Great Basin Monthly and Seasonal Fire Potential Briefing: June to September 2026

Added: 2026-06-03

[00:00:01]This is the Great Basin seasonal outlook for June through September.

[00:00:06]Look at what's going on, what goes behind the forecast. One of the things we look at this time of year is fire activity. This was taken in the last week of May and if you're familiar with our fire map off of our website, the new fires are in the the red, exist recent fires are in the yellow, and we had multiple fires. We normally don't see a map like this until we get into the latter part of June, but here we are in late May.

[00:00:31]And these larger red circles, especially these open circles, are large fires of several thousand acres burning in a variety of fuels. A lot of it is in the short to medium grass, but some of it is in higher terrain and in some heavier fuels. So, 1 2 3 4 5 five large fires that we had ongoing.

[00:00:52]PL2 right now is our activity level both here at geographically and nationally.

[00:00:59]Looking back to the month of May, it was temperature-wise above normal month. A lot of areas, I would say overall, most of the areas about maybe 2 to 3 degrees above normal, but there was a strip here in this darker yellow or orange that was 3 to 6 degrees above normal. That's pretty significant, good grass growing weather, too.

[00:01:19]Percent of average precipitation of varying degrees of below normal for the month of May through just about all areas. Now, interestingly, if we go back to April, look at the precipitation, there was a very heavy batch of precipitation. Several inches of rain fell in a fairly short time across southwest Idaho, about 400% of normal, and that set the stage for a possibility of a late season, but good grass crop in southwest Idaho. So, we're watching that developing right now.

[00:01:50]Looking at a longer stretch from October 1st through the end of April, our traditional wet season, you can see how much of the region especially the southern half was about 50 to 70% of normal precipitation.

[00:02:03]It was a very dry winter. Our soil moisture very dry especially you can see these darker red colors. These are the lowest percentiles and the reason we show this sometimes is it does portend to a poor grass crop in the lower elevations. That is one thing.

[00:02:21]And this whitish area here actually suggests that you know there is a possibility for a decent grass crop in parts of Southwest Idaho as well as further up the Snake River Plain. But also when you have dry soil in the Four Corners area that tends to sometimes lead to a quicker formation of the Four Corners high by mid summer which tends to lead to a pretty good monsoon. So this indicator by itself would indicate that perhaps a monsoon a robust one could be coming on time if not even a little sooner than normal. But there are other factors involved. We'll discuss those in a second. An experimental product the Great Basin Rangeland Fire Probability Map. And again the brighter the colors from yellow to red the more fire probability there is from fine fuels and some good carryover fuel. So some concern south of Boise. This doesn't even go into account for some of that grass crop that could be coming out later on this spring into early summer.

[00:03:20]The darker blue colors indicate basically a pretty poor fine fuel crop availability for low elevation fires.

[00:03:30]The US Drought Monitor does show a large developing area of drought in the severe to extreme category across uh the southern two-thirds of the geographic area and even a a portion [clears throat] of exceptional drought popping up in portions of Southwest uh Idaho in the extreme Southwest. Also a little corner here in Northeast Utah. So this uh drought monitor condition will only get worse as you go on time. And the only limitation of the drought monitor for predicting fire activity is sometimes it goes back a little too far, 12 to 18 months worth. Uh whereas lots of times it's that 2 to 4-month period that really sets the stage for us. And our 3-month drought outlook shows the most extreme uh drought conditions on the flash drought monitor being in our southern and eastern areas, but also starting to creep up a little bit towards Idaho.

[00:04:22]A look at our late March, early April snowpack. It's usually the peak snowpack. That's really when it counts, not really the current now, but uh back back then it was really low. Uh 10 to 20% across most of the uh southern 2/3 of our mountainous terrain. Uh up in Idaho is more like 66, 68%, 66% in western Wyoming, but normally anything below 70% is uh pretty alarming for uh an earlier melt off and an earlier start to uh fire conditions in the higher terrain. So, even up in Idaho and Wyoming that's a little disconcerting, but um very bad uh news for a lot lot of our central and southern mountains.

[00:05:03]Looking at ERCs in some areas uh across the central uh uh Snake River Plain where we've had several large fires burning in some of the uh finer fuels. You can see that the uh ERCs [snorts] uh recently, where this blue line is, tickled the 90 uh 90th percentile. Um It then dropped down a little bit, but starting to rise back up to about the 85th percentile. The normal where it should be is this gray line here. So, we're actually near or above the midsummer average peak for that part of Idaho. But, there's still some greenness in the grass there, but it's drying out fast.

[00:05:39]Now, we look at the higher terrain up down over in the Dixie National Forest in far southern Utah. And that shows that the ERCs are progressing towards and just above the 90th percentile.

