Those 90-degree days’ time has likely passed

It’s still slightly more than two weeks from Sept. 23, the official start of fall. Many folks have said how much they enjoyed the summer and really don’t want it to end, but there are some who say they’re ready for the cooler weather.

September is the third-driest month of the year with an average of 0.78 inches of precipitation at the Spokane International Airport. In Coeur d’Alene, the normal amount of rain is 1.58 inches. Last year, less than half the amount of normal precipitation fell, with only 0.32 inches gauged in Spokane and 0.74 inches at Coeur d’Alene.

The rest of September still looks drier and warmer than normal, but there should be more moisture than in September 2006.

I also believe we’ve seen the last of the 90-degree temperatures for this season. From June through early September 2007, there were 22 days at the airport with temperature readings of 90 degrees or higher. Coeur d’Alene saw 31 days at or above 90 degrees. There were also two days in Spokane with highs above the 100-degree mark. Most of the hot weather came in July, one of the hottest Julys in recorded history. The mean temperature was 7 degrees above normal at 75.6 degrees.

Despite the warmer- than-normal temperature prediction for September, it’s possible there will be very chilly or frosty weather toward the end of the month. Once this predicted cold spell ends, temperatures should quickly rebound, giving the Inland Northwest much warmer conditions around the first week in October.

If ocean waters in the south-central Pacific Ocean remain cooler than normal, the storm door in our region should open by no later than mid-October. The normal precipitation for October at the Spokane airport is 1.06 inches. The normal for Coeur d’Alene is 1.93 inches. Moisture totals should be above normal, especially toward the end of October.

Snow is not common in October, but elevations above 5,000 feet may see some measurable snowfall. The most snow ever measured in October at Spokane and Coeur d’Alene happened on Oct. 22, 1957, when 5.9 inches fell at the Spokane airport while Coeur d’Alene measured 6.8 inches. With the increased precipitation, October temperatures should be slightly cooler than normal.

November should also see above-normal amounts of precipitation. In November 2006, the Spokane International Airport logged an impressive 4.38 inches of moisture. According to Idaho Climatologist Cliff Harris, Coeur d’Alene received 7.63 inches with a record 26 out of 30 days receiving at least 0.01 inches of precipitation last November.

Although I expect to see more precipitation this November, conditions shouldn’t be quite as wet as last year. For 2007, much of the region should see approximately 20 percent to 30 percent higher-than-normal moisture totals. Up to half of our November precipitation may fall during the middle of the month. Normal rain and melted snow for Spokane is 2.24 inches with an average of 2.97 inches in Coeur d’Alene in November.

Speaking of snow, Spokane normally receives about 5 inches in November while Coeur d’Alene sees slightly less than 8 inches. Snowfall should be near normal in Spokane with slightly above average totals expected in the Spokane Valley, Coeur d’Alene and in the higher mountains. Temperatures are expected to be slightly below normal in November as well.