, 80.40°W · Ontario · Forecast computed for these exact coordinates
Powered by NWS/NOAA guidance, multi-model forecasts and official environmental feeds · NOAA/NWS · EPA AirNow · MET Norway · global models
Updated: 11:22 AM