2018/07/11

Record Watch: July 14th

Right now the forecast for Saturday, July 14th is calling for a High temperature of 13°C. If that happens, would it be a record?

July 14th Temperatures

So no, Edmonton's coldest July 14th since 1880 was in 1913, with a High of 9.4°C. The 2nd coldest was in 1999 at 14.3°C, and then there's a 3-way tie at 14.4°C between 1934, 1937 and 1950 for 3rd coldest. And those 5 years were the only times with temperatures below 15°C.

Coldest Highs for the Week of July 11-17

If we look at this week of the year - July 11th through 17th - the 14th has the coldest all-time record at 9.4°C. The all-time coldest record for the 17th is 6.2°C warmer, up at 15.6°C.

If we do top out at around 13°C this year, then that would make this the 2nd coldest July 14th, and would be in the bottom-10 coldest for the week.

2018/07/04

2018 Mid-Year Review

We're 6 months into 2018, so lets take a quick look at how things have gone so far:

High Temperatures

This chart shows the High temperatures for the year.

The colourful stuff in the background of this chart is the range of temperatures that have been recorded since 1996. The average high for each day is the white line in the centre; it is surrounded by a grey band for the 25th-75th percentiles (where temperatures will fall roughly half of the time); and outside of that are the warmest temperatures since 1996 in orange and the coldest in light blue. And finally, the all-time warmest and coldest temperatures going back to 1880 are shown as the faint lines that are furthest from the average.

The red & dark blue highlighting shows days that were above or below average. Since late-April we've been pretty consistently above average, but February and April were both below.

The labels in the chart get a little crowded, but they show any days which set a recent (since-1996) record. From February through mid-April there were 6 recent-coldest High temperatures, including one all-time coldest High on April 6th at -8.6°C. And then from late-April through the end of June there were 15 recent-warmest Highs, although no all-time records.


Low Temperatures

Here we have the Low temperatures.

So far this year we've set 10 recent-coldest Lows, which were mostly clumped together in February and late-March/early-April. We've also set 10 recent-warmest Lows, including 3 all-time warmest Lows on May 8th, May 24th, and June 25th.


The Horserace

How does 2018 compare to other recent years?

This chart tracks how much warmer each day of the year was compared to the 20th century average - warm days get points and cold days lose them. The blue and orange background is the range of all the years going back to 1880, and each of the last 10 years is shown as an individual line. For a full explanation of this chart it's easiest to refer back to the original discussion of it in How warm is 2016? (September Edition).

The red line for 2018 starts off warm in January, but the colder-than-average April dropped it down below the 20th century average and into the realm of other cold recent years like 2009, 2011 & 2014. Our warm June and very warm May pushed it back up again though, so now we're roughly tied with 2008 & 2013, but still on the cool side of things for recent years.


Warm & Cold Months

This chart is admittedly less about being informative, and more about being cool. But it does break down the temperatures for each year on a monthly basis, and the full explanation of what's going is in How Warm is 2017 - the Months.

This compares the average temperature for each month of 2018 to the average for the 20th century, and to the average for the last 5 years:
  • The overall average temperature this January was pretty warm, at 4.2°C above the 20th century average. But most recent January's have also been pretty warm - the 5-year average is actually 5.4°C above the 20th century. So this January was 4.2°C warmer than history, but -1.2°C colder than recent years.
  • February was -2.2°C below the 20th century average and -3.5°C below recent years.
  • March was -0.5°C below the 20th century average and -2.2°C below recent years.
  • April was -2.6°C below the 20th century average, which made it Edmonton's 23rd-coldest April. It was also -3°C below recent years.
  • May was 4.7°C above the 20th century average, and the warmest May ever recorded. That also made it 2.9°C warmer than recent years.
  • And June was 2.4°C above the 20th century average, or the 6th-warmest June. It was 0.5°C warmer than recent years.
So the average temperatures for January through April were all 1-3°C colder than what we'll typically get, but then May and June have both rebounded.


Precipitation

And finally, here we have the total precipitation (rain & snow) for the year so far.

At the end of 2017 we saw a large gap between Blatchford and the International Airport - with Blatchford receiving 375mm compared to 490 at the International. In 2018 we're seeing another large gap, with Blatchford at 135mm while the International is 56mm higher at 191mm. We're really just at the start of thunderstorm season though, so we'll need to see how the rest of the summer goes.

2018/07/02

Canada Day 2018

Here's a quick look at the history of temperatures records in Edmonton for Canada Day:


The 2018 High of 19.8°C was a bit below the average of 22°C, and made this the 29th coldest Canada Day since 1881 (so 29th out of 137). That was still warmer than 2010 or 2011, though. And the Low of 11°C was just a bit below average.

2018/07/01

June Review / July Preview

Edmonton Weather Nerdery has been pretty quiet this month, but as we look back at June we'll see that it was a pretty quiet month overall for Edmonton weather:

High Temperatures

We didn't set any all-time High temperature records this June, but we did set 6 recent (since 1996) records. Combined with the 8 that we set in May that makes 14 hottest-days-since-1996 in the last two months.

For the last week of June things noticeably cooled off, but that just put the Highs right around average.


This June we didn't have any Highs which hit 30°C, but we did have 11 days at 25°C, and 25 days at 20°C. That meant this was a pretty warm June, although not quite as warm as 2016 or 2002.

One thing to note is that the last 4 June's have all been more summer-like than typical. Since 2015 June has averaged 10 days at 25°C, but for 2003-2014 we were down at only 4 25°C days. And since 2015 June has averaged 24 days at 20°C compared to 16 days for 2003-2014.

And last month I'd said: "Normally June is warmer than May, but that will be a tough trick to pull off this year." And June might have actually pulled it off, depending on how you count:


May had 1 day which hit 30°C and 13 days at 25°C, and that beats June's score of 0 and 11. But June's 25 days at 20°C beats May's 23, and the average High for June was 23.1°C compared to 22.3°C.

Either way though, 2018's extremely warm May was followed by a very warm June. May and June are often iffy, shoulder-season months, but in 2018 they were basically 2 bonus months of summer to make up for the very late spring.


Low Temperatures

For the Low temperatures we did set one all-time warmest Low on June 25th at 17.4°C, and then 4 other since-1996 records.

The range of Low temperatures in June is very tight - from about 5°C up to 17°C - and so even our colder nights this month stayed pretty close to the average.


And here again we can see how uniform (ie. orange) June Low temperatures are. This June we did have one night below 5°C, which is a little unusual. But our average Low of 11.2°C was still on the warm side of things, behind only 2006, 2016 and 2015.


Precipitation

With 76.2mm of rain at the International Airport and 62.2mm at Blatchford this June was right around the average of 72mm. It was also a little bit above the 57mm that we got last June.


This chart shows the number of days each month which recorded precipitation. This June the International had 11 days, which is a bit below the average of 14 days. But Blatchford was way down at 5 days, and it was the third month in a row that was well below the average.


July Temperatures

Looking ahead to July, May and June of 2018 really were quite July-like - we've already had a lot of 20°C and 25°C days in the last two months. July's average High will probably top May and June, but there's a chance that the number of warm days won't. And the unfortunate fact is that mid-late July is when our temperatures will start trending downward again.