Climate changes in north west Argentina

As with the rest of the world,  the climate in North West Argentina is a little less predictable than just a few years ago. It used to be that Salteneans would predict noticeable change from the date of each equinox, for example September 21st  the first day of spring,  heralded warmer weather and the likelihood of rain within the month, while on March 21st the first day of autumn invariably a cooler wind blew and the nights become chilly when the sun went down.  

They were absolutely right and with uncanny precision to which you could set the date!

The Salta area is particularly famous for possessing an agreeable year-round climate. If there was an ideal time to come then it would be in spring and the beginning of summer but each season brings its own speacial charme.

We are now well into Autumn, the rainy season is petering out, but everywhere is still lush and green and the mountains are softened by their leaves . In the early autumn it’s a wonderful time to visit the high valleys where maize, peppers and chillies are harvested and left in the sun to dry. The days are hot but as soon as the sun goes down you need a jumper or fleece.

The wine region begins to bring in the grapes at the end of February but the process frequently continues into April when the vines are clipped back to their winter state. The high altitude and low humidity of the main wine producing regions in the Calchaqui valleys, mean that these  vineyards rarely face the problems of insects, fungi, molds and other grape diseases that affect vineyards in other countries. This allows cultivating with little or no pesticides, enabling even organic wines to be easily produced.

The dry winter climate changes the character of the region as most trees are deciduous and most other plants unless they are watered regularly go into their winter hibernation. This gives the terrain a harder personality as fields become brown  and the trees are bare. The area has  extremely dry and cool winters with regular frosts (a mean of 10 °C in Salta and 10.5 °C in Jujuy in July). However as daytime temperatures can rise to 24 + the diurnal range in these cities is fairly large. The large thermal amplitude is caused by intense radiation from the sun, causing the land to heat up by day, while during the night, there is less radiation, causing the land to cool and temperatures to fall down.

Roads are one the greatest casualties as surfaces expand and shrink rapidly leaving broken surfaces.

This is a great time for touring as the daytime temperatures are comfortable and most hostelries have blazing fires to keep you warm at night. Indulge in the amazing array of woollen goods for sale in the artisanal markets.

Early September can bring snow, but by the third week temperatures are rising and the days are getting longer, and the world starts to become alive again. Daytime temperatures fluctuate between 23°C and 30°C, with lows rarely falling below 10°C. A feature is the warm Zonda wind which comes up from the south via the foothills of the Andes. It lasts a day or two and can reach gusts of 70 kms per hour.

Showers start late October. The spring is very rarely humid and the warm fresh atmosphere plus the rain enable a profusion of flowers to bloom. No wonder this is called Salta la Linda.

By November it is very warm most days with an average of 30 d depending on the altitude. The atmospheric layer is very thin here so the UV rays are powerful and extra sun protection care is needed.

At the height of summer temperatures can hit the 104°F (40°C) mark and flash thunderstorms occur.  Outdoor living really comes into its own, the markets and street stalls are bursting with fruit and roadside BBQs offer tempting al fresco foods. Shade is always at a premium and you learn quickly never to go out without a sunhat.

Cool winds crossing the warm plains from the Atlantic hit the eastern Andes and rise to form convection clouds which produce thunderstorms. Classically the storms build up over 2 or 3 warm sunny days to shed their loads during the early evening. The thunderstorms when they come are short but heavy and often cause local flooding but the air after the event is fresh and the atmosphere is cleared of dust.