In April, Thornton typically sees daytime highs of 17.2°C and overnight lows around 0.9°C. Compared to the annual average high of 18.6°C, April runs -1.4°C.
April in Thornton averages a daytime high of 17.2°C and an overnight low of 0.9°C.
April runs -1.4°C compared to Thornton's annual average high of 18.6°C, ranking #7 of 12 months by warmth.
Plan for daytime highs near 17.2°C and cooler evenings around 0.9°C.