PlainClimate
NOAA 1991–2020 normals Incorporated place · exact Census match 1 NOAA station · Primary-station record

Joliet, MT Climate: Temperature & Rain by Month

Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score

30-year climate normals (1991-2020) from Joliet's primary NOAA station, JOLIET.

The climate verdict for Joliet

Dryness leads the climate profile for Joliet, Montana, with 14.5 inches of precipitation a year. NOAA records an annual average of 44°F. At 34/100 (below average) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 2% of scores.

44°F
yearly average temperature, NOAA normal
34/100
comfort score, above 2% of station-mapped location scores
14.5"
annual precipitation · 51" snow
109 days
frost-free growing season

Joliet: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.

Normals record plate

Sheet USC00244506 · Joliet, MT 44°F mean · 14.5" precip

TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-MID · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL

Nearest mean-temperature peer: Conrad, MT (+ 0 °F mean)

Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.

Mean-temperature neighbourhood

Nationwide NOAA normal poles and nearest peers, not a reprint of every MT station list.

Joliet sits in Montana, the #6 coldest U.S. state at 43.4°F statewide annual average - see all 50 coldest states ranked by NOAA normals

Climate Living Index · Joliet

Joliet: 14/100 · grade F

Joliet publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.

F
14/100Climate Living Index

PlainClimate-derived for Joliet, not an official NOAA rating. Rankings still use Comfort Score 34/100 (separate formula). Breakpoints and limits.

Joliet Living Index dimension scores
DimensionStation valueScore
Precipitation balance 14.5 in · 20.5 from 35 in 27/100 · F
Snowfall burden 50.9 inches/year 20/100 · F
Annual temperature balance 43.7°F · 23.8° from 67.5°F 15/100 · F
Normal heat + freeze calendar 211 calendar days 9/100 · F
Frost-free season 109 days/year 2/100 · F

Joliet · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.

Joliet is a continental Köppen climate: Dfb

Coldest-month mean 22.9°F and warmest-month mean 67.8°F place this station in continental, no dry season, warm summer climates (Dfb). Class Dfb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, no dry season, warm summer.

Köppen code
Dfb
Group
Continental
Warmest month
67.8°F
Coldest month
22.9°F

Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.

National standing · heating-led station

Where Joliet sits across the climate record

Three NOAA fields for Joliet's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.

Annual temperature
Cooler than 86%
Among 6,861 stations, Joliet sits in the cooler third of annual means.
Annual precipitation
Drier than 84%
Joliet's annual total ranks in the drier third of 6,352 measured normals.
Seasonal temperature swing
58th percentile swing
Typical seasonal amplitude versus 6,861 complete station-years.

How Joliet compares across U.S. station-mapped locations

Joliet's comfort score vs. all station-mapped locations

PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals

34 2nd percentile score exceeds 2% of 6,189 station-mapped location scores

0–10: 0 station-mapped locations (0%). Below this entry. 10–20: 0 station-mapped locations (0%). Below this entry. 20–30: 96 station-mapped locations (2%). Below this entry. 30–40: 280 station-mapped locations (5%). This entry sits in this band. 40–50: 1,113 station-mapped locations (18%). Above this entry. 50–60: 1,329 station-mapped locations (21%). Above this entry. 60–70: 1,236 station-mapped locations (20%). Above this entry. 70–80: 650 station-mapped locations (11%). Above this entry. 80–90: 921 station-mapped locations (15%). Above this entry. 90–100: 564 station-mapped locations (9%). Above this entry. This location 0 100 every station-mapped location, bucketed by value
  1. 0–10: 0 station-mapped locations (0%). Below this entry.
  2. 10–20: 0 station-mapped locations (0%). Below this entry.
  3. 20–30: 96 station-mapped locations (2%). Below this entry.
  4. 30–40: 280 station-mapped locations (5%). This entry sits in this band.
  5. 40–50: 1,113 station-mapped locations (18%). Above this entry.
  6. 50–60: 1,329 station-mapped locations (21%). Above this entry.
  7. 60–70: 1,236 station-mapped locations (20%). Above this entry.
  8. 70–80: 650 station-mapped locations (11%). Above this entry.
  9. 80–90: 921 station-mapped locations (15%). Above this entry.
  10. 90–100: 564 station-mapped locations (9%). Above this entry.

Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020

Each bar is a band; taller bars hold more station-mapped locations. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Joliet's measured station temperature trend

Methodology

Across 48 complete annual observations from 1957 to 2020, JOLIET warmed at a fitted rate of 0.19°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.

Joliet fitted annual mean temperature change, 1957-2020 Fitted station-temperature change from 1957 to 2020, relative to the fitted first year. The linear trend warmed at 0.19 °C per decade. -0.2°C +0.3°C +0.8°C +1.3°C 1960198020002020
  • Joliet primary station fitted change +0.19 °C/decade
Source: NOAA GHCN-M v4, quality-controlled monthly mean temperature. PlainClimate fits ordinary least squares over complete calendar years; minimum 30 years, record must reach 2015 or later.

Monthly Temperatures

Average daily high and low temperatures by month

Month Avg High Avg Low Mean
January 36°F (2°C) 10°F (-12°C) 23°F (-5°C)
February 39°F (4°C) 12°F (-11°C) 25°F (-4°C)
March 49°F (9°C) 19°F (-7°C) 34°F (1°C)
April 57°F (14°C) 27°F (-3°C) 42°F (5°C)
May 66°F (19°C) 36°F (2°C) 51°F (11°C)
June 76°F (24°C) 44°F (7°C) 60°F (16°C)
July 86°F (30°C) 50°F (10°C) 68°F (20°C)
August 84°F (29°C) 48°F (9°C) 66°F (19°C)
September 74°F (23°C) 39°F (4°C) 57°F (14°C)
October 59°F (15°C) 29°F (-2°C) 44°F (7°C)
November 45°F (7°C) 19°F (-7°C) 32°F (0°C)
December 36°F (2°C) 11°F (-12°C) 23°F (-5°C)

The year, day by day

Summer here tops out rather than builds: the warmest normal high is 88°F around July 25, short of 90°F on every date, while 211 dates carry a normal low at or below freezing, the coldest 9°F near January 1.

