Philadelphia - Hottest Decades





Ranked here are the hottest decades on record for Philadelphia, Pennsylvania. The lists include decades when Philadelphia had the highest average temperatures, the most hot days and the fewest cold days. These extremes are for temperatures observed at Philadelphia International Airport and cover seven decades, from the 1950s to the 2010s.

That is when Philadelphia had weather measurements that are consistent and complete enough to compare decades. Each decade comprises a standard 10-year range. For instance, the 1990s includes measurements from Jan 1, 1990 to Dec 31, 1999. An exception is the 2010s which so far includes data to the end of 2018. Links to the data behind these lists are in the References section on this page.

Hottest High Temperatures

Average daily maximum temperature at Philadelphia
High °F Decade High °C
Highest 65.8 2010s 18.8
Runner-up 65.2 1990s 18.4

Warmest Low Temperatures

Average daily minimum temperature at Philadelphia
Low °F Decade Low °C
Highest 48.9 2010s 9.4
Runner-up 47.6 2000s, 1990s 8.7

Most Warm Days

Total days per year on average when Philadelphia had temperatures of at least 70 °F (21 °C)
Days Decade
Highest 172 2010s
Runner-up 164 2000s

Most Hot Days

Total days per year on average when Philadelphia had temperatures of at least 90 °F (32 °C)
Days Decade
Highest 34 2010s
Runner-up 31 1990s

Fewest Freezing Days

Total days per year on average when Philadelphia had temperatures of 32 °F (0 °C) or lower
Days Decade
Lowest 76 2010s
Runner-up 77 1990s

How Much Hotter are 2010s?

Compared with averages for the previous 50 years (1960 to 2009), the 2010s in Philadelphia had:

  • 10 more days each year with temperatures of 90 °F and higher
  • 1.9 °F higher daily maximum temperatures (1.0 °C)
  • 2.9 °F higher daily minimum temperatures (1.6 °C)
  • 15 fewer days a year with freezing temperatures
References

Current Results. 2019. Philadelphia PA Temperature Averages by Decade

Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Year, Version 1.0. NOAA National Centers for Environmental Information.

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