Monday, March 19, 2012

Thunderstorms mark fitting end to warmest March day on record..

Golf courses in full swing in
Winnipeg - March 18 2012
(Winnipeg Free Press photo)
The earliest thunderstorm on record in Winnipeg (since 1953) marked a fitting end to a summerlike final day of winter over the Red River valley.. as record breaking temperatures soared into the 20s along with gusty southerly winds and summer like humidity. In Winnipeg, the temperature peaked at 23.7C Monday afternoon, the warmest March day in the city since records began 140 years ago in 1872. The reading beats the previous warmest March day of 23.3C set over 65 years ago on March 27 1946. It was also Winnipeg's 5th consecutive daily record high, and the 7th in the past 9 days since this historic warm spell began on March 11th. The day also established a new record high minimum temperature for March, with a low of +13.3C at YWG airport.. the only time on record with a March low temperature in the double digits (previous warmest low was +7.8C on March 25 1945.)  In addition, the day featured summerlike humidity with dewpoints of 16C much of the afternoon, with a peak HUMIDEX reading of 28C at 3 pm in  the afternoon. These likely represent the highest such values ever recorded in March in Winnipeg.

List of record highs in Winnipeg : Mar 11 - 22, 2012

Date... REC HIGH (year) - Winnipeg Airport (data since 1872)

Sun 11 ..... 12.8C (2012) (prev 12.5C 1981)
Mon 12 ..... 9.7C (2012) (prev 7.2C 1922)
Tue 13 ..... 12.2C (1902) (11.7C 2012)
Wed 14 .... 11.4C (1981) (10.2C 2012)
Thu 15 ..... 14.4C (2012) (prev 11.1C 1927)
Fri 16 ...... 19.9C (2012) (prev 12.4C 1981)
Sat 17 ...... 19.2C (2012) (prev 12.8C 1938)
Sun 18 ..... 20.9C (2012) (prev 14.4C 1910) *earliest 20C reading on record*
Mon 19 .... 23.7C (2012) (prev 18.9C 1938) *new all time March maximum*
Thu 22 .... 21.7C (2012) (prev 18.3C 1878)

Temperature graph from my
weather station in Charleswood
March 19 2012
This warm spell has been one for the record books. Between March 11th-22nd, Winnipeg set 8 new record highs, including 3 days above 20C. In the previous 140 years of records, the 20C mark has been reached on only 3 occasions in March in Winnipeg (once each in 1910, 1938 and 1946). In other words, it took only 5 days during this warm spell to match what took 140 years to accomplish. Truly extraordinary. The warm spell has shattered records for March warmth throughout southern MB, the US plains, Great Lakes and eastern North America both in terms of extremes and duration. See blog entries from Jeff Masters, Chris Burt and A Weather Moment for more insight into this memorable weather event.


  1. Recall Winnipeg set an all time monthly high just last October (31C), now March (24C). 9 consecutive months above normal since last July.

    As the Buffalo Springfield song goes..

    "There's something happening here.. what it is ain't exactly clear.."

  2. I ended up with 10.4 mm of rain with a max rainfall rate of 155.6 mm/hr at 8:33 pm in NE Transcona. Not bad for March!

  3. Thanks Chris.. 15 mm at my place between 7:45 and 8:15 pm with a peak rate of 135 mm/hr at 8 pm. I left work thinking that the main activity would go to our northwest, but I drove into a menacing dark sky to the west with torrential rain by the time I hit Assiniboine Forest. Cars were crawling on Grant because the rain was so heavy. Torrential rain in March.. never thought I'd see that in Winnipeg.

  4. Rob!

    Another record broken. Warmest overnight low ever for March.

    Warmest day, warmest night ever and heavy thunderstorms all in one day. I'm exhausted!!!

  5. congrats on your record!

  6. Is 14C a record for today.

  7. 13.9 C is the record today. You never know ,we might break that one with a SW winds today!!

  8. We were at 13.5C just after midnight, so we already came very close to today's record. 925 mb temperatures are forecast to be 7C this afternoon, which would give us a high around 13C. But with enough sunshine and a favourable southwest wind, we could top the 14C mark again. Why not? Let's go for 6 in a row! (and 8 in the past 10 days!)

    Dan.. yes, it's been an amazing run, with a summerlike end to winter. I sure hope we don't pay for it with a winter like end to summer! :)

  9. And hits on your blog, did they top 5000 or just another record lol

  10. We walked out from our swimming event at 8:00 PM yesterday at the UM. A shower was falling and by the time we reached the car it was raining. By the time we reached Pembina Highway it was coming down in buckets. Traffic lights were out and large parts of the city were in darkness. Haven't seen such a downpour in a long time. It will be good for settling the dust.

  11. For anyone who's interested, yesterday evening's storm was indeed the earliest thunderstorm on record in Winnipeg since 1953. There've only been four times thunderstorms have been recorded in March at all in the last 59 years (the others being 28th March 1960, 29th March 1999, and 27th 2004).

    Incidentally, the three latest thunderstorms recorded at the airport since '53 are, in order, 5th December 1966 (which, weirdly, was also accompanied by freezing rain and snow pellets), 2nd December 1982, and 1st November 2000. :)

  12. Anonymous.. Thanks for those stats. Very interesting. I don't think we've ever seen dewpoints as high as the past two days at this time of year which certainly helped get those record early thunderstorms.

  13. Check out Windsor today! A temperature of 27 and a humidex of 30!!! Is today the first day of spring or the first day of summer?!

    Question: has any place in Canada recorded a 30+ humidex in March before?

  14. Andy,

    Windsor did record a humidexes of 30C and 31C on March 26th and 27th, 2007 repectively.

  15. Awesome, thanks Anon. I wonder if this would be the earlier 30 reading...
    Windsor...the next best thing to a tropical resort!

  16. You've obviously never been to Windsor :)

  17. I think it is the earliest 30C humidex ever recorded in Canada.

  18. Official temperature was 27.0C in both Windsor and Collingwood, Ontario.

    That's the highest temperature this year in Canada

    Now 7th straight 20C+ days in Windsor... MIND-BOGGLING March heat wave.

  19. Rob and everyone~

    Today's Jeff Masters weather underground blog is a must read

    Make sure you read the part about Chicago and Lake Michagan. UNREAL!

    Looks like we will get a chance of more records here in the next few days :)

  20. Rob!

    How are we in terms on the mean March temperture now???

    Are we close to the warmest March of all time??

  21. Talked about it on my blog, but thought I'd mention that it's looking like we'll break more records tomorrow and Friday, with an off-chance we'll re-set the hottest day in March record on Friday.

    Unreal weather.

  22. Top 4 warmest Marches in Winnipeg (since 1872)

    1878 1.6
    1910 1.2
    1973 0.5
    2000 -0.1

    As of the 20th, Winnipeg's average so far this March was +0.4C, but based on temperatures the rest of the week, we'll be near +2.0C by Friday. We cool down over the weekend, but looks like we rebound above normal again next week.. so barring any change to a much colder pattern next week, March 2012 will likely be our warmest March on record.

  23. Humidex of 32C in Windsor...

    Absolutely unreal!!! That is the warmest humidex recorded in Canadian history in the month of March!!!

  24. Every day brings more jaw-dropping records.

    Grand Rapids, MI sitting at 31 C right now (this is *not* the humidex!) and expecting a high of 33 C. OMG. Sometimes, we go entire summers here in Saskatoon without witnessing 33 C.
    Lansing and Traverse City, MI also above 30 C.Actually, a wide swath of southern MI is over 30 C.

  25. I didn't think it was possible to hit the 90F mark in Michigan in March.. unreal.