Kennewick's winters are cold, with temperatures often dropping below freezing and averaging around 4°C in January, but still occasionally rising above 20°C. Spring arrives slowly, with March temperatures ranging from -6°C to 24°C, gradually warming up through April and May, which see highs of 31°C and 33°C respectively. Summer is hot, with July being the warmest month, averaging 27°C, while August and June are close behind, but also experience occasional heatwaves reaching as high as 47°C. Autumn brings a return to milder temperatures, with September averaging around 18°C and October cooling down to an average of 12°C. Winter returns, with December and January again seeing temperatures frequently below freezing.