Climate variables values are given per region rather than per post code e.g the whole of region 1 sheep farms (North) with 200 farmers responding to questionnaire the temperature value = 15, region 2(south) temperature=16.

The values for the outcome (number of cases/sick sheep) has been given per farm/post code.

My main problem is the small margin of variation between independent variables seem too be too small making it harder to model them with the outcome or come up with best method of analysis.

Is the statistical method I could employ to help work out the association between climate variables and number of disease cases given such small margins when it comes to independent variables.

Any advise will be much appreciated and thanks in advance