Northern Rockies Weather
North Idaho NW Montana Forecast Discussion Weather Stories Resources Donate About
Weather Stories

What Effect does El Niño or La Niña have on weather in North Idaho and Northwest Montana?

Edit

Update the details and content for this story.

What Effect does El Nino or La Nina have on weather in North Idaho and Northwest Montana?

    There has been much discussion around our region about the upcoming winter season and this is a regular occurrence at this time of year in the Northern Rockies. Add to that the media hype surrounding the so called and erroneous label of a “Super El Nino” that has developed across the tropical Pacific Ocean and all kinds of strange and hyped up possibilities have been given. This brief article will hopefully supply some answers to the many questions I have been receiving from a variety of people in our region as well as hopefully clear up some of the myths and mysteries surrounding El Nino and La Nina.

What is El Nino and La Nina? The terms El Nino and La Nina are actually short translations for what is known in meteorology as El Nino Southern Oscillation or ENSO for short. El Nino is the warm phase of this phenomenon while La Nina is the cool phase. Typically in the tropical regions of the world upper level winds as well as surface winds blow from east to west due to the coriolis effect of the earth’s rotation. Surface high pressure areas develop around 30 degrees north and south of the equator with the corresponding circulation around these features causing the trade winds to blow from east to west and​​ thereby pushing warm water in the Pacific Ocean west towards the Philippines and Japan. During El Nino years the trade winds weaken and actually reverse which pushes a lot the warm water in the West Pacific into the Central and East Pacific. During La Nina years the trade winds are typically stronger in the Pacific Ocean with colder waters upwelling from beneath to replace the movement of warmer surface waters into the West Pacific. The location of the warmer waters can have profound and large scale implications to the jet stream in both the Northern and Southern Hemispheres.

What is the current state of the 2026/2027 El Nino? The current state of the still developing El Nino as of this writing in early October 2026 is one that is classified as a very strong El Nino with ocean temperatures in 3 of the 4 “Nino regions” running more than 2 degrees celsius warmer than average. There is no such thing as a “Super El Nino” and that term is nothing more than media hype.

What has the historical effect of El Nino or La Nina been on the weather of the Northern Rockies? It is widely reported and believed across much of the media that El Nino winters mean warmer and drier winters for the Northern Rockies while La Nina winters mean colder and snowier winters. Those statements are factually untrue according to the CO-OP data for our climate stations at the Western Regional Climate Center. Having looked back at data for the climate sites that have good records in our region (Bonners Ferry, Priest River, Sandpoint, Libby and Eureka) the numbers are not as concise. There is a better correlation of the mild and dry winters with El Nino and cold, wet winters of La Nina for the Pacific Northwest with that focus really more on the region of Washington and Oregon from the Cascade Mountains west. Across our region this is simply not the case. In fact looking back at the top ten heaviest snowfall winters in recorded history at the climate sites listed above 4 of those winters were El Nino years, 3 were La Nina years and 3 were neutral years meaning neither El Nino or La Nina.

Addressing the concerns of the general public regarding the upcoming winter and the Very Strong El Nino’s effect on North Idaho and Northwest Montana: Many people especially in the winter sports businesses are concerned about another winter with a lack of snowfall because of El Nino. As stated above, this is statistically not the case for our region as past climatic data from previous years does not show a strong correlation one way or the other based solely on the ENSO state. It is honestly a toss up as to what our winter will look like. It could be a heavy one with a lot of snow, it could be a dry one, it could be one with a lot of rain. Does the Very Strong El Nino mean we will see worsening drought? Again that is a toss up and anything is entirely possible. One of the main problems we have in not having good predictions on what will happen is that our records for ENSO years only date back to 1950 so there is not a long enough period of time to make an accurate prediction with how this winter will play out. On the flip side there is a stronger correlation with El Nino years in our summer weather pattern up in the Northern Rockies with years dominated by El Nino during the previous winter, spring and summer often resulting in wetter conditions during the summer months of June, July and August. In addition there are many, many other factors that have not been studied that play important roles in our weather patterns which are listed in the next section. Much of what is being circulated on social media platforms and the media in general is n​othing more than sensationalism. The final factor is that we have very few Very Strong El Nino years in recorded history and this one is certainly shaping up to be one of the strongest if not the strongest in recorded history but likely not the strongest ever.

What other factors determine weather patterns in the Northern Rockies? There are several factors that play into the weather patterns of the Northern Rockies and actually across the entire Northern Hemisphere. They are complex and not much research has been done on their correlation to date. One of the more significant contributors to our local weather is the Madden Julian Oscillation (MJO for short). Others include the Ouasi-biennial Oscillation (QBO), the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO), the Pacifiic Decadal Oscillation (PDO), the Indian Ocean Dipole (IOD), the Pacific North American pattern (PNA) and lastly sun spot activity. All of these factors along with the more common El Nino and La Nina conditions have effects on weather patterns in the Northern Rockies as well as the rest of the world. How each of these interact with one another as well as the cause and effect are still being studied and understood. 

What does the 2026/2027 Winter Outlook look like for the Northern Rockies? Given the complex situations listed above, I am not going to make a prediction on the upcoming winter for our region. I will state that I am more inclined to believe the Old Farmer’s Almanac’s winter forecast and there summer 2027 forecast for our region. If the reader desires to know more specifics then feel free to pick up a copy as this forecaster did. The Old Farmer’s Almanac’s forecasters look at several factors and from my experience for our region they are correct more often than not. For example the Old Farmer’s Almanac had predicted a mild and very wet winter for 2025/2026 for the Northern Rockies with very little snow and that is exactly what happened. Just about every other prediction was calling for a very cold and snowy winter for the Northern Rockies but these were based almost entirely on the El Nino/La Nina argument. The Old Farmer’s Almanac also called for a very dry and warm but not very hot summer across the region for 2026. This was also completely correct. It was a warm summer but not exceptional and not one of the hotter summers either. The summer months (June, July and August) all ended up at just about average for temperatures. It was however an exceptionally dry summer and one of the driest in recorded history, also accurately predicted by the Old Farmer’s Almanac. In a nutshell, the brief prediction from the Old Farmer’s Almanac for our region is calling for a mild but snowy winter. If that prediction does in fact come true, that will make this forecaster a very happy camper. The bottom line is that the upcoming winter really has no clear signal for our region one way or the other but again this forecaster is going with the Old Farmer’s Almanac prediction.

How can we prepare for the upcoming winter? For locals that have lived in the Northern Rockies for a long time winter preparation is often the same each year as anything is possible. For those of you who have moved to the region over the last 10 years or so read the section on the Northern Rockies Weather Website on the “Climate of North Idaho and Northwest Montana”. This will give you a good idea of what all four seasons of our region contain. The direct link to the climate section of the website can be found here: 

https://northernrockiesweather.com/weather-stories/story/6b2d11b3-19d5-4c65-93dd-7d0c5dd824af/

I hope this article is helpful and useful and helps to quiet some of the sensationalism that is circulating around.