September 2025 Review

It's time for our big look back at Edmonton weather for a hot September 2025.

September 2025's average High of 23.8°C was the 2nd warmest on record, just behind 24°C from 1938. 

The average Low of 8.8°C was the 4th warmest. For recent years that joins 2024's 2nd warmest 9.2°C, and 2022's record of 9.4°C.

Even though September 2025's Highs and Lows weren't #1 individually, combined they made this the warmest September on record. For 2025 that joins our 5th warmest August, and 6th warmest May.

In recent years we've had:

• #1 May in 2023, #6 in 2025
• #1 June in 2021, #3 in 2023
• #1 July in 2024, #3 in 2023, #6 in 2022
• #1 August in 2022, #5 in 2025
• #1 September in 2025, #3 in 2022, #5 in 2024
• #1 October in 2022
• #1 December in 2023

The 5 months that haven't gotten new #1s since 2021 are January-April, and November.




High Temperatures

September 2025 was warm, with only 1 High below average (just barely) on the 24th. Most of the month was well above average, including 2 new daily records on the 13th and 20th.

September averages around 11 20°C Highs, and 2025 had...24? Yup, 24. 

That included 12 25°C Highs, when the average is around 3. 

There were no 30°C days, but it did have 3 29°C Highs on the 12th, 13th & 20th.

The coldest High was 15.9°C. September averages 8 Highs below 15°C.





Hot Days So Far

We're getting to the end of our hot days, and 2025 will likely end up with 14 30°C Highs, which ties 1961 for the 3rd most on record (behind only 2024 & 2021). 

And 2025's 56 25°C Highs is the 5th most on record, and the most since 1961 (1898's record is 64).



Low Temperatures

September's Lows were also mostly well above average, but did include 6 below-average days. But there were also 3 new daily records on the 14th, 17th & 18th.

September averages 6 Lows above 10°C, and 2025 had 13. 

It also averages 1 below-freezing Low, but 2025 was frost-free. The last time that we had a September frost was back in 2019.



2025 Records

So far 2025 has set 8 new daily record Highs. That's below 2024's 11, but above the 5 from 2021-2023. 

And 2025 has 6 record warmest-Lows. That's more than a lot of years, but 2021-2024 all ranged from 10-15.



Early Frost History

This shows Blatchford's history of early frosts, counting the 0°C Lows which occurred each year before October.

Right now we've gone 6 years without a September frost. The longest gap on record was 7 years from 1975-1981.

Around town, the airport did get its first frost on September 25th, which is about 2 weeks later than its average. And Campsie's September 5th frost was right on its average.



The Horserace

With 3 months left in 2025, its average temperature is currently our 5th warmest overall, at 2.1°C above the 20th century average.

That's due to a warm January (#13), May(#6), August (#5), and September (#1). 

The Highs are our 4th warmest, and Lows are 9th warmest.



Warm & Cold Months

September 2025 was well above average, so it's a big orange bubble here. The average High of 23.8°C was 6.9°C warmer than the 20th century average. The average Low of 8.8°C was 4.2°C warmer.



Across Canada

September 2025 another above-average month across the country. Edmonton was at the top at 6.9°C warmer than the 20th century average. Victoria was at the bottom, at 0.4°C warmer than theirs.



Precipitation

In September we average 32mm of precipitation, and 2025 was SUPER low.

The airport recorded 0.6mm (although it had quite a few missing records), Blatchford got to 0.9mm, and Stony Plain had 1.5mm.

Campsie (100km NW) got up to 13.3mm, but that's still well below average.

By the end of September we average around 377mm of precipitation for the year.

The dry September means that Campsie and the airport are a bit below average around 350mm.

But Stony Plain is way down at 267mm, and Blatchford is down at 250mm.

Storms? What storms? By September our big summer storm season is over, but we still average around 10 days with Precipitation. But not in 2025.



Snow

On the other hand, no September precipitation also means no September snow. The last time that we recorded September snow was September 28, 2019 in Stony Plain. And September 2018 was also very snowy.



Precipitation Across Canada

These are the precipitation totals for 2025 across the country.

Quebec City is still way out ahead with over 865mm. Montréal & St. John's are over 700mm. 

And like Edmonton, Calgary recorded basically no precipitation (0.4mm) in September.

