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WeatherLive › Ontario › St. Catharines

St. Catharines, ON Weather

Today Hourly 10-Day Weekend Monthly Radar Air Quality Climate
Current WeatherSt. Catharines · 10:01 PM EDT
28° | 19°
21°C
Feels like 19°
Partly cloudy
WindN 14 mph · Gusts 20 mph
Precip80% · 4.81 in
Humidity74% · Dew point 16°
UV index7 High
Air Quality39 Good
Pressure29.91 inHg
Visibility6 mi
Sunrise / Sunset6:27 AM · 8:14 PM · 13h 47m

Weather map — St. Catharines

Full radar →
Now
20°
20%
14 mph
23:00
19°
25%
12 mph
00:00
19°
23%
9 mph
01:00
18°
28%
9 mph
02:00
19°
28%
7 mph
03:00
19°
27%
7 mph
04:00
18°
28%
7 mph
05:00
18°
26%
7 mph
06:00
17°
29%
8 mph
07:00
19°
10%
5 mph
08:00
20°
2%
4 mph
09:00
20°
2%
6 mph
10:00
20°
2%
6 mph
11:00
20°
2%
5 mph
12:00
20°
2%
2 mph
13:00
21°
1%
2 mph
14:00
22°
1%
4 mph
15:00
23°
1%
3 mph
16:00
23°
3%
1 mph
17:00
24°
4%
1 mph
18:00
24°
2%
2 mph
19:00
24°
2%
3 mph
20:00
23°
2%
4 mph
21:00
22°
3%
7 mph

Today · Wed 8/19

High 28°
80% / 4.81 in

Sunny. Winds W at 14 mph.

Tonight · Wed 8/19

Low 17°
25% / –

Partly cloudy. Winds N at 12 mph.

Tomorrow · Thu 8/20

24° | 17°
36% / 0.01 in

Sunny. Winds N at 9 mph.

7-day trend

St. Catharines · temperature + precipitation

10-day forecast

Updated 10:01 PM

Details & indices

Wind
14 mph N
Gusts 20 mph
Humidity
74%
Dew point 16°
Pressure
29.91 inHg
Rising
UV index
7 — High
High today
Air Quality
Good
AQI 39 · US EPA
Allergy
Low
Mugwort
Visibility
6 mi
Clear view
Allergy — St. Catharines

🌿 Conditions right now

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

Sun & moon

Sunrise6:27 AM
Sunset8:14 PM
Length of day13h 47m
Moonrise2:17 PM
Moonset11:14 PM
Moon phase🌓 First Quarter · 50%
Next full moonAug 28 Sturgeon Moon
Latitude43.1713°N
Longitude-79.2427°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
Fair
Line-drying weather
Grilling
Fair
Fire up the grill
Running
Poor
Lace up outside
Patio
Fair
Dinner outdoors
Nearby places in {{REGION}}
🌤️
Toronto
—
— 🌤️
Ottawa
—
— 🌤️
Mississauga
—
— 🌤️
Brampton
—
— 🌤️
Hamilton
—
— 🌤️
London
—
—
Data sources · Wednesday, August 19
Where the St. Catharines 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: 43.1713°N, -79.2427°.
NBM + global weather models
Updated: 10:01 PM
Weather in St. Catharines
The 10-day span for St. Catharines runs from a high near 28° on Wednesday down to 16° overnight on Monday. Roughly 6.3 in of rain falls over the period, with Friday the most likely wet day (92%). Wind is the one to watch: gusts to 30 mph around Friday. No watches or warnings are active for the area right now. Right now St. Catharines is running about 51° warmer than London. Longer view: four full seasons with serious winter and real summer heat.
St. Catharines, ON · Elev 335 ft · 43.17°N, 79.24°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: 10:01 PM