Montana Snowpack: Percent of Normal by Station

Q: How many snow stations does Montana have?

96 active stations, of which 87 carry a 1991 to 2020 normal for a given calendar day and can therefore be given a percent of normal at all. They sit across 26 counties and 10 river basins, at elevations from 4,250 to 9,200 feet with a middle around 6,830. The highest is Carrot Basin at 9,200 feet. Every figure on this page states which of those two counts it was computed from.

Today, from the agency file

Where Montana snowpack stands

Reading Montana stations from the agency files…

Every instrument in the state

Montana snow stations on the map

Reading the station map from the agency files…

Station by station

The Montana stations, lowest first

A station is one clearing. It reads the snow lying on its own pillow, and that can differ sharply from a slope a mile away and a thousand feet higher. Reading one station against its own past is far more informative than reading two stations against each other, which is why the last column gives each one its own percentile rather than a rank against its neighbours.

Reading station readings from the agency files…

A snow telemetry station in a forest clearing with a tall instrument mast, a steel precipitation gauge and a fenced snow pillow, surrounded by conifers under snow — One station, which is what every row in the table below is. A clearing, a mast, a precipitation gauge and a fenced pillow on the ground. The clearing matters: put the same instrument under a canopy and the trees intercept a large share of the snow before it ever lands. “Cloud Peak SNOTEL site in Montana” — USDA Natural Resources Conservation Service — Public Domain

By river basin

Which Montana basins are carrying the water

Montana’s stations sit thousands of feet lower than Colorado’s, because the same climate arrives at a lower elevation this far north. A pack at 6,800 feet in Montana and one at 10,300 feet in Colorado can hold the same water, and the Montana one is far more exposed to a February thaw.

The basin names below are the six digit hydrologic units the station records carry, named from the United States Geological Survey boundary dataset. Montana covers 10 of them across 26 counties. A basin appears once three or more of its stations are reporting.

Against its own record

This day, across the Montana record

A single percentage tells you where today sits against a thirty year median. It does not tell you whether that is unusual, and the two questions have genuinely different answers: a state can be at 70 percent of median in a year that is nowhere near its worst.

The water supply half, in the past tense

What the agency forecast for Montana in 2026

This is the completed record of a finished season. The Natural Resources Conservation Service issues seasonal runoff volume forecasts for 85 points in Montana, monthly through the winter and spring, and each issue supersedes the last. Below are the biggest of those points and how each forecast moved as the snow year revealed itself.

The current runoff forecast is published by the agency; the most recent issue shown here is months old by definition, because the series closes in early summer. For the forecast that applies now, go to the agency, or to NOAA Missouri Basin River Forecast Center for river stage.

Lake Sakakawea Inflow

April 1 to July 31 runoff volume, thousands of acre feet. Normal for that period 9080. 2 issues on file for water year 2026.

03/01

04/01

normal 9080

The bar is the range the agency published at each issue, from the ninety percent exceedence value at the bottom to the ten percent value at the top, with the fifty percent value marked. An exceedence probability is the chance the actual volume exceeds that number, so ninety is the low end and ten is the high end. The fifty percent figure moved from 8710 on the March 1 issue to 6910 on the April 1 issue, or 96 percent of normal down to 76 percent. Those are the agency’s numbers for a season that has finished; the current forecast is on the agency’s own site.

Clark Fork R nr Plains

April 1 to July 31 runoff volume, thousands of acre feet. Normal for that period 8890. 2 issues on file for water year 2026.

03/01

04/01

normal 8890

The bar is the range the agency published at each issue, from the ninety percent exceedence value at the bottom to the ten percent value at the top, with the fifty percent value marked. An exceedence probability is the chance the actual volume exceeds that number, so ninety is the low end and ten is the high end. The fifty percent figure moved from 8400 on the March 1 issue to 7720 on the April 1 issue, or 94 percent of normal down to 87 percent. Those are the agency’s numbers for a season that has finished; the current forecast is on the agency’s own site.

Kootenai R at Leonia

April 1 to July 31 runoff volume, thousands of acre feet. Normal for that period 6680. 4 issues on file for water year 2026.

01/01

02/01

03/01

04/01

normal 6680

The bar is the range the agency published at each issue, from the ninety percent exceedence value at the bottom to the ten percent value at the top, with the fifty percent value marked. An exceedence probability is the chance the actual volume exceeds that number, so ninety is the low end and ten is the high end. The fifty percent figure moved from 8320 on the January 1 issue to 6100 on the April 1 issue, or 125 percent of normal down to 91 percent. Those are the agency’s numbers for a season that has finished; the current forecast is on the agency’s own site.

Flathead Lake Inflow

April 1 to July 31 runoff volume, thousands of acre feet. Normal for that period 5670. 2 issues on file for water year 2026.

03/01

04/01

normal 5670

The bar is the range the agency published at each issue, from the ninety percent exceedence value at the bottom to the ten percent value at the top, with the fifty percent value marked. An exceedence probability is the chance the actual volume exceeds that number, so ninety is the low end and ten is the high end. The fifty percent figure moved from 5080 on the March 1 issue to 5110 on the April 1 issue, or 90 percent of normal down to 90 percent. Those are the agency’s numbers for a season that has finished; the current forecast is on the agency’s own site.

