Day of First Freeze 1948-2015 Philadelphia Int'l Airport

At the start of the month, we talked about the Paris climate change conference and what we're doing to prepare for global warming. Record high temperatures were set over the weekend and more highs are likely this week. But it’s another warm weather-related event that has us concerned: Last Sunday, December 6, was the first time in fall 2015 that the official temperature at Philadelphia International Airport was at or below 32º F.

This is about a month later than the average date of the first freeze, and it's the first time we've gone without a freeze through November. In fact, when looking at the period of record from 1948-2015, it's the latest the first freeze of the year has happened, beating the previous record of November 28, set in 2010, by eight days. And while weather is not climate, the date of the first freeze has been getting later over the last few decades. 

We are in an El Niño year, and it’s true that the weather pattern has brought us warm Decembers before. But much more interesting is the fact that 2015 will be the hottest year ever recorded. Global warming isn’t about a few days where we can break out the shorts in mid-December; it’s about whole the planet getting hotter over time, and we’re watching it happen right now. 

As our climate becomes warmer and potentially more unpredictable, Philadelphia Water recognizes the need to make investments to ensure an abundant supply of clean drinking water and a healthy environment for Philadelphians. That's one of the reasons we're implementing energy improvements at many of our facilities. Examples include solar panels at our Southeast Water Pollution Control Plant and cogeneration—making electricity from gases in sewage—at our Northeast Water Pollution Control Plant.

Those tools will help us bring down energy costs and reduce our carbon emissions, something every utility in every U.S. city should be working towards if we are going to meet the goals established in the historic climate change pact world leaders agreed to in Paris over the weekend.

Not all of our climate change risk adaptation measures are big, engineered systems involving energy production.

We also have a dedicated Climate Change Adaptation Program that's working to identify how our water systems and drinking water sources could be impacted by global warming consequences like rising sea levels. You can read more about that work here.

There is growing evidence that widely distributed green stormwater infrastructure—particularly vegetated systems such as rain gardens, planters and tree trenches—can help cities become more resilient by addressing flooding, mitigating the urban heat island effect, and absorbing carbon dioxide in the air.

Note: Temperature data for Philadelphia International Airport were obtained from NOAA's National Climate Data Center here. The chart above was made with R, ggplot2 and