Oshkosh experiences cold winters, with January and February averaging around -5°C and -9°C respectively, while occasional temperatures as low as -27°C are not uncommon. As spring approaches, temperatures gradually warm up, with March averaging around 3°C and April seeing highs of up to 27°C. Summer months bring more consistent warmth, with June through August all averaging around 21°C, but still experiencing some cooler days. Autumn is similar to spring in terms of temperature fluctuations, with September averaging 17°C and October returning to averages around 13°C. Winters return with temperatures dropping below -20°C again by December.