Rob’s Obs

All time hottest September temperature for Canada set today at Ashcroft BC with a sizzling 40.8C. Beats previous record of 40.0C set in Morden MB (Sep 1906), Lost River SK (Sep 1940) and Lytton BC (Sep 2025) (TWN graphic)

Even hotter than yesterday in Eastern Canada!
All-time records were set at several stations, and the all-time PEI record was shattered with 38.1° at Maple Plains!
36.7° in Badger, NL tied August record for NL and all-time record for the island. 38.6° in Miramichi is 0.8° below NB all-time record. ♨️

How are we doing for the first half of July in terms of temperature? Top 5 to Top 10 coolest in parts of Texas, but much warmer than normal across much of the northern tier.

Areas of heavier rainfall across Niagara over past 24 hours brought 25-50 mm over localized areas. Otherwise only 5-10 mm between heavier bands with less than 5 mm west of Grimsby.

One lone band of cumulus clouds over Niagara nicely marks convergent zone between Lake Erie and Lake Ontario lake breezes this afternoon

CoCoRaHS report from Morriston ON, east of Cambridge.. 90 mm of rain last night in less than 90 minutes

Quite the soaker through the Cambridge area last night.. upwards of 75-100 mm of rain reported, much of it falling between 10 pm and 1 am.

Area of showers over Lake Ontario will clip north St Catharines into NOTL over the next hour. Heads up if your boating in this area for some gusty showers moving in.

Quite the soaker across parts of Niagara this morning. Heavier cells early this morning gave 30-50 mm of rain through the Niagara Falls-Chippawa area in just over an hour. (Radar image from 530 am)

Max temps across Niagara today (Jun 24):

Vineland: 35.6C
Grimsby: 35.5C
St Catharines: 35.4C
Beamsville: 35C
Niagara Falls: 33.9C
Welland: 33.1C
Port Colborne: 29C

These are the hottest temperatures recorded in Niagara since July 2020.

Just popped another degree...likely the final one for the day. Boston reaches a June record of 102F. #wbz

33-36C temps over much of Niagara this afternoon.. except 28C near Lake Erie. Last day of the really hot stuff before less oppressive conditions Wednesday

Peak humidex values this afternoon will range from 38C near Lake Erie to 45C over north Niagara

One more day of oppressive heat and humidity over Niagara today with highs of 35C over north Niagara to 28C near Lake Erie. A slight chance of showers or thunderstorms later today into tonight then not as hot Wednesday

One more day of oppressive heat and humidity over Niagara Tuesday with highs of 32C over south Niagara to 35C north. A chance of showers or thunderstorms Tue pm/night then not as hot Wednesday

Max temps across Niagara today (Jun 23) through 5 pm:
Grimsby: 36.0C
Vineland: 35.2C
St Catharines: 34.5C
Niagara Falls: 33.3C
Welland: 32.4C
Port Colborne: 28C

A maximum of 36.0C at Toronto Pearson airport as of 5 pm. This is the 2nd hottest June temperature on record for Toronto, surpassed only by 36.7C on Jun 30 1964. The 36.0C is the hottest day in Toronto since at least Jul 13 2016 (also 36.0)

2 pm temps across Niagara (Jun 23):
- Grimsby: 35C (unofficial)
- Vineland: 34.3C
- St Catharines: 33.8C
- Niagara Falls: 33.3C
- Welland: 31.9C
- Port Colborne: 28C
Humidex values ranging from 40-44. Official 2 pm hot spot in Ontario is Toronto Pearson at 34.8C.

St Catharines already up to 29C as of 9 am. Likely hitting a record high 35C this afternoon. Recall that two days ago Env Canada was forecasting a *high* of only 27C for St Catharines for today. Faulty forecast algorithm leading to poor temperature forecasts in Niagara.

Today’s hot spots in Ontario via official ECCC network:

- Delhi: 35.3C
- Hamilton RBG: 35.3C
- Toronto Pearson 34.8C

Both Delhi and Hamilton RBG set new record highs for the date (Jun 22). Toronto Pearson was just short of today’s record high of 35.5C in 2022.

Maximum temperatures across Niagara today (Jun 22) as of 5 pm:
Grimsby: 35.5C
Beamsville: 35C
Vineland: 33.9C
St Catharines: 33.6C
Queenston: 33C
Niagara Falls: 32.8C
Welland: 31.4C
Port Colborne: 28C

Lake Erie lake breeze has pushed up into northern Niagara as of 2 pm marked by edge of CU field. That has stabilized temperatures in the 27-30C range over south Niagara while 32-35C heat continues over north Niagara

Env Canada drastically underforecasting max temps for Niagara especially Monday and Tuesday. Actual highs will be some 8C above current forecast highs. I suspect this will be adjusted on subsequent forecasts..

My forecast highs across Niagara Sunday through Tuesday. Hottest temps will across northern Niagara with highs of 33-36C each day. A bit cooler over south Niagara with SW flow off Lake Erie giving temps of 27-32C. Humidex values of 35-45C each day. Stay cool!

Oddly, Env Canada drops forecast highs for Niagara on Mon/Tue to 26-27C after issuing heat warning for highs of 31-36C through Tuesday. Very inconsistent messaging there.. 🤔🤷🏼‍♂️

Quite the heatwave coming up for Niagara and GTA. Highs of 32-35C Sunday-Tuesday with peak humidex values in the 40-45C range. Likely hottest stretch of June weather in Niagara since June 2012.

Rainfall accumulation map based on personal weather station observations in St Catharines area. Most of this fell between 2 and 330 pm.

Quite the deluge over St Catharines over the past hour. Generally 25-50 mm over central and northern parts of the city.. much less to the south

Rain has finally ended in Niagara after 2 straight days of steady rainfall. 2 day totals of 40-70 mm across Niagara, Hamilton and Haldimand areas. #ONstorm

UPDATED rainfall totals across Niagara, Hamilton and Haldimand areas as of 5 pm May 22, since yesterday. Generally 30-60 mm of rain has fallen across the area.. heaviest amounts over west Niagara, Hamilton and Haldimand areas where 50-70 mm of rain has been reported. Creeks running high and fast.