Summers in Cologne are warm, though rarely to the point of uncomfortable heat, positioning the season right in the middle of the busiest May-to-September tourist season. The warmest months are July and August, both of which have a daily average high temperature of 23.7 degrees Celsius, or about 75 degrees Fahrenheit. June is marginally cooler, and the evening lows for the whole summer on average are around 11 degrees Celsius, or about 52 degrees Fahrenheit. Summer days also can be rather humid. The summer months are Cologne's wettest, although rain spells generally are short-lived and often occur overnight. June and July both see about 86 millimeters, or about 3.4 inches, of rain.
Cologne cools off quickly in the fall, with temperatures beginning to near the freezing point by the time November rolls around. September remains pleasant, with an average high of 19.6 degrees Celsius, or about 67 degrees Fahrenheit, and an average low of 9.6 degrees Celsius, or about 49 degrees Fahrenheit. Later in the fall, in November, that low has dropped to 2.5 degrees Celsius, or about 37 degrees Fahrenheit, and the high has hit 9 degrees Celsius, or about 48 degrees Fahrenheit. Rainfall totals are the highest in September, an average of 69.3 millimeters or about 2.7 inches, and the rainfall amounts taper off a bit in October and November.
While Cologne can get a little chilly in the winter, snow is rare and usually doesn't stay on the ground for long, and the city's temperatures are among the warmest in Germany. Skies are often overcast in the winter, however. February, on average, is the coldest month, with an average daily low of -0.9 degrees Celsius, or about 30 degrees Fahrenheit, but the average low hovers around the freezing mark for all three months. High temperatures for the three months are around 6 degrees Celsius, or about 43 degrees Fahrenheit. February also is the driest month of the year, with a total average rainfall of 46.6 millimeters, or about 1.8 inches.
Cologne warms up steadily in the spring. March still starts out a little chilly, with an average daily low of 1.7 degrees Celsius or about 35 degrees Fahrenheit and an average daily high of 10.5 degrees Celsius, or about 51 degrees Fahrenheit. By May, the climate has warmed to an average daily high of 19 degrees Celsius, or about 66 degrees Fahrenheit, though the evenings remain cool. The weather also begins to get a little wetter in May, with an average total rainfall of 72.4 millimeters, or about 2.9 inches. Both March and April have slightly lower total rainfall amounts.
Outside of the occasional thunderstorm, Cologne is not particularly prone to bouts of severe weather. The city has seen a few extreme temperatures over the years, however. The hottest temperature ever recorded occurred in August, when it reached 36.1 degrees Celsius, or about 97 degrees Fahrenheit. January saw the coldest day, when the temperature dropped to -23.3 degrees Celsius, or about -10 degrees Fahrenheit. Winds also have gotten as high as almost 89 kilometers per hour, or 55 miles per hour, in December.
