Costa Rica's Caribbean side has been taking a lashing by rainstorms, forcing 1,688 people into shelters after flooding swamped their homes in the cantons of Matina and Talamanca, emergency authorities reported yesterday.

A low pressure system is pushing the water levels up to dangerous levels in most of the rivers in the area, particularly in the northern reaches of Costa Rica's Caribbean coast, according to a CNE press release.

CNE has issued a red alert – an evacuation call, the highest weather warning level – for Talamanca, in the south, and Matina, to the north.

The central cantons of Limón city, Siquirres, Guácimo, Pococí and Sarapiquí de Heredia are all under yellow alert, the second highest warning, telling residents to prepare for evacuation if the situation worsens.

The Red Cross said relief workers are tending to more than 30 shelters set up across the region, and have been taking small boats and four-wheel drive Unimog trucks to aid residents who were isolated by the floods.

The Central Valley, where San José lies, was on the low-level green alert (take caution) as of last night after weekend rains, according to CNE.

Today the valley could see drier and warmer hours during the day but could return to long rains by late afternoon, according to meteorologist Evelyn Quirós.

Quirós said this weather is not uncommon considering this is the tropical cyclone season, which will continue until Nov. 30.