Can someone explain this?

I'll try to keep this quick but simple.

It's not the suns direct rays that warm the air, it's the suns warming of the Earth's surface, that warms the air. The ground warms by absorbing the suns radiation, and then warms the air, through conduction. The air at the surface is warm, it then begins to rise, like you mentioned, heat rises, because it is less dense than the surrounding air. However, as air rises, it cools and expands. The air continues to cool as it rises, so by the time you are at the altitude of a mountaintop, the warm air that was heated by the sun at the surface, has risen and cooled, and expanded.

Of course there are other factors that go into the actual temperatures of mountains and sea-level areas - sometimes the mountains can be warmer than certain sea-level towns, but this is a generalization, canceling out all other factors.

The air is thinner at higher elevations. It is not always hotter at lower elevations, that is dependant on climatic and local weather conditions. Just think of valley's - or the fact that in lots of places you can't go to the beach in winter because it is too cold

Heat rises and then disperses. The effect of gaining elevation is equivalent to gaining latitude away from the equator.

The albedo (amount of lighter color of a body compared to darker pigmentation) of the terrain will determine the amount of heat it absorbs and reflects. The light colored sands (high albedo) will make the it reflect much more heat, but at night the heat disperses rapidly, while darker terrain will absorb more and release the stored heat at night. Bodies of water serve as heat reservoir and make the climate around them cooler in summer.

Part of it has to do with wether the location is coastal or inland, and which side of a mountain range it is located on. I think that in summer months costal locations are cooler, but in the winter warmer. I also think that it has to do with currents whcih bring the warm air back down before they reach mountains and stuff.

The air is cooler at the top of the mountain. Forests block out the sunlight, so it's cooler.

it is hotter at lower elevations being cause you are closer to the core of the earth which is more then 1500 degrees celcius and the sun can be klight years away hence this is why you might feel warmer when you are at lower elevations

it is hotter at lower elevations becoz temperature decreases with rise in altitude.there fore at higher elevation it is cooler.

Heat rises to the surface of the earth.

well in deserts it only really hot in the daytime, during night it gets really cold. beaches are only hot when they are close to the equator. and mountains are cold because of altitude

you're thinking apples to oranges...manufactured heat such as fire vs. atmospheric temperatures. Separate the two before trying to figure anything out!