Winters in Arvada are cold and variable, with temperatures often dropping below freezing and staying that way for extended periods. January and February are typically the coldest months, with average temperatures ranging from -4°C to -6°C. Spring arrives slowly in March, with temperatures gradually warming up towards 0°C, but can still drop to -24°C on occasion. Summer brings warm temperatures, with July being the warmest month, averaging around 18°C, although it's not uncommon for highs to reach up to 40°C. As autumn sets in, temperatures cool down again, returning to averages closer to 0°C by November.