Temporal & Seasonal Aspects of Crime

There are three types of crimes for which police incident reports are likely to reflect the actual number of offenses. They are homicides, auto thefts, and burglaries. It’s hard to re-classify a homicide as something else, and auto thefts along with burglaries generally get reported, as a police report is needed for insurance reasons. One of the things that is important to note when looking at property crimes such as burglaries is that the time of the incident represents the time when the offense was discovered, rather than when it actually occurred e.g., a burglary that has an incident time of 17:35, means that this is when the incident was discovered and reported to law enforcement, and that the actual event could have happened any time between the time the home owner left, and when they returned to their home, such as 5:35 pm etc.

This means when looking at the times of day when a burglary may have been committed it is better to analyze periods of the day e.g., when looking at offenses that took place during weekdays (in Boston), it can be seen that 53% occur sometime between 8 AM and 6 PM (when people are at work), 22% between 6 PM and 11 PM, and another 25% between midnight and 7 AM. It’s also interesting to note that 73% of all burglaries – again, in Boston - are reported on weekdays rather than on the weekend. This could suggest a couple of things concerning burglary e.g., that burglars avoid breaking into houses over the weekend because they know people are likely to be home, and/or that the weekends are a time when those who commit offenses spend time with family, friends etc., just like those who are engaged in legitimate employment. It is also interesting to note that there is little seasonal variation where burglary on weekends is concerned except for the winter months of December, January, and February, that account for only 20% of burglaries, with the other seasons accounting for 80% of offenses, divided almost equally. This is probably due to more people staying home over the weekend when the weather is cold and not as pleasant. This isn’t replicated for weekdays, where there is little seasonal variation concerning burglaries i.e., on a weekday people don’t have a choice about staying in or going out - to work - when the weather is bad.

With occupancy, and the signs of occupancy, known to be one of the most significant deterrents for burglary, work routines, and inclement weather are going to be a factor in whether people stay home or go out.  Whilst burglaries in LA, almost follow the same pattern on a day-by-day, hour-by-hour basis compared to Boston and Philadelphia, they don’t follow the same seasonal/monthly pattern e.g., if you live in LA your house is almost as likely to get broken into in July as it is in December etc., something that is not the case in either Boston or Philadelphia. Winter in LA rarely sees temperatures dropping below the mid-60’s, so people are less likely to be staying indoors during those months compared to those who live in the Northeast, and are likely to hunker down at home when temperatures drop. Also, offenders may be put off by bad weather e.g., who wants to go out and commit a break-in when it’s snowing and below freezing? It’s much easier and more comfortable to stay indoors than go out looking for a restricted number of offending opportunities. When we look at crime, whether it’s a street robbery or a burglary, weather plays its part. In Summer too when there are heatwaves, more offenses are committed later at night, when temperatures cool down a bit.

Street robberies have also been shown to be affected by the weather. A 2015 study by Bowers and Tompson, on the West Coast of Scotland, showed that the number of these offenses dropped when it was raining but only during the weekend, when travel was optional. In bad weather there was a reduced number of potential interactions between motivated offenders and suitable targets, leading to a reduction in crime. However, there may be a “cultural” aspect to the way that weather affects offending patterns e.g., as a locale gets used to seasonal weather patterns those living there may adapt, and learn to manage their routine activities, in line with the weather; people who live in wintry climates have learnt to live with snow and ice, and so don’t necessarily stay at home when the weather turns inclement, whereas a cold patch/spell in Florida or Texas is more likely to catch people by surprise and unprepared, and so their response may be to change their routines and the amount of time they spend at home avoiding going out into public spaces etc.       

Research has shown that Journeys to Crime, concerning burglaries, are also affected by both weather and the time of day, with offenders making shorter journeys both later at night, as well as when the weather is bad etc. Offenders are as affected by the climate and the time of day as non-offenders e.g., someone needing to get groceries late at night and/or if it is snowing etc., is more likely to go somewhere closer than farther away. When we start to think of “crime” as a routine activity, that is similar in this way to legal pursuits, we get a better understanding and idea of how offenses are committed and weather, along with time of days affects such activities for all of us.