When to Go in Buenos AiresEdit This
The best time to visit the Southern Patagonian region of Argentina is in the summer, while winter is the best season to visit the northern regions, but Buenos Aires is lucky, as it's a good place to visit anytime of the year. The climate stays pretty stable and comfortable all year long, despite having four distinct seasons. There are very few extremely hot or cold days during the year. Remember that because Buenos Aires is located in the Southern Hemisphere, the seasons are the opposite of those in the Northern Hemisphere.
Spring and Autumn
Spring in Buenos Aires begins September 21st and continues through December 21st. The average temperature is around 64 degrees Farenheit and the humidity levels are reasonable. It is very similar to autumn, from March 21st to July 21st. In autumn, the temperature hovers around 66 degrees, and again, has reasonable humidity. Even though Buenos Aires has a good climate the entire year, the best times to visit are probably these two seasons. The most frequent rain showers do occur during autumn and spring, but it doesn't really affect any activities. Just take an umbrella, and it's no problem.
Summer, December 21st to March 21st, makes for a nice visit as well, however, be forwarned that it gets pretty hot, peaking at about 110 degrees. There is also a high percentage of humidity during this time of year, usually in the 80%-90% range, so walking around the city can make you work up quite a sweat. At night the temperature cools down a little, but it still stays warms. Nighttime is the best time for walking, the only problem is that all the day-time attractions like museums and historical buildings will be closed.
From July 21st to Septemper 21st is winter, temperatures stay in the 40s, but with a coat, the weather is great for walking around Buenos Aires. Nothing freezes and there is no snow during winter. The coldest month of all is July.
There are a few variations in the climate pattern that occur almost every year in Buenos Aires. Around June 24th, for about 3 to 7 days, "St. John's Little Summer" occurs. Temperatures can get up to 75 degrees, so it's like a little summer right in the middle of the colder seasons.
The "Santa Rosa Storm" occurs at the end of winter and the beginning of spring. It consists of concentrated heavy rain and thunderstorms.