Montana

Joliet, Montana Climate

NOAA 1991-2020 normals for Joliet, 3.4 km from Joliet

The warmest month is July, with an average high of 86°F; the coldest is January, with an average low of 10°F. A normal year brings 14.5 in of precipitation and 50.9 in of snow.

Temperature through the year

The normal daily high and low and the record for every date at Laurel (6S8), since 1999. The line marks today.

Normal daily high and low temperature at Joliet through the year, in °F, with the record for each date.-50050100150JanFebMarAprMayJunJulAugSepOctNovDec
  • Normal low
  • Normal high
  • Record high
  • Record low

Normals for Sep 24

Normal high
70°F
Normal low
37°F
Record high
94°Fin 2020
Record low
26°Fin 2000
Chance of a wet day
23%
Daylight
12 h 03 min

Month by month

Averages for 1991-2020. Wet days have at least 0.01 inch of precipitation. Freeze nights have a low of 32°F or colder; degree days are on a 65°F base. Each month links to its own page.

MonthAvg highAvg lowRecord highRecord lowPrecipitationWet daysSnowfallFreeze nightsHeating DDCooling DD
January36°F10°F67°F (2015)-31°F (2024)0.53 in4.77.7 in29.41,3070
February39°F12°F71°F (2015)-28°F (2025)0.57 in4.89.5 in26.21,1120
March49°F19°F86°F (2026)-21°F (2014)0.84 in6.28.0 in27.39600
April57°F27°F90°F (2012)-2°F (2002)1.89 in8.74.1 in20.07040
May66°F36°F99°F (2026)23°F (2005)2.67 in11.00.8 in6.64362
June76°F44°F108°F (2021)33°F (2008)2.11 in9.60.0 in0.417426
July86°F50°F115°F (2026)41°F (1999)0.94 in6.70.0 in0.038124
August84°F48°F109°F (2026)36°F (2015)0.88 in5.60.0 in0.16397
September74°F39°F107°F (2022)26°F (2000)1.26 in6.40.4 in2.727116
October59°F29°F93°F (2011)2°F (2020)1.57 in7.14.8 in16.86610
November45°F19°F79°F (2020)-17°F (2010)0.70 in4.96.5 in25.79870
December36°F11°F74°F (2021)-26°F (2022)0.58 in5.19.1 in29.41,2880
Year59°F29°F14.54 in8150.9 in1857,999266

Precipitation

Rain and melted snow together. The chance of a wet day is the share of days with at least 0.01 inch of precipitation.

14.5 in in a normal year, most in May.

Chance of a wet day

The chance of at least 0.01 inch of precipitation on each date at Joliet, in percent, and of at least 0.1 inch of snowfall.010203040JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day
  • Chance of snowfall

Snow

NOAA 1991-2020 snowfall normals for Joliet.

50.9 in of snow in a normal year.

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Joliet. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around May 29 and the first fall freeze around September 15, a growing season of about 107 days.

Median at 36°F
last June 13, first September 4
Median at 32°F
last May 29, first September 15
Median at 28°F
last May 13, first September 26

Frost dates, growing season and degree days

Humidity and comfort

NASA POWER reanalysis, 1991-2020, for the grid cell around Joliet.

Days with a mean dew point of 65°F or more are rare here in every month.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January17°F71%100%0%0%0%0%0%
February18°F67%100%0%0%0%0%0%
March23°F63%100%0%0%0%0%0%
April29°F61%100%0%0%0%0%0%
May37°F58%100%0%0%0%0%0%
June44°F55%98%2%0%0%0%0%
July48°F47%90%9%1%0%0%0%
August45°F44%96%4%0%0%0%0%
September37°F49%100%0%0%0%0%0%
October30°F59%100%0%0%0%0%0%
November22°F65%100%0%0%0%0%0%
December17°F70%100%0%0%0%0%0%

Comfort is judged by the day's mean dew point: dry below 55°F, comfortable to 60°F, humid to 65°F, muggy to 70°F, oppressive to 75°F, miserable above.

Clouds

Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.

The clearest month is July, with the sky 47 percent covered on average; the cloudiest is April, at 71 percent.

Wind

The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.

The windiest month is January, averaging 9.6 mph at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 18, with 15 h 41 min of daylight; the shortest is Dec 18, with 8 h 42 min.

Hours of daylight at Joliet through the year.0510152025JanFebMarAprMayJunJulAugSepOctNovDec
  • Day length

Solar energy

Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.

Sunrise and sunset calendar

How Carbon County is running

NOAA NCEI Climate at a Glance, from the nClimGrid analysis of every station, updated early each month. A rank of 1 is the highest or lowest of all years since 1895.

August 2026 in Carbon County: 67.0°F (+2.2 °F against 1991-2020), the 10th warmest in 132 years on record.

August 2026 in Carbon County: 1.22 in (+0.22 in against 1991-2020), the 55th wettest in 132 years on record.

January to August 2026 in Carbon County: 49.6°F (+4.3 °F against 1991-2020), the warmest in 132 years on record.

January to August 2026 in Carbon County: 9.79 in (-2.63 in against 1991-2020), the 15th driest in 132 years on record.

Warmest August
69.4°F in 2003
Coolest August
58.4°F in 1911
Wettest August
3.18 in in 1968
Driest August
0.12 in in 1897

Every year since 1895

Each year's average temperature in Carbon County against the 1991-2020 average, in °F, 1895 to 2025.-7.5-5-2.50+2.5+5+7.51900192019401960198020002020NOAA NCEI Climate at a Glance

Montana climate and rankings

Month pages

The weather in Joliet in each month, day by day.

What this means

A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.

A record is the highest or lowest value on the date in every year the station has reported, back to 1999. It rests on one station, so a neighbor a few miles away can hold different ones.

Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.

More for this place

Nearby

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00244506 (Joliet), public domain. Records: NOAA GHCN-Daily, station USC00240801, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus. Rankings: NOAA NCEI Climate at a Glance, public domain.