Kelowna IS Semi-Arid?

[Glacier]

Despite the commonly believed fallacy to the contrary, there are no deserts in BC, and the semi-arid zone is far smaller than we are lead to believe. Interestingly, there are several semi-arid locales like Osoyoos and Kamloops, but Kelowna is too wet to be classified as such. The correct classification for Kelowna is: "Humid Continental" climate.

Here are a few of the semi-arid cities in Canada (from most arid to least):

Spences Bridge
Medicine Hat
Kamloops
Osoyoos
Oliver
Keremeos
Lethbridge

Here are cities that are on the cusp of being semi-arid (most arid to least):

Lillooet
Summerland
Penticton

Here are cities that are too wet to be semi-arid (most arid to least):

Merritt
Calgary
Wineglass Ranch (near Williams Lake)
Peachland
Hedley
Kelowna
Princeton
Cranbrook
Vernon
Grand Forks
100 Mile House
Regina
Lytton

[1] Köppen climate classification
[2] http://en.wikipedia.org/wiki/Kelowna#Ge ... nd_climate

[gman313]

And your point would be?

[Fancy]

Thanks for posting that Glacier. I've often heard "semi-desert" in describing this area. With all the orchards and vineyards, I didn't think that accurate.

[Cumungala]

I CANT believe Lillooet is only on the cusp of being semi arid!! Some areas near Lillooet get less than 50mm of rain per year. I passed through Lillooet during the summer a few years ago, and I thought I was going to die. It was deathly hot. Im not surprised Cranbrook made the list. They have a climate similar to here, despite the fact that they are almost 1km above sea level. I am surprised Trail didnt at least make the "too wet for semi arid" list. Their highest temperature is almost 42 degrees, but they get a bit more rain than the other towns listed. Salmon Arm should have made the "too wet for semi arid" list also.

Im not surprised we arent considered semi arid. We get a considerable amount more rain and snow than those towns on the semi arid list. We actually get more snow then Medicine Hat and Lethbridge!!

[Otter]

Hmm...when I took Geography many moons ago, we were told that the Okanagan was the most northerly dry-land desert in North America. And since I graduated since the dinosauers died, I don't think that could have changed.

Where did you get your info from? If it's a website, could you please post the URL?

[OREZ]

Interesting, Glacier.

I'm actually a little surprised that Kamloops is considered semi-arid, I have some family members there and I knew it was dry but didn't think it was that much dryer than here. Is the designation based purely on precipitation or are there other factors considered as well?

[LoneWolf_53]

Thanks for posting that Glacier. I've often heard "semi-desert" in describing this area. With all the orchards and vineyards, I didn't think that accurate.

Turn off all the irrigation and see how many orchards stand up to the test.

Cacti definition is listed as....... "Any succulent plant of the family Cactaceae native chiefly to arid regions of the New World and usually having spines."


Take yourself a walk around the area like Knox Mountain Park for example and you'll quickly come to realize just how often you'll notice cacti when you are looking for them specifically.

Sure sometimes we get wetter times but on average without irrigation we wouldn't grow too much successfully and in so far as that goes I've seen the New Mexico desert flood on a number of occasions too but it's still desert regardless.

[Otter]

Hmm...when I took Geography many moons ago, we were told that the Okanagan was the most northerly dry-land desert in North America. And since I graduated since the dinosauers died, I don't think that could have changed.

Where did you get your info from? If it's a website, could you please post the URL?

Oh, I see you got the info from Wikipedia. Well, it must be true then. We all know what a truly reliable site that is.

[StraitTalk]

Hmm...when I took Geography many moons ago, we were told that the Okanagan was the most northerly dry-land desert in North America. And since I graduated since the dinosauers died, I don't think that could have changed.

Where did you get your info from? If it's a website, could you please post the URL?

Oh, I see you got the info from Wikipedia. Well, it must be true then. We all know what a truly reliable site that is.

Open your eyes. It's all sourced.

[strwbrrydvl]

Interesting.
I knew Kelowna was far from being a desert but I thought that Osoyoos was.
Learn something new everyday.

[chrisv]

Thanks for the info

[Glacier]

Interesting, Glacier.

I'm actually a little surprised that Kamloops is considered semi-arid, I have some family members there and I knew it was dry but didn't think it was that much dryer than here. Is the designation based purely on precipitation or are there other factors considered as well?

Hi OREZ, I have't noticed you around Castanet for while. Welcome back; I always apreciated your consolatory demeanor amidst all the ciaos. But I digress.

