Coolest July in Sacramento Since 2011 and 2012

It's been such a mild and pleasant July in Sacramento this year, but I was surprised to learn that temperatures are exactly average. That suggested that temperatures must have been above average in recent years. So, I looked at the data. 

Data from two sites are presented: the "Downtown" station (which is no longer downtown, with data available since 1877) and the Sacramento Executive Airport station (with data available since 1947). In general, the Exec Airport site is cooler than the Downtown site (further from the urban center; closer to the Sacramento River Delta). 

July 2025 seems to be the coolest July since 2011 and 2012. 

The increase in July average temperature since 1877 is due to heat island effect as the area urbanized, as well as global warming. The Downtown station has moved several times since its inception, and that might account for some of the variation.