That's a tricky question! You're looking for a planet with an average temperature of 45 degrees Fahrenheit, but the answer depends on how you define "average" and which part of the planet you're talking about.

Here's why:

* Earth's Average Temperature: Earth's average temperature is closer to 59 degrees Fahrenheit.

* Variations Across Planets: Planets have different climates and temperatures depending on their distance from the sun, their atmosphere, and other factors. For example, Mars has a much colder average temperature than Earth.

* Daily and Seasonal Fluctuations: Temperatures on planets fluctuate significantly throughout the day and across different seasons.

Therefore, there's no single planet that consistently has an average temperature of 45 degrees Fahrenheit.

To get a more specific answer, you'd need to specify:

* Which part of the planet: Are you looking at the surface temperature, the temperature of the atmosphere, or a specific region?

* Timeframe: Do you want the average over a year, a season, or a single day?

Let me know if you have more information, and I can help you find the right planet!