WEATHER & CLIMATE
The area where San Carlos de Bariloche is located enjoys a temperate mountain-type climate, although it belongs to the continental cold weather zone with a dry season.
December 21 is the longest day in the year. The sun rises around 5:30 a.m. and sets at 9:30 p.m. However, in mid-winter, it rises at 8.30 a.m. and sets at 6.30 p.m. approximately.
In this area temperatures tend to be quite variable, independently of the season of the year. Something to be borne in mind is the temperature variance between night and day. At this latitude, the difference between maximum and minimum temperatures tends to be quite wide. So you should be aware that temperature forecasting in Patagonia tends to be very difficult.
On the Mt Catedral ski center, temperatures are always lower than in the city because of the higher altitude. The wind is another factor influencing the "thermal sensation" or sensation of temperature as we ascend.
Lake waters are always cold, fluctuating between 12 and 15 ºCelsius. The deeper the lake, the harder it is for the sun to heat the water up. Some small lakes get frozen over during very cold winters, just like the lakes we can find on high mountain territory.
RAINFALL IN BARILOCHE
Precipitation occurs the whole year round in Bariloche, especially in the May-August period, which totals over 150 mm whereas the rest of the year accounts for less than 50 mm. Median rainfall is 1.6 mm, and the lowest is after February.
An important change in rainfall occurs as we go from west to east. The rainfall gradient goes from 4,000 mm annually in the Cordillera area, such as Puerto Blest, to only 600 mm a year in the Limay River area.
Fro example, on the steppes that are east of Bariloche, there is always good weather, and it only rains 300 mm a year. However, if you travel westwards towards the Chilean border, you will find it rains much more. In the Lake Frías area, near Puerto Blest and on the Chilean border, it rains 3,500 mm. a year.
These climatic variances, plus the differences in soil and relief, produce significant changes from region to region in the flora and fauna.
The dominant winds are from the west and are usually strong, especially in springtime. October and November are usually very windy months, with gusts that sometimes are higher than 100 kilometers an hour, although this rarely happens.
However, it is a fact that permanent winds are usually found over the whole area to a greater or lesser extent. One very rarely gets an absolutely calm day, even in summer.
An effect to bear in mind is the influence of the wind on the sensation of temperature: the strong gusts play havoc with the readings from thermometers.
WEATHER IN NAHUEL HUAPI NATIONAL PARK
The weather in the Park is temperate to cold with clear differences between the seasons. The summers are dry, with average temperature ranging from 14 to 16° Celsius, and maximums of 30°C in January. Winters are humid and it snows often. July temperatures average 2 to 4°C and minimum temperature averages -15°C.
THE SEASONS in Bariloche
An important fact is that the weather does not vary strictly in accordance with the calendar seasons, and sometimes one has low temperatures and rainy weather in summer as well.
Winter in Bariloche ... snow and skiing
Winter days may be cold and snowy, or bright and sunny. Daylight extends from 9 a.m. to 7 p.m. Temperatures average between 2 and -10° Celsius. Snowfall in San Carlos de Bariloche city can vary from 10 up to 50 centimeters in the harshest winters.
Spring in Bariloche ... flowers and fishing
This is the time that days get longer and temperature begins to rise slowly. At the same time, the rainfall starts to diminish very gradually.
The nights are cold. During the daytime, temperatures vary between 7 and 20° Celsius. Towards the end of the season, during the months of October and November, strong west winds appear, with gusts during the night that can be of over 100 km/hr.
Summer in Bariloche ... the lake and the mountains
This is the season of warm, sunny days and cool nights, little rainfall and dominant southwest winds. Due to the low latitude of the city, daylight extends from 6 a.m. up to around 10 p.m. Temperatures con reach 32° Celsius during the day, dropping to 18° C at night. Occasionally the temperature drops very steeply and the peaks of the mounts appear powdered with snow in the morning.
Fall in Bariloche ... a riot of color
The days are cool to temperate, and the nights are cold. Average temperatures vary between 4° and 13° Celsius. This is the season of cold, luminous and dry days, although now and then there are intense rains, and some early snowstorms, especially on the mountaintops.