In September, Grand Junction typically sees daytime highs of 27.5°C and overnight lows around 10.5°C. Compared to the annual average high of 18.9°C, September runs +8.6°C.
September in Grand Junction averages a daytime high of 27.5°C and an overnight low of 10.5°C.
September runs +8.6°C compared to Grand Junction's annual average high of 18.9°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 27.5°C and cooler evenings around 10.5°C.