The seasons in Perú

The seasons in Perú

This is a short section which gives you the basic facts about the weather in Perú. You should bear in mind two basic facts about the country.

Overall, the peak season is from June to the end of September. However, recall that Perú is in the Southern hemisphere, and that this is winter. The coast may be cold and humid. However, the highlands are then dry and clear.

In Summer - which starts in November and runs through to April - the coast becomes warm and clear(er), whilst the highlands get rain. This makes travel in the mountains difficult. The period after the rains is particularly attractive in the Andes, but the same months are gray and cold on the coast.

The coastal climate is always dry and usually cool, but it has periods of intense humidity. These tend to peak in Autumn, around March-April. Lima has a climate with is odd even for the coast. The Limeñan Summer is marked by la garúa, a clammy mist that comes off the cold sea and settles on the coast. (Nearby high areas (lomos) have plant life that depends entirely on condensation from this. It never rains on the central coast. The Lachay national park is a little visited area just North of Lima, in which these plants and animal communities thrive.) The ocean gets colder as one goes South (although the marine life increases sharply) and the reverse happens to the North. The Humboldt current pulls away near the Ecuador border, changing the climate and the wildlife of the region.

The jungle is always hot and damp: recall that Perú is only a few degrees off the Equator, and that its coastal climate is dominated by the Antarctic Humboldt current. The Andes block this from the jungle, however, which reverts to the "standard" humid tropics. The midland and Southern jungle are quite seasonal, however, with the hottest period coinciding with the most intense rains, in November-April. The Northern jungle follows this pattern, but is generally hotter, wetter and less seasonal than the South.

The mountain climate varies from North to South, becoming cooler, drier and more seasonal as one moves away from the Equator. The rains run from November to April, and these can make the Andes very difficult. Minor roads can be permanently impassable, and landslips will cut major roads very regularly. Flights are much disrupted. Winter is dry and clear, although cold. The Autumn period - late April to June - allow you to see the highlands undertaking farming activities, which have largely ceased in the drier months.

Hand-ploughing. The yellow is Oxalis, a mountain weed.

The peasant farmers of the mountains evolved a farming calendar which is still used. The new year begins on December 21st, the longest day of Summer in the Southern Hemisphere. However, farm work was thought of as beginning in July, with land preparation and sowing. Potatoes were planted in the months that followed, varying sowing with altitude so as to manage the onset of potato blight during the period of high humidity. September was the month in which irrigated vegetables and chiles were harvested and preserved. October was the month for wood gathering, carpentry and rope making. November and December were the Sun's month, and labour tended to be minimised. The New Moon in January marked the start of major crop tending - weeding, keeping animals off the now-large crops - and this was and is seen as a critical time during which religious protection needed to be evoked.

The next month was the wettest, and irrigation canals were traditionally tended during it. Corn was particularly vulnerable, and people lived in the fields to keep off animals and birds. Informal relationships tended to flourish in the privacy of the dark. The corn harvest arrived in May, to much celebration. Potatoes were reaped in June, and the cycle closed. Those visiting the sierra in March-April will encounter the run up to and celebration of Christian Easter, which has become conflated with these harvest festivals. It can be a dramatic time.

el niño

Perú and Ecuador are the primary countries on the el Niño phenomenon impact, although its consequences are often global. As discussed elsewhere, the coastal climate of Perú dominated by the extremely cold Humboldt current. However, parcels of hot water from the equatorial Pacific sometimes break through this in Summer, leading to heavy rains in the Andes, floods around rivers on the coast and strong winds. The converse of this, la Niña, delivers cold, dry conditions.

Please see below for an explanation

The figure may be over-technical for a guide of this sort. However, it beautifully describes the wobbly, erratic nature of this system. Years run across the bottom of the figure. The colours show the way in which temperature of sea shifts from its average level: red is hotter, blue is colder.

Think of the figure as showing the globe tipped on its side, so that East is "up" and West is "down". The Perúvian coast is, therefore, off the top of the figure, East of California. Waves of hot and cold water march in from the ocean South of Hawaii - that is, up the figure - and smash into the South American mainland.

A blue Niña occurs in 1998, a red Niño in 1992. There are then spasms of movement with no obvious pattern to them. This ultimately built up to the massive event in 1999, which - amongst other things - contributed to the fall of the Perúvian government in that year. It also rendered several thousand people homeless and killed over a hundred.

Despite this underlying complexity, however, a major program of research now allows for fairly good prediction over a six month period, so it is well worth checking out the web site of the US NOAA (National Oceanic and Atmospheric Administration). This offers regular updates on the subject.