Why the Prairies get more sun than the rest of Canada
Mountains play a big role in why Alberta, Saskatchewan see more sunshine on average than other provinces
CBC Alberta and Saskatchewan have teamed up for a new pilot series on weather and climate change on the Prairies. Meteorologist Christy Climenhaga will bring her expert voice to the conversation to help explain weather phenomena and climate change and how it impacts everyday life.
If you are looking to catch some rays in Canada, your best bet is to head to the Prairies.
Southern Saskatchewan and southeast Alberta lead the country in sunshine, with many communities in those provinces seeing more than 2,400 hours annually according to Environment and Climate Change Canada.
The rest of Alberta, Saskatchewan and Manitoba are not far behind, racking up over 2,000 hours per year.
To put that in perspective, some areas along the Pacific coast see only 1,200 to 1,400 hours of bright sunshine per year.
While some communities, such as Yellowknife, may individually see quite a bit of sun, the region as a whole is the bull's-eye for sunshine in the country.
The two provinces enjoy more hours of sun because, simply put, the prairie climate is drier.
Areas close to big bodies of water get much more cloud cover and precipitation with all of that moisture-rich air, such as the atmospheric river event we saw recently in B.C.
Edmonton sees an average of 446 millimetres of precipitation a year, with Calgary close behind at 419 millimetres. Regina and Saskatoon get 390 millimetres and 354 millimetres, respectively.
Those numbers pale in comparison to Vancouver, where it's normal to see 1,189 millimetres of precipitation in a year.
Without that consistent cloud cover and wet weather, the Prairies get a lot of sunshine.
That abundance of sun is the reason the Prairies are seeing a significant boost in a rapidly developing solar power industry.
- Saskatoon councillors support 2-megawatt solar farm project near Montgomery Place
- Cowessess unveils new solar project, aiming to become greenest First Nation in Canada
A number of large solar projects are already underway to meet this potential, including the Travers Solar Project in Lomond, Alta., and a proposed solar farm near the Edmonton International Airport.
Rain shadow effect
There are a number of reasons the Prairies are so dry, but at the centre, as in real estate, it's all about location.
The western Prairies are a long way from any significant source of moisture. The closest source is the Pacific Ocean, but that moisture has quite a journey to get to Alberta and Saskatchewan.
Though Pacific moisture can make it to the Prairies, it has to pass a big obstacle. That brings us to the second reason for the Prairies' sunny weather.
The western Prairies sit in what's called a rain shadow.
Looking at the topography of Canada, we see Alberta has the Coast Mountains and Rocky Mountains to the west and plains to the east. Moisture-laden air coming off the Pacific Ocean hits those mountain ranges and rises. As it rises, it cools, and we get condensation and rain or snow.
By the time that air descends on the lee side in Alberta, it is sapped of moisture.
Now, of course, Alberta and Saskatchewan do get rain, but rainfall trends on the Prairies differ from other areas of Canada, which brings us to the third reason for so much sunshine.
Fast-moving storms
The jet stream — the narrow band of fast-moving air in the upper atmosphere that directs our weather systems — often leaves the Prairies with a big ridge of high pressure.
Air in that high pressure sinks and usually means little to no cloud cover, giving Alberta and Saskatchewan that beautiful blue sky they are known for.
When storms do happen, they are fast-moving. Prairie weather systems such as Alberta clippers or Colorado lows can generate a lot of water but then head on their way within a day or two.
The other big summer storms on the Prairies are convective thunderstorms, which usually come in the evening after a relatively sunny day, so though we do get those impressive cloud formations, most of the day still counts as a sunny one.
How could climate change impact sunshine?
As our climate warms, you may be thinking, "OK more evaporation, more moisture in the air, that means more clouds and less sun."
That may not be the case, however.
As our air warms, our relationship with relative humidity changes as well.
So even though we may have more water vapour in the air, because the air itself is warmer, the relative humidity may be comparable to what it is now.
That means we could still have the same amount of cloud cover, but when those storms do hit, we could see more precipitation because there is more water present.
So, more rain or snow, but the same amount of sun, even though that may sound counterintuitive.
Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled Our Changing Planet to show and explain the effects of climate change and what is being done about it.
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