Record Highs, Temperatures 10-15 Degrees Above Normal to Begin October

FastCast—Saturday, Oct. 1 to Saturday, Oct. 8:

October will begin with record high temperatures that are 10-15 degrees above normal. Highs will reach 75º+ degrees for most of the first week of October in the lowlands. Highs on Saturday, Sunday, and Monday will potentially reach 80º+, which is quite rare for October. Sunday and Monday’s highs will likely challenge daily records. By Tuesday, a few more clouds will return, with conditions remaining partly cloudy to mostly sunny through next Saturday (Oct. 8th). Highs from Tuesday to next Saturday will be in the mid to upper 70s. Lows throughout the entire week will be in the low to mid 50s, except in the upper 40s in outlying locations. Most days will have a northerly breeze that will keep highs near Puget Sound in the low to mid 70s. In Eastern Washington and other traditionally warmer locations, October will begin with over a week of highs in the upper 70s to mid 80s. On the plus side, morning lows will be crisp, in the upper 40s to low 50s. We will have to watch for any degraded air quality due to the lingering smoke from the Bolt Creek Fire as flow is generally offshore. AQI may degrade due to near-surface smoke on Saturday.

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Continue reading the full blog below!

It will be an abnormally warm beginning of October, with many days above 75º expected. The European model forecast for temperature anomalies in the Pacific Northwest on Monday afternoon says it all.

Notice that highs in Western Washington will be 10-20 degrees above average on Monday. This trend of highs anywhere 5-15 degrees above average will be consistent through at least the first 8 days of October. 

Before we examine the upcoming high temperatures, the HRRR forecast for near-surface smoke on Saturday afternoon/evening is below.

This near-surface smoke is from the Bolt Creek and White River Fires in the Stevens Pass vicinity. Some will also come from lingering fires in the North Cascades. Expect air quality to degrade to the moderate category, with isolated locations reaching the unhealthy for sensitive groups category. This is possible on Sunday as well, but the HRRR model hasn’t done too well with these smoke forecasts in the past couple weeks. A good place to monitor hyperlocal air quality is the PurpleAir AQI map. It is updated frequently with AQI monitors all around the region, maybe even in your neighborhood!

Let’s take a look at the highs for this weekend. It will feel like late summer! The HRRR forecast for Saturday is below.

Expect lowland highs in the mid to upper 70s, except in the low 70s near the water. Areas near the Cascades may reach the low 80s due to downslope flow. Also, notice the downslope flow bringing significant warming to Abbotsford, BC and parts of Whatcom County. Highs up to the mid 80s are possible. Offshore flow will bring highs in the upper 60s to low 70s to the Washington Coast. Areas from Olympia south and in Eastern Washington will reach the low 80s on Saturday.

The HRRR forecast for Sunday is reminiscent of late August.

Sunday will be quite warm. Expect lowland highs in the upper 70s to low 80s. Areas near Puget Sound may only reach the mid 70s. Areas near the Cascades, downstream of the Fraser River valley, from Olympia south, and in Eastern Washington have a chance to hit the mid to upper 80s. Offshore flow will bring highs in the upper 60s to upper 70s (warmest inland).

Monday is expected to be as warm or slightly warmer than Sunday. High temperature records are possible on Sunday and Monday. Stay tuned for updates on Monday’s temperatures and the extended period of highs in the mid to upper 70s.

A good way to see the expected trend in temperatures is in the NWS Climate Prediction Center outlook. The graphic below shows the likelihood of above or below average temperatures for October 6-10 (Thursday to next Monday).

Wow…a huge area of an 80-90% chance of above average temperatures (darkest color). Most of Western Washington has a 70-80% chance of above average temperatures heading into the second week of October. 

Additionally, the much drier than normal September has prompted the US Drought Monitor to place almost all of Washington state in the “abnormally dry” category. 

This map, released on Thursday, shows about 92% of Washington state in the abnormally dry category, with large areas of Eastern Washington under “moderate drought.” Although this is not good, the huge snowpack and wet spring have kept Washington from being in worse drought. 

Stay tuned to the blog as record high temperatures are possible again on Monday, with warm weather expected for the next week or more.