Back Button

 
 
Soil Table 3: (Metric) Mean Earth Temperatures, 
Annual Soil Swing, and Phase Constants for U.S. Cities*

Note: The 'Phase Constant' represents the coldest day of the year. 
The warmest day of the year is approximately 6 months (~182 days) after To
Example:  January 1 = 1;  February 1 = 32;  March 1 = 60, etc.


 
State
City Tm (oC) As(oC) Coldest
Day of Year
To(Days)
(# 1-365)
Warmest
Day of Year
T1(Days)
(# 1-365)
AL
Birmingham
18.3
10.6
31
213
Montgomery
19.4
10.0
31
213
       
AR
Little Rock
17.8
11.7
32
214
              
AZ
Phoenix
22.8
12.8
33
215
Tucson
21.1
10.0
34
216
    
 
 
 
 
 
CA
Los Angeles
17.8
3.9
54
 236
Merced
20.0
13.9
33
 215
San Diego
17.8
3.9
54
 236
  
 
 
 
 
 
CO
Colorado Springs
10.6
11.7
36
 218
Denver
11.1
12.2
37
 219
Grand Junction
12.8
13.9
32
 214
    
 
 
 
 
 
DC
Washington
13.9
12.2
36
218
   
 
 
 
 
 
FL
Appalachio.
21.1
8.3
36
218
Jacksonville
21.7
7.8
32
214
           
State
City Tm (oC) As(oC) Coldest
Day of Year
To(Days)
(# 1-365)
Warmest
Day of Year
T1(Days)
(# 1-365)
 
 
 
 
 
 
GA
Atlanta
16.7
10.6
32
214
Augusta
18.3
10.0
30
212
Macon
19.4
9.4
33
215
   
 
 
 
 
 
IA
Des Moines
11.1
15.6
35
217
Sioux City
10.6
16.1
34
216
              
ID
Boise
11.7
11.7
34
216
Idaho Falls
7.8
12.8
34
216
 
 
 
 
 
 
IL
Chicago
10.6
13.9
37
219
E. St. Louis
13.9
13.3
34
216
Urbana
11.7
14.4
35
217
    
 
 
 
 
 
IN
Ft. Wayne
11.7
13.3
35
217
Indianapolis
12.8
13.3
34
216
South Bend
11.1
13.9
37
219
 
 
 
 
 
 
KS
Dodge City
13.9
13.9
35
217
Topeka
13.3
14.4
35
217
   
 
 
 
 
 
KY
Louisville
15.6
12.2
33
215

 
State
City Tm (oC) As(oC) Coldest
Day of Year
To(Days)
(# 1-365)
Warmest
Day of Year
T1(Days)
(# 1-365)
   
LA
Lake Charles
21.1
8.9
32
214
New Orleans
21.1
8.3
32
214
Shreveport
18.9
10.6
32
214
   
MA
Portland
8.9
12.2
39
221
Plymouth
10.6
11.7
43
225
    
 
 
 
 
 
MI
Battle Creek
10.0
13.3
35
217
Detroit
10.0
13.9
39
221
Sau St. Marie
5.6
14.4
40
222
    
 
 
 
 
 
MN
Duluth
5.0
15.6
37
219
Int. Fals
3.9
17.2
34
216
Minneapolis
8.3
16.1
35
217
    
 
 
 
 
 
MO
Columbia
13.9
13.3
35
217
Kansas City
14.4
14.4
35
217
Springfield
14.4
12.8
34
216
   
MS
Biloxi
21.1
9.4
32
214
Columbus
18.3
10.6
32
214
Jackson
19.4
10.0
31
213
   
MT
Billings
9.4
12.8
37
219
Great Falls
8.9
12.8
36
218
Missoula
7.8
11.7
32
217
           
State
City Tm (oC) As(oC) Coldest
Day of Year
To(Days)
(# 1-365)
Warmest
Day of Year
T1(Days)
(# 1-365)
    
 
 
 
 
 
NB
Grand Junction
11.1
15.0
35
217
Lincoln
11.7
15.6
34
216
N. Platte
10.6
14.4
35
217
   
NC
New Bern
18.3
9.4
35
217
Greensboro
15.6
11.1
31
213
              
ND
Bismark
6.7
17.2
33
215
Grand Forks
5.6
18.3
35
217
Williston
7.2
16.1
34
216
              
 NJ
Trenton
12.8
12.2
38
220
    
 
 
 
 
 
 NM
Albuquerque
15.0
12.2
31
213
Roswell
17.2
12.2
30
212
    
 
 
 
 
 
 NY
Albany
10.0
13.9
38
220
Binghamton
8.9
13.3
38
220
Niagara Falls
10.0
13.3
24
216
Syracuse
10.0
13.3
38
220
   
NV
Ely
8.3
12.2
35
217
Las Vegas
20.6
12.8
32
214
Winnemucca
11.1
12.2
33
215

 
 
State
City Tm (oC) As(oC) Coldest
Day of Year
To(Days)
(# 1-365)
Warmest
Day of Year
T1(Days)
(# 1-365)
OH
Akron
11.1
12.8
37
219
Columbus
12.8
12.2
34
216
Dayton
13.3
13.3
35
222
Toledo
10.6
13.9
36 
218
   
OK
Altus
18.3
13.3
33
215
Oklahoma City
16.7
12.8
34
216
Tulsa
16.7
12.8
34
216
    
 
 
 
 
 
OR
Astoria
11.7
5.0
45
227
Medford
12.8
9.4
34
216
Portland
12.2
7.2
37
219
   
PA
Middletown
12.8
12.8
35
217
Philadelphia
12.8
12.2
34
216
Pittsburg
11.1
12.8
36
218
Wilkes-Barre
11.1
12.8
36
218
   
SC
Charleston
18.9
8.9
32
214
Greenville
16.7
10.6
33
215
Sumpter
18.3
10.0
32
214
    
 
 
 
 
 
SD
Huron
8.3
16.7
35
217
Rapid City
10.0
13.9
38
220
           
State
City Tm (oC) As(oC) Coldest
Day of Year
To(Days)
(# 1-365)
Warmest
Day of Year
T1(Days)
(# 1-365)
              
TN
Bristol
15.0
11.1
32
214
Knoxville
16.1
11.7
31
213
Memphis
17.2
11.7
32
214
Nashville
15.6
11.7
32
214
   
TX
El Paso
18.9
11.1
28
210
Ft. Worth
20.0
11.7
34
216
Houston
21.7
8.9
33
215
San Antonio
22.2
8.9
32
214
    
 
 
 
 
 
UT
Salt Lake City
11.7
13.3
35
217 
   
VA
Norfolk
16.1
11.1
37
219
Richmond
15.6
10.6
33
215
Roanoke
15.0
11.1
33
215
   
VT
Burlington
7.8
14.4
37
219
   
WA
Moses Lake
11.7
12.8
29
211
Seattle
11.7
6.7
36
218
Spokane
9.4
11.7
32
214
              
WI
Green Bay
7.8
14.4
37
219
Madison
9.4
15.0
36
218
              
WV
Charleston
14.4
11.1
33
215
Elkins
11.1
11.1
32
214
            
WY
Casper
9.4
13.3
37
219
Cheyenne
8.9
11.7
39
221
Lander
7.8
13.3
38
220
Sheridan
8.9
13.3
35
217

 
*Adapted from Closed-Loop/Ground-Source Heat Pump Systems Installation Guide.  NRECA Research Project 86-1.  Oklahoma State University.  1988. and Perry, Robert H. and Chilton, Cecil H. Chemical Engineer's Handbook. 5th Ed. New York, McGraw Hill Book Company, 1973.

Back Button