Normal daily high and low temperature for Joliet, January through December Peaks 88°F around July 25. Bottoms 9°F around January 1. 0 20 40 60 80 freezing JanFebMarAprMayJunJulAugSepOctNovDec
Normal daily high and low across the calendar year. NOAA 1991–2020 daily normals, JOLIET.

The freezing stretch

The normal low stays at or below 32°F into May 4, then returns to freezing around October 7, covering 211 dates in all.

Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.

Where the wet dates fall

The likeliest wet date is May 24, when 37% of years recorded at least a hundredth of an inch. The driest is January 16 at 15%. Summed across the calendar, that is about 81 wet dates a year.

The widest day

August 1 carries the biggest normal gap between afternoon and dawn, 37°F between the normal high and the normal low.

Look up any date

Any date's 1991–2020 normal for Joliet.

Where Joliet Stands Nationally

Winters bite deep and often: the normal nightly low dips to freezing or below on around 211 nights a year, placing this among the most frost-prone tenth of ranked stations.

Day-to-night contrast is extreme by national standards — the widest normal daily swing reaches about 37°F, sharper than nine in ten ranked stations see.

Joliet earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.

Monthly Precipitation

Average monthly rainfall and snowfall

January 0.5"

Snow: 7.7"

4.7 days with precipitation

February 0.6"

Snow: 9.5"

4.8 days with precipitation

March 0.8"

Snow: 8.0"

6.2 days with precipitation

April 1.9"

Snow: 4.1"

8.7 days with precipitation

May 2.7"

Snow: 0.8"

11.0 days with precipitation

June 2.1"

9.6 days with precipitation

July 0.9"

6.7 days with precipitation

August 0.9"

5.6 days with precipitation

September 1.3"

Snow: 0.4"

6.4 days with precipitation

October 1.6"

Snow: 4.8"

7.1 days with precipitation

November 0.7"

Snow: 6.5"

4.9 days with precipitation

December 0.6"

Snow: 9.1"

5.1 days with precipitation

Joliet spreads its precipitation across the year

Neither half of the year dominates here: June through August take 27% of the annual total and December through February 12%, with neither reaching the 35% that would mark a distinct wet season. Joliet has no dry season to plan around, though it does carry a 44.9°F seasonal spread.

The gap between the wettest and driest month still matters: May averages 2.7" and January 0.5". The three wettest months together take 46% of the year, against the 25% a perfectly flat distribution would give them.

Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.

Joliet is dry, and what does fall arrives gently

Only about 81 days a year record measurable precipitation here, 22% of the calendar, and they carry 14.5" between them. At roughly 0.18 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.

The wettest month by count is May at about 11 wet days; the driest is January at about 5.

A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.

A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.

Winter brings real snow to Joliet

Joliet averages 50.9 inches of snowfall a year, with February the snowiest month on the normals, spread across roughly 26 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.

NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.

Frost Dates & Growing Season

First Fall Freeze

September 15

50% probability date

Last Spring Freeze

May 29

50% probability date

Growing Season

109 days

Heating & Cooling Degree Days

Annual totals indicate energy demand for heating and cooling

Heating Degree Days

7,999

Higher = more heating needed

Cooling Degree Days

266

Higher = more cooling needed

Warmest Month

July

Coldest Month

January

Nationwide similar cities

Other rankable U.S. places outside MT closest to Joliet on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.

Closest by average temperature

Nearest out-of-state peers by annual mean temperature (44°F here).

Closest by annual precipitation

Nearest out-of-state peers by annual precipitation (14.5" here), excluding temperature-peer places.

Montana climate overview →

Snow and freeze rhythm

When cold and snow define Joliet

heating led · dry · mid swing

Joliet's energy balance leans toward cold weather: 7,999 annual heating degree days against 266 for cooling. Its 44.9°F seasonal range still makes the monthly rows more useful than the annual average alone.

Only about 109 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.

  1. 1. Joliet coldest normal

    January

    Averaging 23°F (-5°C), this month sits below freezing for the month as a whole, not merely overnight.

  2. 2. Joliet typical freeze period

    January through December

    The station reports average freezing days from January through December.

  3. 3. Joliet snow peak

    February

    Joliet averages 50.9 inches of snow a year, with February the snowiest month on the normals.

Questions about Joliet's climate

How much snow does Joliet get?
Joliet averages 50.9 inches of snow a year, most of it in February, within 14.5 inches of total precipitation. Snowfall is depth on the ground; the precipitation total counts its liquid equivalent, so the two are not additive.
How cold does Joliet get in winter?
Joliet records about 185 days a year with a low at or below freezing, with January the coldest month on the normals, and an annual average daily low of 29°F.
How much energy does heating and cooling require in Joliet?
Joliet has 7,999 heating degree days and 266 cooling degree days annually, a heating-dominated climate. Degree-day definitions: reading weather data.

Data Sources

Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Joliet's primary station: JOLIET (USC00244506). For informational purposes only.

Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 3039700). Match rule for Joliet: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.

Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate

On this page every temperature, precipitation, and derived score for Joliet comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.