🇨🇦 Weather in St. Catharines
Map Overlays:
Hourly Forecast for St. Catharines
19:00
18°
66%
20:00
17°
75%
21:00
17°
81%
22:00
17°
80%
23:00
17°
81%
00:00
17°
81%
01:00
17°
35%
02:00
18°
33%
03:00
17°
24%
04:00
17°
12%
05:00
17°
25%
06:00
17°
25%
07:00
17°
23%
08:00
17°
27%
09:00
18°
19%
10:00
18°
13%
11:00
19°
7%
12:00
19°
10%
13:00
20°
14%
14:00
20°
8%
15:00
21°
13%
16:00
21°
8%
17:00
21°
9%
18:00
21°
13%
14-Day Forecast for St. Catharines
2026-08-24
Patchy rain nearby
20° /
13°
2026-08-25
Patchy rain nearby
21° /
17°
2026-08-26
Overcast
24° /
17°
2026-08-27
Sunny
25° /
19°
2026-08-28
Sunny
22° /
19°
2026-08-29
Overcast
20° /
16°
2026-08-30
Overcast
20° /
17°
Additional Forecasts for St. Catharines
Air Quality
💨 US EPA Index 1 (Good)
CO (Carbon Monoxide) 197.0 μg/m³
O₃ (Ozone) 54.0 μg/m³
NO₂ (Nitrogen Dioxide) 6.2 μg/m³
SO₂ (Sulphur Dioxide) 2.0 μg/m³
PM2.5 (Fine particles) 2.5 μg/m³
PM10 (Coarse particles) 2.5 μg/m³
Historical Weather
Weather Forecasts for Other Cities in Canada
Weather in St. Catharines — FAQ
Answers refreshed each request based on current conditions in St. Catharines.
What is the weather like right now in St. Catharines?
Right now in St. Catharines, Canada the temperature is 18.2°C (feels like 12.9°C), with light drizzle. Relative humidity is 81% and wind is 35.6 km/h.
What is today's high and low temperature in St. Catharines?
Today's forecast high in St. Catharines is 19.6°C and the overnight low is 13.1°C. The diurnal range — high minus low — depends on cloud cover; clear days swing more than overcast ones.
Will it rain in St. Catharines today?
The chance of precipitation in St. Catharines today is 87%. Forecast accuracy is highest within the next 6 hours and decreases steadily out to 14 days.
How often does the weather here update?
Current observations refresh every 15-60 minutes from the nearest monitoring stations operated by national meteorological agencies. The hourly forecast updates approximately every hour; the 7- and 14-day outlook is recomputed several times per day.
What does 'feels like' temperature mean?
Feels-like (apparent) temperature accounts for humidity, wind chill and direct sunshine — variables that change how the human body perceives heat or cold. On hot, humid days it can be 3-7°C above the actual reading; on cold windy days it can be 5-15°C below.
Why does the temperature in St. Catharines differ from nearby cities?
Even short distances can change temperatures noticeably. St. Catharines's reading reflects altitude, proximity to large bodies of water, urban heat island effects, and the exact location of the monitoring stations supplying the data. Coastal cities are typically milder and more humid than inland equivalents.