Across the country the biggest September storms were: 

• 50mm in Regina
• 38mm & 23mm in Toronto
• 25mm in Quebec City
• 20mm in Charlottetown

October

For October, we average about 1~2 Highs of 20°C, but half of the time there are none.

October also averages 2 Highs below 0°C, and 14 freezing Lows. 

And...we get 7cm of snow on average in October, although 2021, 2022 & 2024 had none.

August 2025 Review & The Great Heatwave of August 2025

It's time for our big look back at Edmonton weather for August 2025. August has 31 days, but we're going to talk a lot about the final week. The word "unprecedented" gets thrown around a lot, but the end of August gave us a truly unprecedented heatwave.

August 2025's average High of 25.7°C was the 4th warmest on record. That's obviously hot, although recently 2022 got to 2nd spot with 26.6°C.

The average Low of 12.9°C was the 9th warmest. And again, that's warm. But it was actually below 2024, 2023 & 2022.





High Temperatures

August 2025 started warm, but then was maybe a little cool for a few weeks. 

But it ended with 8 straight 28°C Highs, 8 of which got to 30°C, and 4 of which got to 32°C. 

Overall there were 8 below-average Highs compared to 21 above-average, including 4 new records.

August averages around 10 25°C Highs, and 2025 had 19. 

That included 8 30°C Highs, when the average is around 1. 

The hottest was 33.3°C on the 27th. The coldest was 13.1°C on the 15th.





The Great Heatwave of August 2025

So what made this heatwave unique?

Our 30°C season can last from May-September, but it peaks in mid-July. From around June 22-August 18 is when we're most likely to reach 30°C. By August 25 we can still get there, but we're definitely out of the peak time.





Hot Days In-A-Row

The August heatwave gave us 6 30°C Highs in-a-row. That's the longest for this late in the year, and is 1 short of the all-time record set in July 2024 and July 2021. For late-August the previous record was only 3, and 2025 doubled that.

The August heatwave also gave us 4 32°C Highs in-a-row. That ties the all-time record from July 2021 and June 1961. And it also doubles the previous late-summer record, which was only 2 in-a-row.





Record Highs

We set 4 new record Highs in-a-row, from August 26th-29th. Those ranged from 32.2°C to 33.3°C, and were the 4th, 6th, 8th & 9th warmest temperatures ever recorded this late in the year.

Overall, 2025 now has 6 new record Highs. That's fewer that 2024's 11, but more than the 5 for 2021-2023. 

Just for the summer months of May-September, since 2021 we've set 29 new records, or about 20% of all of the days.





Hot Days So Far

The previous August record for 30°C days was 7, in 1967 & 1932. But 2025 sets a new record with 8. 

August 2025's 4 32°C days is also a new record, ahead of 3 in August 2008 & 1981. The 2 33°C days also tie 1922's record.

At the end of August, so far 2025 has had 14 30°C days. That ties 1964 for 3rd most ever recorded.

The only years with more? 2024 had 16, and 2021 had 17. (and with the forecast for September, we might catch them?)



Low Temperatures

And the Lows? Compared to the Highs they were a bit boring. For other recent heatwaves we had a lot of record-setting Lows, but August 2025 was warm without being flashy. 21 Highs were above-average and 10 were below.

August averages 4 Lows over 15°C, and 2025 had 7. But those were all early in the month. During the big heatwave dropped to around 12-14°C overnight.



The Horserace

How does the heatwave affect 2025's overall temperatures?

The mean temperature was already around top-20, and 1.5°C warmer than the 20th century average. 

August's hot week is visible here with the red line climbing upwards at the end, to around 13th warmest overall.



Warm & Cold Months

August 2025's average High of 25.7°C was 3.7°C warmer than the 20th century average, so it gets a medium orange bubble. But 2022 was warmer overall.

The average Low of 12.9°C was 3.3°C warmer also gets a medium orange bubble, similar to 2022-2024.



Across Canada

August 2025 another mostly above-average month across the country...except for Winnipeg. 

Kelowna & Edmonton were at the top, with Highs more than 3.7°C above their 20th century averages. 

Winnipeg was at the bottom, and -0.2°C below theirs.

One of the weird quirks of Edmonton's recent heatwaves is that this is the 2nd summer in-a-row where we've had as many (or even more) 30°C days than Winnipeg.



Precipitation

August averages 52mm of precipitation, which is our 3rd highest month.

In 2025 Blatchford was down at 28mm, Stony Plain got 44mm, the airport got 61mm, and Campsie (100km NW) got up to 114mm.

