On a rainy day, Angelenos are on average involved in 250% more accidents than on a clear day
And accidents are more likely to occur at almost every single hour of the day.
Between 7-8 am, there are FOUR times as many crashes as when the weather is clear
11am to 12pm there are almost SIX times as many crashes as when it is clear
The only time when it’s safer during the rain: The evening rush hour
From 6pm to 7 pm there are actually one fifth more accidents when it’s clear than when it is raining
How we did it
Los Angeles County is a big place (4,751 square miles). It can be raining in one part and sunny in another. In trying to figure out if accidents are more likely to occur in the rain, we wanted to be able to find exact comparisons.
So, we divided the county into 236 different grids, each measuring approximately 4 miles x 4 miles. We looked at weather data for each grid during each hour of 2016. Then, we separated our results into two categories: clear and rainy.
Obviously, there were more clear hours than rainy ones. So, we took the clear data, and, for each grid, calculated the average number of accidents that occur in a given hour, say, from 8-9 am. We did the same for the rainy hours. This way, we compared each grid at each hour of the day during clear weather against each grid at each hour day during rainy weather.
Still have questions? Send us an email at firstname.lastname@example.org