Welcome to Fire Season 2025

Welcome to the Washington Smoke Blog and to wildfire season 2025! This post will cover the ongoing Canadian fires, a seasonal outlook, and a preview of "smoke-ready week" next week (June 9-13). 

Canadian Smoke

Fires (shown as orange dots/thermal anomalies), clouds, and smoke across Canada and the Northern U.S. on June 6, 2025. Data from NASA Worldview.

Canada is off to a fast and furious start to their fire season, particularly in the central provinces of Alberta, Manitoba, and Saskatchewan. Activity in far northern British Columbia is also picking up. Smoke from these Canadian fires has been drifting into portions of the central and eastern U.S. at times over the last few weeks, deteriorating air quality and making news headlines. While the size and severity of these fires is above normal, the timing is typical for that region. In most years, some fires typically establish across the boreal forests of central and eastern Canada in late Spring and early Summer (May-June). This is the period after snow melts but before the vegetation ‘greens up’ in the early summer months. Smoke from Canadian fires thus far has remained east of Washington state and our air quality remains good. This is typical - Washington generally does not experience ground-level smoke impacts from fires that occur east of the Rocky Mountains. 

We CAN experience smoke from Canada when fires establish closer to home in the mountains across southern British Columbia, but the timing of that would be more in line with our typical peak of fire season (July to September). Activity in that area is minimal right now but we’ll be monitoring closely for new activity as we head deeper into summer.

A Dry Spring

A key trend in Washington heading into fire season is our lack of late spring precipitation. This has been true across most of the state but is particularly notable across the dry forest environments along the eastern slopes of the Cascades and Blue Mountains. On average these are some of our most active regions for wildfire and this year they are heading into fire season having gone without significant rainfall for months.

Precipitation anomaly (% of normal) over the last 60 days - from April 6 to June 4, 2025. Much of the Pacific Northwest has seen precipitation amounts only 25-75% of the 1991-2020 normal. Data via climatetoolbox.org.

Here is another way to look at recent precipitation trends, using percentiles. Areas in dark brown have seen their lowest precipitation amounts in the April 6 to June 4 period since the dataset began in 1979! Data via climatetoolbox.org.

In spring and early summer, vegetation typically goes through a period of growth and then subsequent curing and drying. Without much recent precipitation, the curing and drying process is already well underway across the lower-middle elevations of central and eastern Washington. Grasses and shrubs are ready to burn in many areas. In fact, recent weeks have already featured a handful of early season fires in lower elevations of eastern Washington and Oregon. As heat builds further into the weekend, conditions are rapidly becoming favorable for additional fire activity in those areas – especially when combined with incoming strong winds Monday through Wednesday next week. 

Probability of the hot-dry-windy index exceeding the 95th percentile, valid next Tuesday, June 10. Data via https://hdwindex.fs2c.usda.gov/index.html.

Cooler temperatures and lighter winds should arrive by the end of next week to ease concerns for significant fire growth. Additionally, even with the lower than normal precipitation trends, the higher elevations and much of western Washington are still limited in their fire growth potential by live, green vegetation. That will change as we head later into the summer and things dry out further.

Forecast Summer Conditions & Lightning Ignition Potential

After the initial period of potentially critical fire weather early next week across central and eastern Washington, what will the rest of summer look like?

The NOAA Climate Prediction Center has much of the U.S. West favored for above normal temperatures this summer, including the Pacific Northwest. Hot temperatures combined with low relative humidity can rapidly pull moisture out of vegetation, increasing the potential for that vegetation to burn. There are certainly other factors - wind, vegetation type, short-term weather patterns, topography, and fire suppression capability, to name a few. And of course, we still need ignitions to have fire. But unusually warm summer temperatures will generally stack the odds in favor of larger and more difficult to manage fires. For example, July 2024 was extremely hot across the region and played a major role in readying the vegetation across Oregon for what ended up being a record fire season in their state.

We can also look at the seasonal precipitation outlook which is suggesting below average rainfall across the Pacific Northwest for the rest of the summer. Keep in mind that summers are typically dry in our region to begin with, so the precipitation outlook is a minor factor relative to the temperature outlook. 

One of the main uncertainties for this season is how the southwest monsoon will evolve. On occasion, moisture from the southwest monsoon can work its way northwards, creating enough moisture and instability in the upper part of the atmosphere to trigger thunderstorms - but not enough actual rainfall reaching the ground to provide benefit. These dry lightning episodes can ignite many new fires all at once across the landscape, often in difficult places for firefighters to access. At this point we don’t have good insight into the potential for dry lightning over the summer. But it’s something we are watching closely and could rapidly change the outcome of the season, especially given the background warmth and dryness that's expected.  

Putting it Together: Significant Wildland Fire Potential

With the dry spring and likely warm summer, the odds favor above normal fire activity across the entirety of the Pacific Northwest. This is reflected in the official forecasts produced by the National Interagency Fire Center. These forecasts paint the picture for above normal large fire activity starting in June across eastern Washington and Oregon before expanding across the rest of the Pacific Northwest in July and August – potentially even continuing through September.

Many Smoke Unknowns - And The Importance of Readiness

Though a very active fire season is likely, it's never a guarantee. Additionally, even if we have large fires on the landscape there is an entire other set of questions we need to analyze about smoke:

• Are fires becoming established in forests or lighter fuels such as grass and shrubland? It's the forest fires that create much more smoke and for longer periods of time.
• How far away are fires around the region to Washington communities?
• Where is the wind blowing the smoke? Towards or away from where people live?
• Is the smoke located at ground level, where people breathe, or simply moving overhead higher up in the atmosphere?

The smoke blog exists in part to help you answer these questions throughout the season and stay up to date on the latest information. 

While the local air quality is still good, now is a great time to prepare yourself for smoke! In fact, next week (June 9-13) is officially "smoke-ready week", and we’ll be kicking it off with additional blog posts starting on Monday! Stay tuned ...