The big difference between the stations was the Blatchford's biggest day was only 11mm. The airport had 2 days around 15mm, and Campsie had 3 over 20mm.

By the end of August we average around 345mm of precipitation for the year (about 80% of our yearly total).

The airport and Campsie are right around average, while Stony Plain is at 266mm, and Blatchford is down at 248mm.



Precipitation Across Canada

These are the precipitation totals for 2025 across the country. Quebec City is still way out ahead with over 800mm. Montréal, St. John's & Halifax are over 600mm. Calgary is at 423mm, while Edmonton and the other prairie cities (also Kelowna & Victoria) are below 250mm.

Across the country the biggest August storms were: 

• Halifax & Vancouver over 40mm 
• Ottawa around 35mm 
• Quebec City, Toronto & St. John's around 25mm

September

For September we average 11 days at 20°C, including 3 at 25°C. And 2024 & 2022 both started with heatwaves.

For Lows, about half of the time September is frost-free, but right now our last September frost was 2019.

July 2025 Review

It's time for our big look back at July 2025 weather in Edmonton. Was it unseasonably cold? Kind of, but also not really? Let's take a look...

The general consensus seems to be that July 2025 was pretty cool. 

The average High of 23.9°C was our 52nd warmest on record, and above 2023 & 2020. 

The average Low of 12°C was our 49th warmest, and the coldest since 2019. 

So it was cool, but not particularly cold.





High Temperatures

July started and ended warm, but was a little cool in the middle. We only had 13 Highs above the 30-year average, compared to 18 below. 

The hottest was 31.9°C on the 2nd & 8th. The coldest was 16.3°C, which was July 21st's 5th coldest High on record.

July averages 12 25°C Highs, and 2025 had 12.

 

And it averages 3 30°C Highs, and 2025 got 3. 

The coldest High was 16.3°C on the 21st, but 2023, 2022 & 2021 all had Highs below 15°C.





Hot Days So Far

By the end of July we've had 62 20°C Highs. That's around average, and more than 2024, 2022, 2020, 2019. 

We've had 25 Highs reach 25°C - less than 2023, 2021 & 2018, but more than a lot of years.

July 31st was our 6th 30°C High of the year, so far.

This is the 5th summer in-a-row (2021-2025) to get to 6 of them. That's only happened once before, in 1932-1936.



Low Temperatures

July's Lows were pretty chilly, with only 12 above-average and 19 below.

And 4 of those were the coldest in at least 30 years. The 15th's 5.6°C and 23rd's 6.1°C were both bottom-10 Lows for those days.

Our range of July Lows is pretty narrow, usually between 5-20°C.

2025 had 8 cool Lows between 5-10°C, when the average is only 4.



Warm & Cold Months

July 2025 was cooler than recent years, but still warmer than the 20th century average, so it gets another small orange bubble.

The average High of 23.9°C was 0.6°C warmer than the 20th century average, and the Low of 12°C was 1°C warmer.



Across Canada

July 2025 was not warm in Edmonton, but it was actually cool in Calgary, Saskatoon & Regina, with Highs around 2°C below their 20th century averages. The rest of the country's Highs were around 2°C warmer than theirs.

For 30°C days so far this summer central Canada is a little above average, while Saskatoon & Regina are pretty low.



Precipitation

July is typically our rainiest month, averaging 90mm.

In 2025 the airport got up to 102mm, while the other stations were below 40mm.

The big difference was that the airport got a 20mm storm on the 6th, and 17mm storms on the 19th & 20th.

Blatchford's biggest day was only 12.7mm on the 19th.

By the end of July we average around 290mm of precipitation for the year.

The airport is right on average, and the other stations are down around 230mm.

These are the precipitation totals for 2025 across the country.

Quebec City is at the top with 750mm, which is their 20th most on record.

Calgary's 375mm is well ahead of Edmonton's 220mm, and is their 17th most.

And Winnipeg's 126mm is another low year for them.

Across the country the biggest July storms were:

• Montréal with 81.6mm on the 13th
• Toronto with 48mm on the 20th
• Quebec City with a whole bunch (6) ~30mm days.

August

For August on average we have 25 Highs which reach 20°C, including ~10 above 25°C. About half of the time August hits 30°C.

Most Lows are 10~15°C, but half of the time August will have a night below 5°C.

And August is our 3rd rainiest month averaging 52mm.