Freezes after a warm September?

We’re coming into the time of year when local gardeners will have to start monitoring the weather more closely, as our region will eventually be heading toward freezing temperatures. It’s almost hard to believe that we’re talking about readings dropping into the low 30s when last month was one of the warmest Septembers in recorded history.

September started off very hot, with the first three days having highs at or above the 100-degree mark. The hottest day was 102 degrees Sept. 2. In fact, that was the hottest afternoon of the entire summer season. Although we did have some mild afternoons last month with four days in the 60s, the average high for September of 2025 was 82 degrees. The normal high for last month in Coeur d’Alene is 74 degrees.

At the Spokane International Airport, the hottest afternoons were Sept. 1 and 2 with a high of 99 degrees. The airport averaged nearly 8 degrees above normal last month and only reported 0.43 inches of rainfall.

Many locations will likely have freezing temperatures Monday morning. If the mercury doesn’t hit the 32-degree mark in Spokane and Coeur d’Alene, the next best chance for freezing temperatures in Coeur d’Alene is around the new moon lunar phase that begins Oct. 21.

Since 1895, the average date for the first freeze in Coeur d’Alene is Oct. 16. Since 2000, the average date for Coeur d’Alene’s first freeze has been Oct. 14. The coldest reading ever recorded for October occurred Oct. 31, 1935, with a low of 2 degrees. More recently, the chilliest temperature was 13 degrees Halloween, Oct. 31, 2006. It was 20 degrees Oct. 10, 2009. Two days later, in the same year Oct. 12, the mercury dipped to a frigid 15 degrees. That was one of the worst early October cold waves to hit the region in history.

On the flip side, one of the latest freezes occurred in the Coeur d’Alene region in 2014. The mercury didn’t drop below 32 degrees until Nov. 10, with a low of 27 degrees. In 2021, we had our first 32-degree temperature of the fall season occur Oct. 7, but in 2022, we didn’t have temperatures at or below the freezing mark until Nov. 3, when the mercury dipped to 30 degrees. Last year, readings first dipped below the freezing mark Oct. 18, but did come close much earlier with a low of 34 degrees Sept. 30.

The earliest freeze in Coeur d’Alene since 1895 happened Aug. 25, 1910, with a low of 32 degrees. In Kellogg, it was a cold morning in 1969 when the morning low dipped to 31 degrees Aug. 9. In Spokane, Sept. 10, 1895, was the earliest 32-degree temperature after the summer season.

In terms of moisture, only 0.09 inches of rain was measured at Cliff’s station, which was the seventh month in a row with below normal precipitation. That figure is not the lowest moisture total for September. There were about a dozen months since 1895 with no measurable rainfall in September. The most recent September with no moisture occurred back in 2008. However, some locations, especially in the rural areas, did pick up more substantial amounts of rainfall in late September. At this time of year, we often get a “hit or miss” rainfall pattern.

As I mentioned in an earlier article, we’re still challenging the 1929 seasonal moisture total of 15.18, the lowest annual precipitation in Coeur d’Alene’s history. During that year, from Jan. 1 through Sept. 30, there was a total of 9.93 inches. For 2025, the seasonal moisture total from Jan. 1 through the end of September was 8.62 inches. In Spokane, the seasonal rainfall total through September was 7.48 inches.

As of early October, there is still a good chance that conditions will start reversing toward the wetter side, especially in the coming months. The long-range forecast models indicate a series of storms that are expected to bring some much-needed rainfall to the region later this month, especially around the new moon phase of Oct. 21.

With an expected cooler La Niña, many forecasters are pointing to an increase in rain and snow in the coming months across the Pacific Northwest. Cliff and I are expecting the moisture totals to increase with a predicted seasonal total of just over 21 inches of rain and melted snow in Coeur d’Alene. It’s below the average of 26.77 inches, but not the driest year in history. However, we seem to be stuck in this pattern of wide weather extremes. Since the early 2000s, our region has been experiencing many wetter-than-normal years. This year could be a flip to the drier side. It’s too soon to tell, but we’ll have to wait and see.

In the meantime, this new La Niña is expected to be relatively weak and brief. New forecast models are indicating that sea-surface temperatures are expected to return to “neutral,” or as we call it, a “La Nada” in early 2026. Stay tuned.

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Contact Randy Mann at [email protected].