SEATTLE -- Did you know that statistically the Fourth of July has had the most frequent occurrence of rain of any other day in July?

Over the past 116 years, it's rained 33 times on the Fourth. But this year will not be 34. In fact, it 's continuing a surprising stretch of nice Fourths -- last year it was 71 but in 2007, it was 84, which had been the warmest Fourth in quite some time.

This year seeks to break it.

A moderately strong heat wave is in progress that will cook the interior of Western Washington Friday and Saturday before a little relief comes Sunday, and then we fall off the table Monday.

A thermal trough, which normally brings a hot, east wind is building into the area, but it's not a particularly strong one forecast models show it forming farther east into Eastern Washington.

It's close enough to bring a warm air mass, but we haven't really had much of an east wind -- more like not much wind at all to perhaps a very slight northwest wind. Also while we have a very warm air mass in place, it's not in the extreme category. Bottom line is while it'll be hot by our standards, we are not looking at record heat.

Highs Friday are expected to generally reach the mid-upper 80s although the record high is just 90 degrees set in 1972 so that's probably not impossible, just unlikely.

If that's too warm, the coast offers some escape. Since the east wind isn't roaring, the coast is relatively mild with highs now only expected in the 70s.

Fourth of July Saturday is now looking like just about a carbon copy of Friday -- quasi-hot inland, cooler along the coast. Highs around the Puget Sound area will be in the mid-upper 80s, with 90s south and east of Seattle, but 70s on the coast.

It should make for spectacular weather conditions at fireworks time, with temperatures still in the 70s/low 80s but those near Puget Sound -- and I'd count in Gas Works Park on this -- you still might want a light jacket as there could be a light seabreeze.

But while it's great viewing weather, this hot and dry stretch has made for extremely dangerous fire conditions. A Red Flag Warning, indicating such risk, is in effect for all of Western Washington until midnight Monday morning.

Fire officials ask for extreme caution when using fireworks or campground fires. Small sparks can easily create big fires that rapidly spread.

It looks like we'll get some cooling for Sunday in the form of a better seabreeze in the afternoon, but still a warm day with highs in the upper 70s/low 80s.

The big push of marine air is scheduled for Sunday night, and that will lead to a considerably cooler Monday with clouds around most of the day and highs only in the mid-upper 60s. We stay generally mostly cloudy and cool with occasional mountain showers through the middle of next week.