Why is the summer temperature high in Tarim Basin or Pearl River Delta?

The temperature in Tarim basin in summer is higher than that in Pearl River Delta.

The height of the sun in Tarim at noon may be smaller than that in the Pearl River Delta, but the daytime is longer, and the solar radiation intensity is not significantly different from that in the Pearl River Delta. The climate in Tarim basin is dry and sunny, and the atmospheric radiation to the sun is less weakened, and the solar radiation reaching the ground is more and the temperature is higher. The Pearl River Delta region is rainy in summer, and the solar radiation from the clouds is much weakened, and the solar radiation reaching the ground is less and the temperature is lower.