Minus 60 degrees C
At the surface, the atmosphere presses down as hard as water 3,000 feet beneath Earth's ocean. The average temperature on Venus is 864 degrees Fahrenheit (462 degrees Celsius). Temperature changes slightly traveling through the atmosphere, growing cooler farther away from the surface. Lead would melt on the surface of the planet, where the temperature is around 872 F (467 C). Temperatures are cooler in the upper atmosphere, ranging from (minus 43 C) to (minus 173 C). Balmy all year-round. A barometer is used to measure air pressure. The average air pressure on Earth is 29.92 inches of mercury (or 1,013 millibars). This is more than 100 times Mars' average of 0.224 inches of mercury (7.5 millibars). Air pressure is not the same everywhere on Earth. One reason is because temperature varies from place to place. When air heats up, air molecules move faster, pushing each other away and causing air to expand. On Mars, the air is saturated (100% humidity) at night, but undersaturated during the day. This is because of the huge temperature difference between day and night. To demonstrate this: Take a clean, dry jar and place the lid on it. The temperature on Mars may reach a high of about 70 degrees Fahrenheit (20 degrees Celsius) at noon, at the equator in the summer, or a low of about -225 degrees Fahrenheit (-153 degrees Celsius) at the poles. On Mars, the air is saturated (100% humidity) at night, but undersaturated during the day. This is because of the huge temperature difference between day and night. To demonstrate this: Take a clean, dry jar and place the lid on it. This has a major influence on Mars’ climate. While the average temperature on Mars is about 218° K (-55° C, -67° F), Martian surface temperatures range widely from as little as 140° K (-133° C, -207° F) at the winter pole to almost 300° K (27° C, 80° F) on the dayside during summer. But Mars is a cold planet now; the average recorded temperature on Mars is -63° C (-81° F) with a maximum temperature of 20° C (68° F) and a minimum of -140° C (-220° F). The first spacecraft to visit Mars was Mariner 4 in 1965. Several others followed including the two Viking landers in 1976. Extreme differences. Mars's atmosphere is about 100 times thinner than Earth's. Without a thermal blanket, Mars can't retain any heat energy. On average, the temperature on Mars is about minus 80 degrees F (minus 60 degrees C). In winter, near the poles temperatures can get down to minus 195 degrees F (minus 125 degrees C). A summer day on Mars may get up to 70 degrees F (20 degrees C) near the equator, but at night the temperature can plummet to about minus 100 degrees F (minus 73 C) Mars: Mars’ average surface temperature is -55 °C, but the Red Planet also experiences some variability, with temperatures ranging as high as 20 °C at the equator during midday, to as low as -153 °C at the poles.  Mars' average surface temperature is -55 °C, but the Red Planet also experiences some variability, with temperatures ranging as high as 20 °C at the equator during midday, to as low as -153 °C at the poles.  The average pressure on the surface of Mars is only about 7 millibars (less than 1% of Earth’s), but it varies greatly with altitude from almost 9 millibars in the deepest basins to about 1 millibar at the top of Olympus Mons. But Mars is a cold planet now; the average recorded temperature on Mars is -63° C (-81° F) with a maximum temperature of 20° C (68° F) and a minimum of -140° C (-220° F). The first spacecraft to visit Mars was Mariner 4 in 1965. Several others followed including the two Viking landers in 1976. Differing in situ values have been reported for the average temperature on Mars, with a common value being −55 °C (218 K; −67 °F). Surface temperatures may reach a high of about 20 °C (293 K; 68 °F) at noon, at the equator, and a low of about −153 °C (120 K; −243 °F) at the poles. The climate of Mars has been an issue of scientific curiosity for centuries, not least because Mars is the only terrestrial planet whose surface can be directly observed in detail from the Earth with help from a telescope.
http://www.space.com/18526-venus-temperature.html http://www.quest.nasa.gov/aero/planetary/mars.html http://www.quest.nasa.gov/aero/planetary/mars.html http://marsnews.com/the-planet-mars http://www.space.com/16907-what-is-the-temperature-of-mars.html http://www.universetoday.com/35664/temperature-of-the-planets/ http://phys.org/news/2014-12-average-surface-temperature-planets-solar.html http://marsnews.com/the-planet-mars https://en.wikipedia.org/wiki/Climate_of_Mars
mars average surface temperature in celsius