Does It ALWAYS Rain in Portland on the Fourth of July?

4 July 2011 · 3 comments

It seems that over the past few years, it’s become fashionable for Portlanders to complain that it always rains on the fourth of July. In fact, this whining has become something of an epidemic. Nobody wants to make plans outside for Independence Day because of the possibility of rain.

But is it true? Does it really always rain in Portland on the fourth of July? I’m a life-long resident of the area, and I have to say: My memory tells me that Independence Day is usually hot and sunny.

Because I’m tired of arguing about the weather, I dug into the data from the National Weather Service to prove my case. I looked at temperature records and precipitation records.

Here’s climate data for July 4th going back 25 years. What conclusions can you draw from this?


YEAR: HI/LO (RAIN)
1969: 73/54 (.02)
1970: 88/60 (---)
1971: 70/54 (---)
1972: 97/57 (---)
1973: 81/59 (---)
1974: 76/57 (.06)
1975: 92/53 (---)
1976: 76/59 (.03)
1977: 63/48 (.01)
1978: 65/55 (---)
1979: 75/61 (---)
1980: 66/56 (.05)
1981: 88/61 (---)
1982: 69/54 (.02)
1983: 82/50 (---)
1984: 86/60 (---)
1985: 87/63 (---)
1986: 69/52 (.16)
1987: 69/57 (.02)
1988: 69/51 (---)
1989: 74/52 (---)
1990: 83/59 (.07)
1991: 80/55 (---)
1992: 68/60 (.16)
1993: 73/55 (---)
1994: 67/51 (-T-)
1995: 82/61 (---)
1996: 72/54 (---)
1997: 94/61 (---)
1998: 66/57 (.21)
1999: 67/53 (.14)
2000: 65/54 (-T-)
2001: 84/56 (---)
2002: 70/56 (---)
2003: 80/54 (---)
2004: 77/55 (---)
2005: 84/57 (---)
2006: 77/57 (---)
2007: 90/60 (---)
2008: 72/61 (.01)
2009: 92/59 (---)
2010: 67/53 (---)

As you can see, it doesn’t always rain on Independence Day. In fact, over the past 42 years, it’s only rained fifteen times — and only four times with real conviction. What’s more, over the past twelve years (including today), Portland has only received one one-hundredth of an inch of rain on July 4th.

I’ll admit, however, that I’m wrong when I say the fourth is always hot and sunny. It’s not. There are indeed cool days now and then. But the mean high temperature in Portland on July 4th is 77 degrees Fahrenheit and the mean low is 56. The mean rainfall is two one-hundredths of an inch (though the mode is zero rainfall).

So, there you go: It doesn’t always rain in Portland on the fourth of July. In fact, rain is uncommon, and real rain is rare. The next time somebody complains about rain on Independence Day, you can point them to this page! Somehow, though, I don’t think it’ll change their mind.

{ 3 comments… read them below or add one }

1 Dena Shunra 4 July 2011 at 12:48

Thanks so much for this analysis! I’ve been looking for a house to buy in Portland for the past half year, and wondering (for a while) if the weather would be too much for me.
(I currently live in the Olympic Peninsula, which means I have rain-shadow to protect me from rain.)

Your analysis is mighty helpful!

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2 Claudia Gates 5 July 2011 at 13:06

We didn’t have rain in San Bernardino on the 4th of July, but we had 104 degree temperatures! But elsewhere in our large county, there were heavy rains, and flash flood warnings. We drove from our air conditioned house to Jenefer’s un- air conditioned house, but it is nearer the ocean and therefore cooler. Bob bar-be-cued outside, but even with the fans blowing and the windows and doors opened, it was quite warm at times. Happy 4th of July.

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3 Kevin M 6 July 2011 at 10:10

Wow, those temps look great to me. It is usually about 90+ with high humidity in July here in St. Louis.

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