Back to basics: Temperature truisms

Author: 
October 6, 2016

We’ve been going Beyond the Data for a year and a half now (time flies!). Sometimes, on a long journey, it’s good to revisit the basics. What got us here?

That’s the theme for this edition. We’re going old school, and just look at some good old climatology adages and truisms, through the lens of a sturdy, reliable warhorse of a dataset.

One question that we get here at NCEI’s Center for Weather and Climate, more so than you might think, are questions about superlatives. “What is the hottest place in America?” and so on. I call these the “Mostest Questions.”

To respond to these recurring questions, we set up a handy viewer that helps describe just that. Today’s edition of Beyond the Data will walk through the tool’s output for temperature, focusing on the “why” behind the answers to these Mostest Questions.

Before we start: Tips for do-it-yourselfers

If you want to explore the data yourself, have at it. Here’re a few things to know before you explore:

  • The values come from NCEI’s Normals dataset, the same project that provides the values you may hear on the evening news (“Today’s normal high in Tulsa is …”).

  • Not every location in America is represented in the data set. It’s limited to about 450 stations for which we have the most comprehensive data.

  • There’s an option to “filter by distance.” This provides some geographic flexibility on the output (“gee, the 20 coldest places in America are in the same part of Alaska”). For the discussions below, I left the filter at the default “don’t give me stations that are within 20 miles of each other” setting.

First look: Warmest and coldest places in America

Okay, the obvious questions: what are the warmest and coldest places, year-round, in the country?

Warmest Places in the United States

(average annual temperature)

 

Coldest Places in the United States

(average annual temperature)

1

Key West Naval Air Station

FL

78.1°F

 

1

Deadhorse Airport

AK

11.5°F

2

Honolulu Int’l Airport

HI

77.7°F

 

2

Barrow | Post-Rogers Airport

AK

11.8°F

2

Ft. Lauderdale | Hollywood Airport

FL

77.7°F

 

3

Kotzebue | Ralph Wein Airport

AK

22.9°F

4

Miami Int’l Airport

FL

77.2°F

 

4

Bettles Airport

AK

23.5°F

5

Yuma Airport

AZ

76.0°F

 

4

Northway Airport

AK

23.5°F

6

Kahului Airport

HI

75.9°F

 

6

Nome Municipal Airport

AK

27.4°F

7

Lihue Airport

HI

75.8°F

 

6

Mt. Washington

NH

27.4°F

8

McAllen | Miller Int’l Airport

TX

75.6°F

 

6

McGrath Airport

AK

27.4°F

9

West Palm Beach Int’l Airport

FL

75.4°F

 

9

Fairbanks Int’l Airport

AK

27.7°F

10

Ft. Myers | Page Field

FL

75.1°F

 

10

Gulkana Airport

AK

28.2°F

10

Phoenix | Sky Harbor Int’l Airport

AZ

75.1°F

         

No surprises, right? The warmest places are in the south and the coldest places are in Alaska. This really underscores our first climate adage of the day: All else being equal, places closer to the equator are warmer and places closer to the poles are cooler. The underlying reason is straightforward: over the course of a year, the equator catches more of the sun’s energy than the poles.

Key West, FL. Southern point marker (Photo)

This marker at the Southernmost point of Key West, Florida, reads "90 miles to Cuba." Taken on November 6, 2008. Photo courtesy Daniel Schwen via Wikimedia Commons. Used under a CC license.

Anyway, on to our next - wait, what? The coldest aren’t all in Alaska? Oh, that’s right. There’s Mt. Washington, New Hampshire, which reminds of us a climate second adage: All else being equal, places at higher elevation are cooler, and places at lower elevation are warmer. What’s the underlying physics behind this? It’s simple: the atmosphere - at least the bottom two-thirds or so of it - cools with height. Mt. Washington combines elements of the first and second adages to sneak its way onto the list.

Triple digits and frequent freezers

Another variation of the Mostest questions involve how often a place gets really hot or really cold. One way to examine that is by counting the number of days each year a place reaches triple digits, or on the other extreme, drops below freezing. We’ve listed the top ten of each below. For the cold list, we’ve excluded Alaska to explore some details in the CONUS.

Most days-per-year in triple digits
(highs > 100°F)

United States

 

Most days-per-year below freezing
(lows < 32°F)

Contiguous United States

1

Yuma Airport

AZ

116.7

 

1

Big Piney | Marbleton Airport

WY

250.6

2

Phoenix | Sky Harbor Int’l Airport

AZ

103.3

 

2

Mt. Washington

NH

233.8

3

Las Vegas | McCarran Airport

NV

69.7

 

3

Alamosa | San Luis Airport

CO

223.1

4

Tucson Int’l Airport

AZ

52.1

 

4

Craig | Moffat County Airport

CO

218.3

5

Mercury | Desert Rock Airport

NV

34.2

 

5

Meacham

OR

214.5

6

Redding Municipal Airport

CA

32.1

 

6

Ely | Yelland Field Airport

NV

211.1

6

Lancaster | Wm. J. Fox Field

CA

32.1

 

7

Hibbing | Chisholm-Hibbing Airport

MN

208.9

8

Fresno | Yosemite Int’l Airport

CA

31.7

 

8

Burns Municipal Airport

OR

200.4

9

Red Bluff Municipal Airport

CA

26.8

 

9

International Falls Int’l Airport

MN

198.2

10

McAllen | Miller Int’l Airport

TX

26.2

 

10

Flagstaff | Pulliam Airport

AZ

196.9

Again, looks like southern places are warm and northern are cold. Wait, Redding, California has the sixth-most number of days over 100F? What? It was 99th in the "warmest places in America" list. Flagstaff, Arizona makes the list of frequent freezers? Looks like we may need to tag a few more truisms to explain these.

The triple-digit list emphasizes the following adage: When the sun is high, and the ground is dry, it gets hot. Redding, like most of California, and much of the Southwest, has very dry summers. It’s no coincidence that the triple-digit list is chock full of places with dry summers.

The frequent-freezer list evokes the first two truisms about temperature, and Flagstaff is certainly cool thanks to its elevation, but it also conjures up an additional adage: All else being equal, coastal places don’t experience the temperature extremes of inland places. The oceans have a moderating effect, while inland places will exercise more of the thermometer over the course of a year.

Thanks, see you soon!

Thanks for going Beyond the Data. We’ll pick up with the precipitation-and-snow versions of these climate adages in a future issue.