Classifying arid/semi-arid zones is based on potential evapotranspiration with the Köppen climate classification being the most commonly accepted classification method:

1)First determine the precipitation threshold = Average annual temperature X 20 +

280 if 70% of precipitation occurs in warm months OR
140 if 30% to 70% of precipitation occurs during warm months OR
0 if <30% occurs during warm months

2) If annual average precipitation is less than 50% of the precipitation threshold then the Climate is Arid.
3) If annual average precipitation is between 50% and 100% of the threshold then the Climate is Semi-arid.

All BC interior cities (except Lytton) have evenly distributed precipitation between the warm and cold months. Lytton gets almost all of its precipitation during the cold months, which is opposite of Alberta cities like Calgary and Lethbridge that obtain over 70% of their precipitation during the warm months. Hence the reason Lethbridge is considered Semi-arid and Kelowna is not, despite similar annual precipitation at both cities.

As for Kamloops compared to Kelowna, Kelowna is about 36% wetter. Similarily, Osoyoos gets about 14% more precipitation than Kamloops.

All these numbers can easily be varified at Environment Canada.

SUMMARY: Aridity is based on annual temperature, total precipitation, and the % of total precipitation occurring between April to September.

I hope that answers your queries.

ETA: I miscalculated Regina in the opening post; I will correct.

[omisimaw]

totally disagree....
http://www.vancouverisland.com/regions/towns/?townID=3441

[Woodenhead]

Yeah, I disagree, too, but I think it's mostly because it's very localized. The cactii growing in certain areas is proof enough for me that there are definitely semi-arid pockets here, at the very least.

[Cumungala]

I checked the Canadian Climate Normals and here's what I came up with. The rain and snow is what each place gets in an average year, and the temperature is the highest ever recorded there.

Spences Bridge ~the driest of the dry: 239mm of rain and JUST 29.5cm of snow. Highest Temp 42.5
Medicine Hat: 249.3mm of rain and 95.2cm of snow. Highest Temp 42.2
Kamloops (Airport): 217mm of rain and 75cm of snow. Highest Temp 40.6
Osoyoos (West): 267mm of rain and 49.6cm of snow. Highest Temp 39.5
Oliver: 280mm of rain and 46.9cm of snow. Highest Temp 42.8
Keremeos: 256mm of rain and 66.8cm of snow. Highest Temp 39.5
Lethbridge: 271.1mm of rain and 130.5cm of snow. Highest Temp 39.4
PLACES THAT GET MORE RAIN THAN KELOWNA: 0 SNOW: 1

Lillooet (BCHPA): 297mm of rain and 32.4cm of snow. Highest Temp 41.5
Summerland: 261.2mm of rain and 67.9cm of snow. Highest Temp 40
Penticton: 279.6mm of rain and 67.2cm of snow. Highest Temp 40.6
PLACES THAT GET MORE RAIN THAN KELOWNA: 0 SNOW: 0

Merritt: 238.9mm of rain and 83.3cm of snow. Highest Temp 39.5
Calgary (Airport): 320.6mm of rain and 126.7cm of snow. Highest Temp 36.1
Wineglass Ranch: 249mm of rain and 65.2cm of snow. Highest Temp 38.5
Peachland: 310.6mm of rain and 90.6cm of snow. Highest Temp 37.8
Hedley: 297.6mm of rain and 79.3cm of snow. Highest Temp 41.1
Kelowna: 298mm of rain and 101.8cm of snow. Highest Temp 39.5
Princeton: 239.2mm of rain and 146.8cm of snow. Highest Temp 41.7
Cranbrook (City): 274.4mm of rain and 126.8cm of snow. Highest Temp 36
Vernon: 308mm of rain and 102.9cm of snow. Highest Temp 38.5
Grand Forks: 391mm of rain and 118.7cm of snow. Highest Temp 42.2
100 Mile House: 294.3mm of rain and 159cm of snow. Highest Temp 36
Regina (CDA): 296mm of rain and 83.1cm of snow. Highest Temp 43.9!!!
Lytton: 338mm of rain and 117.4cm of snow!!! Highest Temp 42.2
PLACES THAT GET MORE RAIN THAN KELOWNA: 5 SNOW: 7

I cannot believe Lytton gets that much precipitation!! Ive tried to believe it, but I cant. I dont really care that Kelowna isnt considered semi arid. We still get plenty of hot days in the summer and we get just the right amount of rain. Im glad I dont live in Spences Bridge or Ashcroft where you cant even go outside some days and watering restrictions are are a familiar occurance.