18 hours
The average temperature on Mercury can vary dramatically, ranging from about -280°F (-173°C) at night to around 800°F (427°C) during the day due to its thin atmosphere and lack of significant heat retention.
The average surface temperature on Mercury is around 700 K (426.85°C). However, temperatures can vary greatly depending on the location and time of day due to Mercury's lack of atmosphere to regulate heat.
On Mercury, just like on Earth and on every other planet, the sun is rising somewhere every minute of every day.
350 degrees in the day time 170 degrees in the night time
Mercury
No, one Mercury day is equal to 58.6 Earth days
Mercury is 0.387 AU from the Sun. Bonus fact: The average temperature on Mercury during the day is 662ºF! Here's a website where you can learn more about the planets
It is at least 250 to 300 degrease
The average temperature on Mercury ranges from about 800 degrees Fahrenheit (430 degrees Celsius) during the day to -290 degrees Fahrenheit (-180 degrees Celsius) at night. Mercury's thin atmosphere does not retain heat well, leading to extreme temperature variations between day and night.
I think the planet you are thinking of is Mercury.
Mercury's solar day is about 176 Earth days. That's the time taken by the Sun to complete one apparent trip round the sky.
Mercury's average temperature is around 440 Kelvin during the day and drops to around 100 Kelvin at night due to its thin atmosphere.