[00:05:51]That's near normal, actually a little bit above normal for them and that trend is expected to also continue as we go into June. So, what else happens from here is what the weather and the climate is going to do and we have to ask ourselves is there a La Niña or an El Niño, at least a strong one, that could possibly influence the weather a little bit and we've been in a La Niña pattern now for the last two and a half years where we've had cooler conditions and wetter conditions in the north and drier than normal conditions in the south. El Niño, on the flip side, pushes the Pacific storm track, at least part of it, down to the to the south and brings wetness to southern areas of the United States. Usually a warmer and drier regime across the northern Rockies and quite often the Great Basin's caught in the middle of both of these.

[00:06:39]This typically doesn't get come into full effect until uh the wintertime months. However, um when if the El Niño is expected to be very strong and starts getting going by midsummer, um then this southern storm track could bring in some short waves that could flatten out the four corners high that tends to develop, which tends to be the driver of the monsoon. So, that could delay the monsoon despite the the dryness and the soil moisture. So, we're watching both of those things very carefully. Really hard to render a verdict on the monsoon right now. We might just have to go week-to-week on it, but overall, the um computer models that track the El Niño and La Niñas, this is where the sea surface temperatures in the equator are. The projection is the average of all these scatter plots of these models is to have it to be a strong El Niño developing rapidly. So, this is a pretty strong one, above a two, 2.3 or so on average and this could go even higher. So, this suggests that possibly this could disrupt the little bit of the monsoonal flow, could bring isolated scattered showers and thunderstorms from a different direction from the west, but maybe not the deep monsoonal moisture. And this is what El Niño looks like, in case you're wondering.

[00:07:55]It's a anomalously pool of warm water along the equatorial Pacific starting off the South American coast and extending well out into the Pacific and the temperature gradient between this warmer than normal belt of temperatures and the somewhat cooler water north of there accentuates that Pacific storm track into the southern United States and kind of keeps the Pacific Northwest and northern Rockies kind of high and dry. So, this is a projection from one of the models.

[00:08:23]So, our climate outlook for the month of June, a strong signal of above normal temperatures for Pacific Northwest, much of Idaho, I would say about 3/4 of the geographic area, and even the southeast corner somewhat above normal, just about everywhere.

[00:08:40]Equal chances down in Texas. Now, the monthly precipitation, the strongest monsoon signal looks like it stays east of the Great Basin. Doesn't mean it won't windshield wipe back and forth a little bit, but not sure if we'll see a prolonged monsoonal onslaught. Now, this could change again depending on whether the El Niño develops rapidly or whether the dry soil moisture recreates the Four Corners high quickly. Right now, there could be some glancing blows in eastern or southeastern Utah, but by and large, most of the geographic area expectancy of a warmer than normal and near or drier than normal June.

[00:09:19]Now, for July, August, and September, the 3-month average, again, focusing on much above normal temperature probabilities for the entire geographic area.

[00:09:31]Now, this projection is for the monsoon to develop in earnest and overspread the eastern portion of the Great Basin. Uh but this is a 3-month average, July, August, and September. There is a possibility if the monsoon is delayed, July could still be a robust month and then August and September, possibly some wetness in the eastern areas. And there are conflicting opinions on how this axis develops as well as the timing. But we put all the pieces together and for June, we feel that our ticket is punched for just about all areas as we get into the drier part of our summer and uh not typically seeing the monsoon developing yet. So just about all of Utah and eastern Nevada.

[00:10:09][snorts] And even though we have all areas, we we do want to highlight that the valley areas um are not the concern.

[00:10:17]It's the middle to higher elevations where we have denser brush going into PJ and dense timber. Those will be the areas of concern and just about every PSA has some zones like that. So without making the map look too weird, we just highlighted them all. But just keep in mind, this is mostly for middle to higher elevations. Even southeast Utah, we do have the Manti-La Sal Mountains that do get up towards uh uh 12 or 13,000 ft and they um have a good belt of forest below that. So that's something to look at through here. And of course, the Spring Mountains are concern um outside of Vegas.

[00:10:50]Now for July, we do expand our concerns northwards.

[00:10:54]We've already had recent fire activity here in much of southern Idaho. We feel that'll become more consistent by the end of June into July. Also concern for the Sierra. Now we've left the southern part of our area in, but again, timing on the monsoon, this could dissipate a little bit. Uh by August, this is a statistically a normal progression where you do get some monsoon moisture, whether it's a strong monsoon or a moderate or even a weak. You get a couple days of rainy weather and that definitely takes the edge off of fire activity and we think that probably south of the uh I-80 corridor will be that line that um should be um minimal. And this could happen a little sooner or a quicker. We'll try to fine-tune this as we get closer to the time period. But again, the focus goes into all the Idaho mountains, like we said, even though they had higher snowpack than areas further south, having only 65% of your snowpack means you're going to have a pretty robust fire season at some point up in Idaho, unless the weather does something different. And we are expecting the dry punch of weather to definitely be up there. And again, for September, um, tricky, but we feel that again, that trend of warm dry conditions will be accentuated in our northern areas, and that's where we expect fire activity to continue as we go on towards late summer. So, looks like a long, hot, fiery summer for uh, a large portion of our area as we go through the next couple of months.

[00:12:17]That's our outlook, and we publish this on the first of every month.

[00:12:21]Have a good one.