Observed at: St. Catharines Airport
Date: Tuesday August 14, 2018 at 15:00 EDT
Mostly Cloudy
Mostly Cloudy
Temp.: 28.1 °C
Humidex: 32
Wind: WNW 12 km/h
Humidity: 44 %
Dew point: 14.9 °C
Pressure: 101.2 kPa
Tendency: falling
Visibility: 24.1 km
Sunrise: 06:21
Sunset: 20:22
Normals:
Max 26°C Min 16°C
Yesterday
  Max: °C
  Min: °C
  Rainfall: mm

 Extended Forecast - Environment Canada
  Wednesday
A mix of sun and cloud
A mix of sun and cloud
Max: 30°C
Thursday
Chance of showers (40%)
Chance of showers
Max: 25°C
Friday
Chance of showers (60%)
Chance of showers
Max: 24°C
Saturday
A mix of sun and cloud
A mix of sun and cloud
Max: 24°C
Sunday
Sunny
Sunny
Max: 25°C
Monday
A mix of sun and cloud
A mix of sun and cloud
Max: 26°C
Tuesday night
Chance of showers (30%)
Chance of showers
Min: 19°C
Wednesday night
Chance of showers (70%)
Chance of showers
Min: 19°C
Thursday night
Showers or thundershowers
Showers or thundershowers
Min: 21°C
Friday night
Cloudy periods
Cloudy periods
Min: 18°C
Saturday night
Cloudy periods
Cloudy periods
Min: 18°C
Sunday night
Clear
Clear
Min: 19°C

Forecast

St. Catharines, ON (Issued: Tuesday August 14, 2018 at 15:30 EDT)

Tonight
Partly cloudy. 30 percent chance of showers early this evening. Clearing late this evening. Low 19.
Wednesday
A mix of sun and cloud. Wind becoming west 20 km/h in the afternoon. High 30. Humidex 37. UV index 8 or very high.
Wednesday night
Partly cloudy. 70 percent chance of showers before morning with risk of a thunderstorm. Wind west 20 km/h becoming light in the evening. Low 19.
Thursday
Cloudy with 40 percent chance of showers. High 25.
Thursday night
Showers or thunderstorms. Low 21.
Friday
A mix of sun and cloud with 60 percent chance of showers. High 24.
Friday night
Cloudy periods. Low 18.
Saturday
A mix of sun and cloud. High 24.
Saturday night
Cloudy periods. Low 18.
Sunday
Sunny. High 25.
Sunday night
Clear. Low 19.
Monday
A mix of sun and cloud. High 26.
Averages and extremes
Highest temperature(1971-2000)32.7 °C1988
Lowest temperature(1971-2000)9.8 °C1992
Average high26.2 °C 
Average low16.0 °C 
Average21.1 °C 
Greatest rainfall(1971-2000)50.3 mm1972
Greatest snowfall(1971-2000)0.0 cm1971
Greatest precipitation(1971-2000)50.3 mm1972
Most snow on the ground(1971-2000)0.0 cm1971
Monthly frequency of precipitation31.0 % 

24 Hour Forecast - St. Catharines, ON

Date/Time
(EDT)
Temp.
(°C)

Weather Conditions

LOP †
Wind
(km/h)

Humidex
14 August 2018
16:00 29 Chance of showers (30%)  Chance of showers Low NW 15 35
17:00 29 Chance of showers (30%)  Chance of showers Low NW 15 35
18:00 28 Chance of showers (30%)  Chance of showers Low NW 15 34
19:00 27 Chance of showers (30%)  Chance of showers Low NW 15 33
20:00 26 Partly cloudy (0%)  Partly cloudy Nil NW 15 32
21:00 25 Partly cloudy (0%)  Partly cloudy Nil VR 5 31
22:00 25 Clear (0%)  Clear Nil VR 5 31
23:00 24 Clear (0%)  Clear Nil VR 5 30
15 August 2018
00:00 23 Clear (0%)  Clear Nil VR 5 29
01:00 23 Clear (0%)  Clear Nil VR 5 29
02:00 22 Clear (0%)  Clear Nil VR 5 28
03:00 21 A few clouds (0%)  A few clouds Nil VR 5 26
04:00 20 A few clouds (0%)  A few clouds Nil VR 5 25
05:00 19 A few clouds (0%)  A few clouds Nil VR 5
06:00 21 Mainly sunny (0%)  Mainly sunny Nil VR 5 26
07:00 22 Mainly sunny (0%)  Mainly sunny Nil VR 5 29
08:00 24 Mainly sunny (0%)  Mainly sunny Nil VR 5 32
09:00 25 Mainly sunny (0%)  Mainly sunny Nil NW 10 33
10:00 26 Mainly sunny (0%)  Mainly sunny Nil NW 10 34
11:00 27 Mainly sunny (0%)  Mainly sunny Nil NW 10 35
12:00 28 A mix of sun and cloud (10%)  A mix of sun and cloud Low NW 10 36
13:00 28 A mix of sun and cloud (10%)  A mix of sun and cloud Low NW 10 36
14:00 29 A mix of sun and cloud (10%)  A mix of sun and cloud Low NW 10 37
15:00 29 A mix of sun and cloud (10%)  A mix of sun and cloud Low W 20 37
 
† Likelihood of Precipitation (LOP) as described in the public forecast as a chance of measurable precipitation for a period of time.
  Nil: 0%
  Low: 40% or below
  Medium: 60% or 70%
  High: Above 70%
‡ Value not significant

Environment Canada