Walnut Creek experiences mild winters, with temperatures ranging from near-freezing to moderate highs. January and February are the chilliest months, but even then, temperatures rarely drop below 0°C. Spring brings warming temperatures, with April and May averaging around 14°C to 17°C. Summer is warm, with July and August often reaching highs of 41°C, while September cools down slightly. Autumn sees a return to milder temperatures, similar to those in spring, before winter sets in once more.