Can you explain your variables a little more? For example, is temperature the average temperature for the year in the country? This kind of explanation for the rest will help make sure you definitely need to investigate autocorrelation (although it sounds like it's possible).

It's also probably possible to just use 5 dummy variables for the 6 countries (so one MLR), but it'll depend on issues that pop up if you need a different or new kind of model.

Did your software report an approximate p-value on the DW statistic?