A woman walks through a park in snow-covered Sarajevo. [Reuters]

Even to the local people, snow in Sarajevo, the capital of Bosnia-Herzegovina, in the middle of May must have come as quite a surprise. Early on Monday morning they would have been shocked to pull back their curtains to see a covering of snow across the city, lying to a depth of 9 centimetes.

The wet snow is reported to have weighed heavily on the trees, some of which were responsible for bringing down power lines, leaving some 50 villages in surrounding areas without power.

Only those with long memories could recall such a thing. In fact, the last time snow had settled so spectacularly in the month of May was way back in 1962 and before that, in 1953. May snowfall is usually a very transient feature. When cold weather hit the city in May 2005, the snow melted almost immediately.

What made the snowfall even more surprising, was that it had arrived after a spell of exceptionally warm weather. This began on the 26 April and had brought temperatures as high as 28 degrees, some eight degrees above average.

This rapid swing from ‘hot’ to ‘cold’ is a recurring feature of the region which experiences two different climate types.
In the south of the country, close to the coast, the influence of the warm Adriatic Sea keeps winters mild and summers relatively cool.

Inland areas, including the capital, are hilly, with elevations of up to 2,300 metres.  Here, winters are cold and long. But the prevailing wind direction holds the key.

The warm weather experienced over the previous two weeks was as a result of winds blowing from the south, originating over North Africa.

Monday’s active cold front also brought a change in wind direction. The front dragged cold air from the northwest which could be traced all the way back to the cold Baltic Sea. The undercutting cold air soon turned the rain to snow and brought about a drop in temperature from 27C on Saturday afternoon to just 0.3C early on Monday morning.

Although temperatures have now recovered, another drop in temperatures is expected on Thursday, when temperatures will struggle to reach 6C and there is a chance of further snow.