Meursault in The Stranger seems to spend a lot of time describing the temperature, and especially the heat. There are numerous cases where he mentions the sun and the heat:
It occurred to me that all I had to do was turn around and that would be the end of it. But the whole beach, throbbing in the sun, was pressing on my back. I took a few steps toward the spring. The Arab didn't move. Besides, he was still pretty far away. Maybe it was the shadows on his face, but it looked like he was laughing. I waited. The sun was starting to burn my cheeks, and I could feel drops of sweat gathering in my eyebrows. The sun was the same as it had been the day I'd buried Maman, and like then, my forehead especially was hurting me, all the veins in it throbbing under the skin. It was this burning, which I couldn't stand anymore, that made me move forward. I knew that it was stupid, that I wouldn't get the sun off me by stepping forward.
[...]
At the same instant the sweat in my eyebrows dripped down over my eyelids all at once and covered them with a warm, thick film. My eyes were blinded behind the curtain of tears and salt. All I could feel were the cymbals of sunlight crashing on my forehead and, indistinctly, the dazzling spear flying up from the knife in front of me. The scorching blade slashed at my eyelashes and stabbed at my stinging eyes. That's when everything began to reel. The sea carried up a thick, fiery breath. It seemed to me as if the sky split open from one end to the other to rain down fire. My whole being tensed and I squeezed my hand around the revolver. The trigger gave; I felt the smooth underside of the butt; and there, in that noise, sharp and deafening at the same time, is where it all started. I shook off the sweat and sun.
The Stranger, part 1: chapter 6
Again without any apparent logic, the magistrate then asked if I had fired all five shots at once. I thought for a minute and explained that at first I had fired a single shot and then, a few seconds later, the other four. Then he said,
"Why did you pause between the first and second shot?"
Once again I could see the red sand and feel the burning of the sun on my forehead.
The Stranger, part 2: chapter 1
But I can honestly say that the time from summer to summer went very quickly. And I knew as soon as the weather turned hot that something new was in store for me. My case was set down for the last session of the Court of Assizes, and that session was due to end some time in June. The trial opened with the sun glaring outside.
[...]
A short time later a small bell rang in the room. Then they took my handcuffs off. They opened the door and led me into the dock. The room was packed. Despite the blinds, the sun filtered through in places and the air was already stifling.
The Stranger, part 2: chapter 3
What is Meursault's obsessions with the heat all about? Why is it so consistently mentioned and brought up?