Montana, 2021

Extreme Cold and Heavy Snow in Montana, December 26 to 30, 2021

December 26 to 30, 2021 · NWS TFX · 15 events in 14 counties and zones

An arctic cold front pushed into Montana the day after Christmas, bringing subzero temperatures and dangerous wind chills to the plains. Some areas also saw some snowfall as the cold air pushed into the area.

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
15

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS TFX wrote it up.

An arctic cold front pushed into Montana the day after Christmas, bringing subzero temperatures and dangerous wind chills to the plains. Some areas also saw some snowfall as the cold air pushed into the area. Some gusty winds occurred as the cold air made a temporary retreat, with isolated high winds across the area.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Great Falls, MT wrote its last area forecast discussion before the first event at Dec 25, 4:41 PM MST, 14 hours 49 minutes earlier.

Area forecast discussion, Dec 25, 4:41 PM MST, 14 hours 49 minutes before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Event by event

12 extreme cold/wind chill, 2 high wind, 1 heavy snow. Local standard time, as filed.

Heavy Snow, Gallatin

When
December 26, 7:30 AM MST to 12:11 PM MST
Where
Gallatin forecast zone
Reported by
Trained Spotter

Total snowfall of 6 inches since 730 am mst.

Extreme Cold/Wind Chill, Fergus

When
December 26, 9:00 AM MST
Where
Fergus forecast zone
Reported by
AWOS

AWOS station Oscar records wind chill of -47.

Extreme Cold/Wind Chill, Eastern Glacier

When
December 26, 9:00 AM MST
Where
Eastern Glacier forecast zone
Reported by
ASOS

Cut Bank airport reports wind chill of -41.

Extreme Cold/Wind Chill, Toole

When
December 26, 3:00 PM MST to December 27, 12:21 PM MST
Where
Toole forecast zone
Reported by
Mesonet

Multiple mesonet stations recorded wind chills between -40 and -50, with the coldest reading of -50 occurring 11 SSW of Whitlash at 12:21 pm on the 27th.

Extreme Cold/Wind Chill, Hill

When
December 26, 6:05 PM MST to December 27, 2:53 AM MST
Where
Hill forecast zone
Reported by
Mesonet

Multiple stations reported wind chills under -40. Coldest wind chill was a -48 wind chill recorded at a mesonet station 27 miles north of Havre at 2:46 am.

Extreme Cold/Wind Chill, Southern Rocky Mountain Front

When
December 26, 9:58 PM MST to December 27, 8:40 AM MST
Where
Southern Rocky Mountain Front forecast zone
Reported by
Mesonet

Multiple sensors across the Southern Rocky Mountain Front recorded wind chills between -40 and -44.

Extreme Cold/Wind Chill, Liberty

When
December 26, 10:30 PM MST
Where
Liberty forecast zone
Reported by
Mesonet

Mesonet stations around Joplin recorded wind chills around -45.

Extreme Cold/Wind Chill, Judith Basin

When
December 26, 11:30 PM MST to December 27, 1:06 AM MST
Where
Judith Basin forecast zone
Reported by
Mesonet

Two mesonet stations, at Geyser and Benchland, report wind chills between -40 and -42.

Extreme Cold/Wind Chill, Chouteau

When
December 26, 11:53 PM MST
Where
Chouteau forecast zone
Reported by
Mesonet

Mesonet station near Big Sandy recorded a wind gust of -43. Only report in the county.

Extreme Cold/Wind Chill, Eastern Pondera

When
December 27, 12:00 AM MST
Where
Eastern Pondera forecast zone
Reported by
Mesonet

Mesonet station 6 miles WNW of Ledger reports wind chill of -40.

Extreme Cold/Wind Chill, Blaine

When
December 27, 2:40 AM MST
Where
Blaine forecast zone
Reported by
AWOS

Awos station s719 chinook reports a wind chill of -45.

Extreme Cold/Wind Chill, North Rocky Mountain Front

When
December 27, 7:54 AM MST
Where
North Rocky Mountain Front forecast zone
Reported by
Mesonet

Meosnet station at Two Medicine Bridge recorded a wind chill of -40.

Extreme Cold/Wind Chill, Southern Lewis and Clark

When
December 27, 8:37 AM MST
Where
Southern Lewis and Clark forecast zone
Reported by
Mesonet

Bowmans Corner mesonet site records a wind chill of -41.

High Wind, Eastern Glacier

When
December 29, 10:19 PM MST
Where
Eastern Glacier forecast zone
Measured
51 kt (59 mph) measured gust
Reported by
ASOS

Cut Bank ASOS recorded a wind gust to 59 mph. This appears to have been an isolated gust in the area.

High Wind, Madison

When
December 30, 6:27 AM MST
Where
Madison forecast zone
Measured
52 kt (60 mph) measured gust
Reported by
Mesonet

Mesonet station at Norris Hill recorded a wind gust of 60 mph. This appears to have been an isolated report, with nearby stations recording wind gusts to around 50 mph.

What these are

Heavy Snow
Snowfall reaching the local warning threshold without the other hazards of a winter storm.
Extreme Cold/Wind Chill
Temperatures or wind chills at or below the local warning criteria, or cold that caused deaths.
High Wind
Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Montana in 2021Every state in 2021This day in weather historyWarnings in Montana, December 2021

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-30. Each event’s entry at NCEI: 996772, 999175, 999188, 999214, 999193, 999213, 999201, 999197, 999151, 999206, 999103, 999191, 999199, 999228, 999229.