100 degrees: Near record for number of years in a row?

From 2002 through 2009, the temperature in Philadelphia never hit 100.

This week, it's possible the city could reach the triple-digit mark for the fourth straight year.

Sounds like more evidence of global warming?

Maybe, maybe not.

A four-year streak already happened, back in the 1950s, with highs of 100 in 1952, 101 in 1953, 102 in 1954 and 100 in 1955, according to meteorologist Anthony Gigi of the National Weather Service's Mount Holly office.

And three-year streaks happened from 1993 to 1995 and 1917 to 1919.

That streak from nearly a century ago included the hottest day on record in Philadelphia -- 106 set on Aug. 7, 1918.

The next two hottest days hit 104, on July 10, 1936, and July 3, 1966.

103 has been hit seven times, including 2010 (July 7, after hitting 102) and 2011 (July 22, with 101 the following day).

Last year hit 101 on July 7 and 100 on July 18.

Tying the four-year streak record is possible, Gigi said.

Temperatures are forecast in the upper 90s for the next five days, with 97 anticipated Wednesday.

See "Brutal heat wave to hit Philly this week."

If the sun can burn off some of this "pretty ugly" humidity and dry things out, conditions might, unfortunately, favor even hotter highs, Gigi said.

But even if the 100-streak hits four straight years, that's not predictive about next year -- or even next month, Gigi said.

The last three sweltering Julys were followed by less-steamy Augusts, and after the 1993-95 streak, 1996 saw a high for the year of 94, he pointed out.

See "Highest temperatures of the last 25 years."

Contact staff writer Peter Mucha at 215-854-4342 or pmucha@phillynews.com.