QUESTION:
How can I get an hourly listing of temperatures covering a 24 hour 
period on Mars? What is the average temperature?

ANSWER from Bruce Jakosky on May 13, 1997:
Because Mars is farther from the Sun than is the Earth, it receives less
light from the Sun and it is colder.  The average surface temperature on
Mars is about 220 Kelvin (-53 degrees Celsius, or -63 degrees Fahrenheit).
During the middle of the day at the equator, however, the temperature of the
surface can rise to above the melting point of ice (273 Kelvin, 0 degrees
Celsius, or 32 degrees Fahrenheit); it occasionally will get as warm as
a pleasant spring day on Earth.  Of course, during the long polar night,
when the Sun doesn't rise for half a year, the temperature can drop to
as low as 140 Kelvin (-133 degrees Celsius, or -207 degrees Fahrenheit).

ANSWER from Jim Murphy on May 28, 1997:

    VIKING LANDER 1 MEASURED NEAR SURFACE AIR TEMPERATURE (KELVIN)

    SOL #589, Ls=60 (which corresponds seasonally to May 20th)
    (The temperatures below were measured at the Viking lander 1
     site on the 589th day of the mission, which was late March, 1978,
     I think.  Viking Lander 1 set down on the martian surface at
     22.5 degrees North latitude, 48.0 degrees West longitude.
     Let me know if you have any questions about the data in this file.
     I'll send another response in a day or two listing a URL at
     which Viking lander can be otained.     JRM  05/27/97)


       LOCAL TIME    AIR TEMPERATURE
     AT THE VL1 SITE   (KELVIN)

         HR:MIN

         ------         -------

          0:28           191.8
          1:26    	 189.3
          2:24  	 188.4
          3:21    	 186.9
          4:19    	 185.7
          5:17    	 185.1
          6:15    	 188.1
          7:12    	 197.9
          8:10    	 210.3
          9:08    	 219.7
         10:05    	 225.2
         11:03    	 229.9
         12:01    	 234.9
         12:59    	 237.8
         13:56    	 238.9
         14:54    	 238.5
         15:52    	 237.5
         16:49    	 234.1
         17:47    	 224.5
         18:45    	 214.1
         19:43    	 206.3
         20:40    	 202.9
         21:38    	 199.4
         22:36    	 197.4
         23:33    	 196.7


    For the purpose of creating this file, I have divided the martian SOL
  (day), which is 88775.2 seconds in duration, into 24 'hours' (each of which
  is 61.6 minutes in length).  The data values represent averages over 59
  minute intervals (thus there are 25 temperature values during the sol).
    The standard processing procedure for the Viking meteorology data was
  this 25 'bins' per sol.  For Mars Pathfinder, of which I am a member of
  the Meteorology Science Team, we have decided to collect data in 3-minute
  averaging intervals spaced at approximately 28 minute intervals through
  the sol;  this will provide 51 time averaged values of wind, pressure, and
  temperature during a sol.   So, if you happen to see some Pathfinder
  meteorology data following our (hopefully!) successful landing on July 4th
  (37 days from now!), you can compare it to the VL1 data contained in this
  file.   Pathfinder will be landing at the seasonal equivalent of August 24th
  (Ls=143, where Ls is a seasonal indicator, since months have not been defined
  for Mars).

    Good luck with your lab.

   Jim Murphy						27 May, 1997
   NASA Ames Research Center / San Jose State Univ. Foundation
   Mars Pathfinder Meteorology Science Team

ANSWER from Mary Urquhart on May 28, 1997:

Sandy,

Since you didn't specify if you wanted surface or atmospheric
temperatures, we are sending a little of both for the same spring day on
Mars. 

You're correct that data is more interesting to work with, but frequently
we don't have the data we want. For example there are no direct
measurements of ground temperature on Mars. But ground temperatures are
important in understanding the physical structure of the soil and the
behavior of CO2 and water ices. So we resort to computer models to
calculate the information we need to address these scientific questions. 

Also, you'll notice the air and ground temperatures are not the same.  The
surface cools off at night and heats during the day more efficiently than
the air. This effect is similar to sand at the beach being unbearably hot
during a mild, but sunny, summer day. 

                    - Mike Mellon and Mary Urquhart
                      Laboratory for Atmospheric and Space Physics
                      University of Colorado at Boulder

-------------------------------------------------------------------
For Viking Lander 2 at 48 degrees North latitude
  (Earth equivalent: late April) 
  All Temperatures in units of Kelvin = Celsius + 273.16
-------------------------------------------------------------------
Model Ground Temperatures [Kelvin]:  mars day = 72, Ls = 35.04
At 1 hr intervals starting at midnight (a Mars day = 24.66 hours).

 185.6  183.9  182.4  181.0  179.7  185.7  196.9  209.9  
 222.7  234.1  243.2  249.6  253.0  253.6  251.4  246.4  
 238.9  228.9  216.9  205.1  199.1  195.0  191.8  189.2  

-------------------------------------------------------------------
Viking Lander 2 Air Temperature Data [Kelvin] (Mission Day 488) 
Measured at 25 intervals per martian day (about 59 minute intervals).

 194.25  193.20  191.55  188.83  187.86  186.20  189.59  199.37 
 210.04  224.91  221.87  224.17  225.44  226.97  232.17  234.82  
 235.92  234.94  231.52  222.87  211.58  206.09  202.25  199.25  
 196.17  
 
From Planetary Data System (PDS) at http://atmos.nmsu.edu/atmos-home.html
-------------------------------------------------------------------