RAIN, RAIN DOES GO AWAY ON THIS DAY.

Byline: Greg Bolt The Register-Guard

If you're ever at the track and spot a horse named "Dry Fourth of July," bet the limit.

Odds are, that horse is going to win, at least if the race is the Western Oregon Weather Derby.

Today will be a winner, too. At the very least it will not rain, just as it has not rained on the Fourth of July in 57 of the last 68 years (not counting four years with a trace of rain, which meteorologists say don't count as "wet" days).

It might not seem that way to some, particularly to Eugene residents of a certain age. Hang out with some of the old-timers at today's Butte to Butte run, for example, and you're likely to hear something like, "This is nice. It usually rains on the Fourth of July."

No, it does not.

But pardon those seasoned road warriors if they remember things a bit differently. For a time, you see, it might have seemed like the sky had it in for the Butte to Butte.

Launched informally in 1973, the first races happened to coincide with an unusually damp run of early July weather. In the first 10 years the race was run, at least a trace of rain fell six times on July 4. You'd think someone named Abby Normal was running the race.

And then there was the memorable 1992 race, on a Fourth when just shy of an inch of rain sluiced down city streets. That has to stick in a lot of memories.

Toss in the unknown number of years when it rained the day before or day after the Fourth, or both, and the holiday's local reputation makes a little more sense.

Oregon State University climatologist George Taylor, director of the Oregon Climate Center, said it's not surprising that some people have a poor opinion of Fourth of July weather in the Northwest. It's a day when many people are trying to have some fun in the sun, and getting rained out tends to stick in the memory, even if it's a rare occurrence.

"Our own perceptions and our memories are quite flawed; I don't trust my own," he said. "The human memory in these situations is not trustworthy."

But let us not be too hard on those who do not remember the Fourth of July well. In fact, there is a statistical anomaly that feeds into that.

According to the data, the July day most likely to see rain is July 3, followed closely by July 4. Since 1939 it has rained 17.9 percent of the time on July 3; on July 4, 16.4 percent of the time.

Still, July is the epitome of summer. It is the driest month of the year, both in Eugene and statewide; it is in a virtual dead heat with August as the hottest month.

And today should live up to July's temperature reputation. There's a chance the mercury will top 90 degrees, which would be the first time that's happened since 1997.

The record of 95, last seen in 1972, is safe.

And one last bit of Independence Day weather trivia to ponder over a cold beverage: The Eugene temperature has equaled or exceeded 90 degrees six times on the Fourth of July since 1939; it has failed to top 70 eight times.

29.9

Probability of rain on June 28,

expressed as a percentage

16.4

Probability of rain on July 4,

expressed as a percentage