Having read though this thread, I've noticed a number of people basing their opinions on varying eras of Edmonton climate.
I can only speak to the past 25 years (I moved here a few years after the tornado), but here is what I remember of the weather, and how it has changed through the years. Feel free to correct me if I have any of the years wrong, I'm bad with time frames. I have grouped them on general
1990-96: Winter weather (minus temperature and snow) beginning late Sept. or early Oct. Often 2 ft of snow by Halloween. Thaw/melt by mid Apr.-early May. Often heavy rain/thunderstorms from May-early July. Many cold snaps, often seeing one full month of below -25 weather, with often 2 weeks or more with low temperatures ranging from -30 to -45. Hot summers, often over 30C through July-mid August.
1997: When things began to change. This year saw warm weather (15-20C daytime highs) through to December 31. That evening the temperature fell to -20, and a blizzard dropped over a foot of snow. The following Winter lasted to mid-May but was quite cold through Jan./Feb.
1998-2004: Winter usually started later than years prior, excepting 97. First snowfalls often late Oct-early Nov. Temperatures in this time period often fluctuating between -20C and 15C causing multiple freeze/melt cycles. Snow often wouldn't stay until late Nov./early Dec. Reduced number of cold snaps . Thaws occurred late Apr.-mid May. Fewer large storms, though those that occurred were often more intense
2005-present: Much different than it was when I moved to Edmonton. First snowfall often not occurring until late Nov. Fewer and shorter periods of cold snaps, with often higher lows than previous years. Fewer severe cold periods during this time (I only remember 3 nights in the past 7 years of below -40). Less average rainfall during this period - though the past 2 years have seen much more than normal through May/June. Summers seeing fewer periods of oppressive heat (greater than 30C)
