Observed at: St. Catharines Airport
Date: Wednesday June 20, 2018 at 03:00 EDT
Temp.: 14.3 °C
Wind: SW 2 km/h
Humidity: 89 %
Dew point: 12.6 °C
Pressure: 101.3 kPa
Tendency:
Sunrise: 05:37
Sunset: 21:00
Normals:
Max 25°C Min 14°C
Yesterday
  Max: °C
  Min: °C
  Rainfall: mm

 Extended Forecast - Environment Canada
  Wednesday
Mainly sunny
Mainly sunny
Max: 27°C
Thursday
A mix of sun and cloud
A mix of sun and cloud
Max: 22°C
Friday
A mix of sun and cloud
A mix of sun and cloud
Max: 24°C
Saturday
Chance of showers (60%)
Chance of showers
Max: 20°C
Sunday
Chance of showers (30%)
Chance of showers
Max: 19°C
Monday
A mix of sun and cloud
A mix of sun and cloud
Max: 21°C
Tuesday night
Partly cloudy
Partly cloudy
Min: 14°C
Wednesday night
Clear
Clear
Min: 15°C
Thursday night
Cloudy periods
Cloudy periods
Min: 15°C
Friday night
Chance of showers (30%)
Chance of showers
Min: 15°C
Saturday night
Chance of showers (40%)
Chance of showers
Min: 17°C
Sunday night
Cloudy periods
Cloudy periods
Min: 15°C

Forecast

St. Catharines, ON (Issued: Tuesday June 19, 2018 at 15:30 EDT)

Tonight
Partly cloudy. Wind north 20 km/h becoming light this evening. Low 14.
Wednesday
Mainly sunny. High 27 except 22 near Lake Ontario. Humidex 29. UV index 10 or very high.
Wednesday night
Clear. Low 15.
Thursday
A mix of sun and cloud. High 22.
Thursday night
Cloudy periods. Low 15.
Friday
A mix of sun and cloud. High 24.
Friday night
Cloudy with 30 percent chance of showers. Low 15.
Saturday
Cloudy with 60 percent chance of showers. High 20.
Saturday night
Cloudy with 40 percent chance of showers. Low 17.
Sunday
A mix of sun and cloud with 30 percent chance of showers. High 19.
Sunday night
Cloudy periods. Low 15.
Monday
A mix of sun and cloud. High 21.
Averages and extremes
Highest temperature(1972-2000)32.9 °C1988
Lowest temperature(1972-2000)8.5 °C1992
Average high24.9 °C 
Average low14.0 °C 
Average19.5 °C 
Greatest rainfall(1972-2000)14.2 mm1989
Greatest snowfall(1972-2000)0.0 cm1972
Greatest precipitation(1972-2000)14.2 mm1989
Most snow on the ground(1972-2000)0.0 cm1972
Monthly frequency of precipitation36.0 % 

24 Hour Forecast - St. Catharines, ON

Date/Time
(EDT)
Temp.
(°C)

Weather Conditions

LOP †
Wind
(km/h)

Humidex
20 June 2018
04:00 14 Partly cloudy (0%)  Partly cloudy Nil N 10
05:00 14 Partly cloudy (0%)  Partly cloudy Nil N 10
06:00 15 Mainly sunny (0%)  Mainly sunny Nil N 10
07:00 16 Mainly sunny (0%)  Mainly sunny Nil N 10
08:00 17 Mainly sunny (0%)  Mainly sunny Nil N 15
09:00 19 Mainly sunny (0%)  Mainly sunny Nil N 15
10:00 20 Mainly sunny (0%)  Mainly sunny Nil N 15
11:00 22 Mainly sunny (0%)  Mainly sunny Nil NE 10
12:00 23 Mainly sunny (0%)  Mainly sunny Nil NE 10 25
13:00 24 Mainly sunny (0%)  Mainly sunny Nil NE 10 26
14:00 25 Mainly sunny (0%)  Mainly sunny Nil NE 10 27
15:00 26 Mainly sunny (0%)  Mainly sunny Nil NE 10 28
16:00 26 Mainly sunny (0%)  Mainly sunny Nil NE 10 28
17:00 27 Mainly sunny (0%)  Mainly sunny Nil NE 10 29
18:00 26 Sunny (0%)  Sunny Nil NE 10 28
19:00 25 Sunny (0%)  Sunny Nil NE 10 28
20:00 24 Sunny (0%)  Sunny Nil NE 10 27
21:00 22 Clear (0%)  Clear Nil NE 10 25
22:00 21 Clear (0%)  Clear Nil NE 10
23:00 19 Clear (0%)  Clear Nil NE 10
21 June 2018
00:00 18 Clear (0%)  Clear Nil NE 10
01:00 17 Clear (0%)  Clear Nil NE 10
02:00 16 Clear (0%)  Clear Nil NE 10
03:00 16 Clear (0%)  Clear Nil NE 10
 
† 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