From the Cliff Mass Weather Blog
Cliff Mass
On July 15/16, a massive lightning storm initiated several major wildfires east of the Cascade crest.
As shown below, this was one of the most extreme lightning events in Northwest history.
This story has escaped the notice of the media. Furthermore, several media outlets (including KING-5 news and the NY Times) and podcasters/Youtube channels have claimed that Northwest lightning has increased over time due to climate change. (see example below)
Actual lightning data show that such claims are demonstrably false.
The data is clear: the major wildfires that occurred during the past month have little to do with climate change, but were associated with a very unusual “lightning storm” of extraordinary intensity.
As I will demonstrate below, there is no upward trend in Northwest lightning, which indicates that global warming is not a major driver of regional lightning frequency.
The Data
There are two major lightning networks that cover our region and beyond: the UW World Wide Lightning Location Network (WWLLN) and the Vaisala National Lightning Detection Network (NLDN).
I first asked UW Professor Robert Holzworth and Scientist Katrina Virts, who run the WWLLN network.
I was amazed to learn that WWLLN detected 5,440 strokes over the PNW on July 16, 2026–the most of any July day in the period of record (since 2013, after which the observing network was stable).
Lightning Strikes on July 15-17.
No wonder there were a lot of fire starts!
Many are concerned about global warming, so I asked the WWLLN folks to see a plot of lightning over time. Katrina made a plot of the number of lightning days per month over the Pacific Northwest (below):
The lightning numbers are DECLINING. And this is a period of substantial global warming. Global warming is NOT contributing to more lightning over our region!.
To get an independent check on these lightning numbers, UW Research Meteorologist Jeff Baars used a completely different lightning network (NLDN), which goes back until the late 1980s.
For this network, July 16 was the third greatest July lightning day since 2013. And examining a far longer period, we see that there is no increasing trend in regional lightning…in fact, a modest decline.
So what should you take away from all this?
(1) The July 2026 lightning event was unusually extreme in terms of the number of lightning strikes, greatly increasing the number of fires.
(2) There is no observational evidence that global warming/climate change is contributing to more lightning strikes (and thus wildfires) over the region.
The latter observational result suggests that some modeling studies, which suggested the opposite, are in error. Clearly, they possess some flaws in their methodology or approach.