Libby Reservoir Inflow

April 1 to July 31 runoff volume, thousands of acre feet. Normal for that period 5460. 2 issues on file for water year 2026.

03/01

04/01

normal 5460

The bar is the range the agency published at each issue, from the ninety percent exceedence value at the bottom to the ten percent value at the top, with the fifty percent value marked. An exceedence probability is the chance the actual volume exceeds that number, so ninety is the low end and ten is the high end. The fifty percent figure moved from 5360 on the March 1 issue to 5220 on the April 1 issue, or 98 percent of normal down to 96 percent. Those are the agency’s numbers for a season that has finished; the current forecast is on the agency’s own site.

Flathead R at Columbia Falls

April 1 to July 31 runoff volume, thousands of acre feet. Normal for that period 4870. 2 issues on file for water year 2026.

03/01

04/01

normal 4870

The bar is the range the agency published at each issue, from the ninety percent exceedence value at the bottom to the ten percent value at the top, with the fifty percent value marked. An exceedence probability is the chance the actual volume exceeds that number, so ninety is the low end and ten is the high end. The fifty percent figure moved from 4170 on the March 1 issue to 3950 on the April 1 issue, or 86 percent of normal down to 81 percent. Those are the agency’s numbers for a season that has finished; the current forecast is on the agency’s own site.

Volumes are in thousands of acre feet, in the units the agency publishes. Each point’s forecast period is printed above its chart, because the period is not the same everywhere: the Southwest runs off earlier and its forecasts are issued for an earlier window. Volumes from different periods are not comparable.

Reading the number

What the Montana snowpack number shows

The peak date on this page is a median of medians. Across the 87 Montana stations that publish one, the individual median peak dates span 62 days, from March 6 to May 7. A low station on a south face and a high one in a north facing cirque are in different climates, and averaging them produces a date that describes neither.

9 of the 96 Montana stations have no 1991 to 2020 median at all, nearly always because they were installed too recently to have thirty years behind them. A station with no normal cannot be a percentage of one, so it appears on the map and in the table with its measurement and no percentage, and it is left out of the state total. The panel at the top of this page prints both counts.

The Montana forecast points in the runoff section publish only twice a season, in March and April, where Colorado points publish from January. That is the agency’s schedule, not a gap in our data.

How Montana sits against the rest of the network. Its middle station is at 6,830 ft, against 10,275 ft in Colorado and 1,345 ft in Alaska. Elevation is not a proxy for depth: the deepest packs in the country sit on some of the lowest stations, because a maritime climate delivers far more water per storm than a continental one.

A wide brown river running high and fast between forested banks with the current carrying debris in the foreground — Snowmelt in a channel. Between the measurement above and the water here sit spring temperature, rain falling on snow, dust darkening the surface and how dry the soil was before winter. That gap is why this page publishes the measurement and links the agencies that publish the forecast. “Yellowstone flood event 2022 Lamar River above the Confluence with the Yellowstone River” — Yellowstone National Park (NPS) — Public domain

Where to go for the official answer

Who publishes Montana water supply

Montana Department of Natural Resources and Conservation

The state department responsible for Montana water rights and drought reporting. It participates in the state drought committee that reads these numbers alongside reservoir and streamflow data.

Link loaded and answered on 2026-09-04.

NOAA Missouri Basin River Forecast Center

The National Weather Service river forecast centre covering Montana. River stage and flow forecasts are its product, and it is the place to look when the question is about a specific river rather than about snow.

Link loaded and answered on 2026-09-04.

Common questions

Montana snowpack FAQ

When does Montana snowpack usually peak?

Around April 20, taking the middle of the 87 Montana stations that publish a median peak date. That is a median of medians and no single basin hits it: across the state those station level peak dates run from March 6 to May 7, which is 62 days of spread inside one state, driven almost entirely by elevation and aspect. The typical melt out across the same stations is May 28. All of these are medians drawn from roughly four decades of record and none of them is a statement about this year.

How many snow stations does Montana have?

What is a normal Montana snowpack?

In water rather than in depth, the middle Montana station typically peaks at about 15.6 inches of water, and the deepest, Flattop Mtn. at 6,280 feet, typically peaks at 47.2 inches. Nationally the range across the 12 covered states runs from 6.7 inches in Arizona to 32 in Washington. A station’s own median is far more useful than a state one, which is why the table on this page gives every station its own.

Where does Montana snowmelt go?

Montana’s stations sit thousands of feet lower than Colorado’s, because the same climate arrives at a lower elevation this far north. A pack at 6,800 feet in Montana and one at 10,300 feet in Colorado can hold the same water, and the Montana one is far more exposed to a February thaw. The basins on this page are the six digit hydrologic units the federal station records carry, named from the United States Geological Survey boundary dataset, and the largest of them by station count is Pend Oreille.

Who publishes the official Montana water supply forecast?

