On Twitter, a reader notes that black homicides tend to be more seasonal than white homicides:
This more or less checks out: blacks died by homicide according to the CDC death certificate database about 22% more in June to August over the years 1999-2020 than in December to February.
For whites, the seasonal gap was only 7%; for Hispanics 18%.
The gap between July-September versus January-March is 27% for blacks, 16% for whites, and 23% for Hispanics.
But all September figures are inflated by 9/11 in 2001.
For whites, about 20% of all homicide victims in September over that 22 year span died in the terrorist attacks on 9/11.
|Sep (includes 9/11)||16812||12086||6222|
|Jul vs. Jan||23%||6%||19%|
|Aug vs. Feb||43%||17%||34%|
|Sep vs. Mar: 9/11||17%||25%||17%|
|Oct vs. Apr||7%||7%||12%|
|Nov vs. May||-8%||-2%||0%|
|Dec vs. Jun||-5%||2%||-5%|
|Jun-Aug vs. Dec-Feb||22%||7%||18%|
|Jul-Sep vs. Jan-Mar||27%||16%||23%|
My impression from local news coverage is that a lot of blacks get murdered at outdoor parties or on the sidewalks outside clubs, so the current temperature matters more.