Every place I’ve ever lived the weathermen have repeated the old saw, “If you don’t like the weather here, just wait fifteen minutes and it’ll change.” Now I know some places, like Los Angeles, have fairly consistent weather, but where is the weather really the most extreme? Where does it go from freezing to 80F overnight, or from droughts to torrential flooding? There must be some geographical or environmental factors that would contribute to such variations.
I looked at some data on the Weather Channel’s website, and it looks like for many of the major US cities, the difference between the lowest and highest temperature ever recorded is always right around 104F. I expected there to be more variation between cities.
Any real data would be appreciated, but I’ll entertain rampant speculation too.
OK, here’s some rampant speculation for you: I’ll guess that it is in a dry inland clime. Water holds heat and damps out rapid temperature variations, so dry means bigger swings. It’s not unusual, for example, for it to hit 100 F in the summer in North Dakota, but also not unusual to go way below zero in the winter.
This is an excellent summation of a principle known to we geographer types as “continentality,” or “oceanic temperature moderation.” Essentially, the closer you are to an ocean, the less extreme your weather will be. Thus, Barrow, Alaska, even though it’s on the extreme northern edge of Alaska, doesn’t have the brutal cold you’ll find further inland (it also helps that there’s a warmish current running off the coast there.) Other examples abound. The UK has a relatively moderate climate in spite of its latitude (51 degrees north or so.) Compare “cool and rainy” to the climate of Calgary, Alberta at 51.5 degrees north. Their climate is also affected by a warm current, adding even more of a moderating effect (as well as a warm source of moisture for all that famous British rain!)
Basically, the further you go inland (away from oceans. Lakes don’t have as much of an effect, if any. In fact, sometimes they make the weather worse. Just ask folks in New York’s snow belt,) the more extreme temperature swings you’ll have.
Elevation also has a strong impact, of course.
All that said, I don’t know where the most extreme summer/winter high/low temperature change has occurred, but the most extreme 24-hour change occurred in Browning, Montana in 1916, when the temperature fell from 44 degrees F to -56 degrees F in 24 hours…a 11 degree difference.
Mt Washington has been called this, IIRC it still has the record of the highest wind speed recorded, somehting like 200mph+ before the darn thing that measures the speed broke.
[hijack] Re: Mt. Washington winds – I remember seeing a video clip of a researcher at a Mt. Washington weather station trying to cross a rooftop observatory in ridiculously high winds. He was pretty much blown back into the building. Does anyone know of this clip? Could you supply a link? [/hijack]
Fairbanks, AK is a dry, inland area. Temperatures can swing from 90F+ in summer to -60+F in winter. This doesn’t happen overnight, of course, but 1-2 day swings in the winter from 30 above to 40 below are common.
Most northern areas can beat this. In New England, highest-ever temps are mostly around or just over 100F. Areas of NH, VT and ME see -25 most winters, and -40 perhaps once a decade.
As noted, the summit of Mt. Washington has some claim to the most extreme weather. It has to do with jetstream winds touching down there - peak measured gust was over 230mph. In January, I heard a report of -47F with wind of 82 gusting to 95mph. On a nice summer day you might find mid-seventies, and now and then, low winds.
I think it was of Bill Bryson’s books which mentioned that you could fry an egg on your car in Death Valley, then drive twenty minutes into the mountains and freeze it in a snowbank.
Ogre, big lakes, ones too big to normally freeze over, will moderate climate in the same way oceans will. Look at the difference between the climates of Toronto and Montréal, for instance. These two cities are only 400 or 500 km apart, and close in latitide, but winter temperatures in Montréal are always around 5-10 Celsius degrees colder than those in Toronto. The difference? Montréal has the inland climate of other mid-continental places on its latitude, but Toronto in next to Lake Ontario, and its cold temperatures are moderated by the lake.
The same effect takes place in the summer. Areas next to the lake are significantly cooler than those a few kilometres inland. For some reason, I’m guessing due to urban heating, the lake’s moderation of heat does not seem to be as strong as the moderation of cold.
Of course, even Montréal’s climate extremes pale compared to those of, say Saskatchewan.
Highest I recall was +41 or 42. It was definitely over 40. Rather blicky, what with having no a/c. 35 would be a significant hot spell, but isn’t really uncommon. I can only recall three or so occasions of hitting 39 (100F) though.
Coldest would be in the vicinity of -46 or 47. Heck, we had a -45.6 or something just a couple weeks ago. It’s not uncommon to get a couple nights of -45 per winter, but it’s quite rare to get anything much colder, leastways round here - Fond du Lac and Stony Rapids would be another story in that regard, of course.