The Natural Resources Conservation Service publishes seasonal runoff volume forecasts for 85 forecast points in Montana, and NOAA Missouri Basin River Forecast Center publishes river forecasts; both are linked from this page. What this page shows from that programme is the completed 2026 water year record, in the past tense, with the issue date printed on every number, so you can see how a forecast moved across a season. On Lake Sakakawea Inflow, the fifty percent forecast went from 8710 to 6910 thousand acre feet between the March 1 and April 1 issues, against a normal of 9080. For the current forecast, go to the agency.

Does this page tell me whether Montana is heading into a drought?

No. Snowpack is one input to that question and this page publishes the input. The others are how dry the soil was before the snow fell, how fast the spring warms, whether rain falls on the snow, and how much dust settles on the surface and darkens it. Two identical Montana snowpacks in two different years can deliver very different amounts of water for those reasons, which is precisely why the agency issues its runoff forecast monthly and revises it, as the 2026 arcs further down this page show rather than computing it once from a snow number. For Montana drought conditions themselves, the United States Drought Monitor is the published record and it is a different measurement from this one.

Why do some Montana stations have no percentage?

Two reasons, and the page distinguishes them. 9 of the 96 Montana stations have no 1991 to 2020 median at all, almost always because they were installed too recently to have thirty years behind them, and a station with no normal cannot be a percentage of one. Separately, a station reporting exactly zero water against a normal of an inch or more is held out, because in this network that pattern is usually a failed sensor. Measured against the agency’s own quality flags for March 15, 2026, that rule held out 0 Montana stations and the agency had independently flagged 0 of them as not valid.

How does Montana snowpack compare with the rest of the West?

On elevation, Montana’s middle station sits at 6,830 feet against 10,275 in Colorado and 1,345 in Alaska, and elevation is not a proxy for depth: the deepest packs in the country sit on some of the lowest stations, because a maritime climate delivers far more water per storm. On timing, Montana peaks around April 20 against March 2 in Arizona and April 20 in Montana. The hub page puts all 12 side by side.

A snow covered mountain peak rising above dark conifer forest with drifted snow in the foreground under a pale winter sky — High country snow in the Northern Rockies. Montana peaks later than almost anywhere else in the network, in the second half of April, because it is cold enough to keep accumulating well past the point where the Southwest has already begun to melt. “Winter at Mount Rainier (31961755392)” by Mount Rainier National Park from Ashford, WA, United States, CC BY 2.0

The same water, elsewhere on this site

Snow, melt and what happens after

Montana droughtWhat the soil and the reservoirs already lost. Dry soil before winter absorbs melt that would otherwise reach a river.Montana river levelsWhat this snow becomes, months later, at gauges on the rivers these basins feed.Montana ski seasonWhether the snow is skiable, which is a resort question about groomed terrain rather than a water one.Mountain passesSeveral of these stations sit at passes, which is why the same instruments turn up on both pages.

Avalanche forecasts for the layers inside this same snowpack are issued by named forecasters at the avalanche centres: avalanche forecasts by state.

Other Northern Rockies states with a network

Sources for this page

USDA NRCS Air and Water Database, daily snow water equivalent filesfederal, public domain Read 2026-09-04.
One file per calendar day carrying every station’s entire period of record for that day. Measured at 102,474 bytes and 0.17 seconds for September 3 and 192,640 bytes for March 15, keyless and open to any origin. This is the source of every reading on these pages.
USDA NRCS Air and Water Database REST APIfederal, public domain Read 2026-09-04.
The documented API behind the same database. Used to build the station inventory, to verify that the daily files decode correctly, and as the fallback when the daily files cannot be reached.
USDA NRCS report generatorfederal, public domain Read 2026-09-04.
The one source that emits NRCS’s own labelled percent of median. Used to prove our figures reproduce the agency’s: all 118 Colorado stations matched exactly on value, median and percentage for March 15, 2026. Too slow to read live, at 8.9 seconds for one state.
USDA NRCS interactive station mapfederal, public domain Read 2026-09-04.
The agency’s own live map of every station it operates. This is where a reader goes for the official current picture, and every page in this vertical links it.
USGS Watershed Boundary Datasetfederal, public domain Read 2026-09-04.
NRCS station records carry a bare twelve digit hydrologic unit code and no name. The basin names on these pages come from the USGS boundary dataset, which named all 96 six digit basins in the station inventory.
California Department of Water Resources, California Data Exchange Centerstate agency, linked not reproduced Read 2026-09-04.
California’s own snow survey and the authority for California snowpack. Its data cannot be read from a browser on this site because it sends no cross origin header on any endpoint tested, including the preflight. It is linked rather than reproduced, and the California page explains where the two networks disagree.

Snow water equivalent measurements on this page are federal records collected by the USDA Natural Resources Conservation Service and are in the public domain. Percentages use the 1991 to 2020 normals period. The Montana and basin totals are our arithmetic on those measurements and are not agency published indices. Water supply forecasts and runoff projections come from the agencies named above. Every state with a snowpack page →
Hero image: “Winter at Mount Rainier (31961755392)” by Mount Rainier National Park from Ashford, WA, United States, CC BY 2.0