# Correlation between weather condition and event

I have car accidents data and related weather information. To keep it simple data looks like that:

accident_datetime  |  accident_zip  |  weather_condition (sun|rain|fog|snow)


I want to visualize correlation between number of accidents and weather condition. I would go with average number, let's say when it snows there are twice more accidents then when it sunny, but in this case I will need weather condition data that is not linked to accident. Do I have any options?

Thanks.