Exploring the influence of thermal discomfort due to muggy weather conditions on violent crimes and aggressive behavior in Catalonia (Spain) in the period 2010-2019.
Authors: Mazon Jordi , Valdés Irene , Castellà Judit 
Published: July 2023

The relationship between weather and some meteorological parameters with human behavior, and even, crime has been well-established by several studies (e.g. Anderson et al., 1995; Cohn, 1990; Mazon, 2013; Potgieter et al., 2022). The thermal disconfort due to high values of both temperature and water vapor in the atmosphere in summer and early autumn in the Mediterranean areas, mainly in the coast, leads to a persistent feeling of muggy weather conditions day and night, which might affect human behavior. Based on this hypothesis, an investigation has been performed to explore the relationship between the heat index and four different typologies of crime from the Catalan Regional Police daily database 2010 to 2019.&#160;&#160;
In the first stage of the research, violent crimes in Catalonia during the period 2010-2019 has been analysed, with the aim of finding whether periods with a high rate of crimes are mainlyin summer, and with a lower rate in winter. Various types of crimes of aggressive nature were examined, and those that positively responded to the hypothesis proceeded to the second stage. An analysis of the summer periods of those typologies of crimes that passed the first stage were analysed in the second part, in which arelationship between days with higher crime and days with a higher heat index (muggy weather) was explored.
The results suggest that a relationship does exist between violent crimes and muggy weather conditions as three of the four typologies of violent crimes vary with weather seasons: crimes increase when summer arrives and there is a drop in winter in criminal offenses such as bodily harm, tortures, and against sexual freedom.
Nevertheless, in the second stage of the research, results are not that clear. Crimes of torture give confusing results which leads to the conclusion that these do not hold a relationship with the heat index. However, the other two typologies show that there is a higher probability of a correspondence between peak days of crimes and days with a higher muggy weather level. Therefore, there seems to be a relationship between violent crimes and muggy weather conditions, specifically in the typologies of crimes that involve bodily harm and crimes against sexual freedom and indemnity.
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References:
Anderson CA, Deuser WE, DeNeve KM, 1995. Hot temperatures, hostile affect, hostile cognition, and arousal: tests of a general model of affective aggression. Personal Soc Psychol Bull 21(5):434&#8211;448.
Cohn EG, 1990. Weather and crime. Brit J Crim 30(1):51&#8211;64. DOI: https://doi.org/10.1093/oxfordjournals.bjc.a047980
Potgieter A, Fabris-Rotelli IN, Breetzke G. et al., 2022. The association between weather and crime in a township setting in South Africa. Int J Biometeorol 66, 865&#8211;874. https://doi.org/10.1007/s00484-022-02242-0
Mazon J., 2013. The influence of thermal discomfort on the attention index of teenagers: An experimental evaluation. Int J Biometeorol 58(5). https://doi.org/10.1007/s00484-013-0652-0
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