Hacienda Heights experiences mild winters, with temperatures ranging from freezing to moderate highs. Spring brings a gradual warming trend, with average highs increasing by up to 10°C by May. Summer months are warm to hot, with temperatures often reaching above 40°C in July and August. Autumn sees temperatures cool again, but not as sharply as in winter, with average highs still in the mid-to-upper 20s by October. Winters can be chilly, especially in December, but rarely drop below freezing for an extended period.