# Decades of 100s, but just how many days?

HOUSTON – I love my viewers and data, so this recent email was sent to the right person:

“You may have sent this recently, but has anyone put together a chart showing the number of 100+ degree days each decade since 1960?”

-- Joe

That’s an interesting question and a pretty easy one to answer actually, but there are different ways to look at the answers! I used June to September maximum temperature data from Hobby Airport for the 1960s and Bush/IAH for the rest of the decades. Speaking of which, let’s first break this down by decades:

1960s: Five summers (1962, 63, 64, 65, 69)

1970s: Five summers (1970, 71, 76, 77, 78)

1980s: Five summers (1980, 85, 86, 87, 88)

1990s: Six summers (1990, 93, 94, 95, 98, 99)

2000s: 10 summers, all of them

2010s: Nine summers, all but 2014

2020s: Three summers out of four so far

You could surmise from this that climate change is basically doubling the number of 100° summers from five to six each decade to nine to 10. But that would be misleading in a sense and remember Joe’s question was how many days each decade have hit 100°, not just getting to that temperature each summer. For that answer, pull up a chair.

In the 1960s, 1962 had nine days of 100+ while 1963 had one, 1964 had three, 1965 had one and 1969 had four for a total of 18 days.

In the 1970s, 1970 had one day, 1971 had one day, 1976 had one day, 1977 had one day and 1978 had six days for a total of just 10.

In the 1980s, 1980 had 32 days of 100+, 1985 had one, 1986 had eight, 1987 had two and 1988 had four for a total of 47 days!!

So while each of those decades had five summers of triple digits the number of 100° days differed significantly! Let’s keep going: