Climate and average weather in Mandan

In Mandan, the summers are warm, showery, and mostly clear and the winters are very cold, snowy, and partly cloudy.

Best: late May to early October

Over the course of the year, the temperature in Mandan typically varies from 6°F to 81°F, and is rarely below -17°F or above 92°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Mandan for warm-weather activities is from late May to early October.

Hottest
Jul
81°
Coldest
Jan
Wettest
Jun
3.8 in
Driest
Jan
0.6 in
Rain / yr
21.3 in
83 wet days
Daylight
8.3–15.7 h
shortest–longest
Elevation
1,647 ft
46.8°N
Clearest
Aug
41% cloud

Mandan is city in North Dakota, United States.

Density
737/km²
people per km²
Founded
1881

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Mandan weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late May to early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Mandan, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.2 months, from May 19 to September 24, with daily high temperatures above 67°F. The hottest month of the year in Mandan is July, with an average high of 81°F and low of 59°F.

The cool season lasts 3.3 months, from November 27 to March 6, with daily high temperatures below 33°F. The coldest month of the year in Mandan is January, with an average low of 6°F and high of 22°F.

Days typically run about 20°F warmer than nights, with the widest day–night swing (around 24°F) in August.

-20°20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan226
Feb269
Mar3820
Apr5332
May6544
Jun7554
Jul8159
Aug8157
Sep7147
Oct5535
Nov3821
Dec2610

How hot and cold Mandan really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about -11°F (around January 10), with roughly 209 freezing days a year (feels-like at or below 32°F) 136 of them bitterly cold — worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan2222-96
Feb2626-59
Mar3838920
Apr53532332
May65653844
Jun75755454
Jul81815959
Aug81815757
Sep71714447
Oct55552735
Nov39381121
Dec2626-310

Average hourly temperature in Mandan

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 81°F, and coldest before dawn in January, near F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Mandan weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan22° / 0.64.54.98.80.0
Feb26° / 0.74.74.7100.0
Mar38° / 20°1.15.34.111.60.3
Apr53° / 32°1.97.7313.33.1
May65° / 44°2.910.30.414.85.8
Jun75° / 54°3.811.5015.66.6
Jul81° / 59°3.010015.36.7
Aug81° / 57°2.37.50147.2
Sep71° / 47°1.86.4012.47.3
Oct55° / 35°1.86.41.710.64.0
Nov38° / 21°0.84.23.59.20.2
Dec26° / 10°0.74.14.78.40.0

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Mandan gets about 21.3 in of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.

The wetter season lasts 4.4 months, from around Apr 9 to Aug 20, peaking in June at about 41% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 8.

June is the wettest month by volume, with 3.8 in over about 12 wet days; January is the driest, with 0.6 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 10 · 41%Dec 8 · 12%
Rain on a day (%)Rain days
Jan155
Feb165
Mar175
Apr268
May3410
Jun3812
Jul3210
Aug248
Sep226
Oct206
Nov144
Dec134

Monthly rainfall

Over a full year, Mandan collects about 21.3 in of rain across 83 wet days — roughly 1.8 in in an average month.

It doesn’t fall evenly. June is the wettest month with 3.8 in, while January is the driest at just 0.6 in. The three wettest months alone bring about 46% of the year’s total, and some of the cold-season precipitation falls as snow.

00.511.522.533.544.5JanFebMarAprMayJunJulAugSepOctNovDec0.60.71.11.92.93.83.02.31.81.80.80.7
Rainfall (in)Rain daysSnow days
Jan0.655
Feb0.755
Mar1.154
Apr1.983
May2.9100
Jun3.8120
Jul3.0100
Aug2.380
Sep1.860
Oct1.862
Nov0.844
Dec0.745

Snow in Mandan

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Mandan averages about 27 snowy days a year. Snow season runs roughly Oct 1 to May 14 — about 7.4 months.

December is snowiest, with roughly 5 days of snow and an estimated 7 in of snowfall. Over the year that adds up to an estimated 43 in of snow.

02468JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonDec 28
Snow daysSnowfall (in)
Jan57
Feb56
Mar47
Apr37
May01
Jun00
Jul00
Aug00
Sep00
Oct22
Nov46
Dec57

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Mandan, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around June 7 and lasts for 4.4 months, ending around October 19. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 72% of the time on average.

The cloudier part of the year begins around October 20 and lasts for 7.6 months, ending around June 6. The cloudiest month is February, when it is overcast or mostly cloudy 63% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecJul 27 · 74%Feb 27 · 35%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan3961
Feb3763
Mar4159
Apr4357
May4654
Jun5545
Jul7228
Aug7129
Sep6139
Oct5149
Nov4456
Dec4060

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 17, brings about 15 h 42 min of light; the shortest, around December 17, only 8 h 18 min — a swing of roughly 7 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan8.88:315:15
Feb10.07:585:58
Mar11.67:066:41
Apr13.36:037:24
May14.85:158:05
Jun15.64:558:33
Jul15.35:108:29
Aug14.05:477:49
Sep12.46:286:48
Oct10.67:105:47
Nov9.27:555:02
Dec8.48:294:50

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Mandan averages about 10 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 7 and 17 days.

The sunnier stretch runs 4.0 months, from around Jun 21 to Oct 19. The sunniest month is August, with roughly 16 sunny days (bright).

The greyest month is March, down near 8 sunny days — about 50% fewer than the August peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightAug 2317 daysMar 37 days
Sunny daysSky
Jan8Gloomy
Feb7Gloomy
Mar8Gloomy
Apr8Mixed
May9Mixed
Jun10Mixed
Jul16Bright
Aug16Bright
Sep14Mixed
Oct11Mixed
Nov9Mixed
Dec9Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Mandan, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 3.1 months, from around June 9 to September 9. The muggiest month is July, when the air feels humid, muggy or worse about 37% of the time.

The most comfortable stretch runs from around September 10 to June 8, and April is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecApr 28 · 100%Jul 16 · 60%muggyhumiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan1000000
Feb1000000
Mar1000000
Apr1000000
May936100
Jun64221050
Jul352824121
Aug49271950
Sep8411410
Oct1000000
Nov1000000
Dec1000000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Mandan is typically light breeze, near 10 mph, and varies little with the seasons.

The windier part of the year lasts 6.1 months, from around Nov 25 to May 28. The windiest month is January, averaging about 10 mph (light breeze).

The calmer part of the year runs from around May 29 to Sep 22, with July the calmest month at about 8 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyJan 23 · 10 mphJul 30 · 8 mph
Wind speed (mph)Feels
Jan10light breeze
Feb10light breeze
Mar10light breeze
Apr10light breeze
May10light breeze
Jun9light breeze
Jul8light breeze
Aug8light breeze
Sep9light breeze
Oct10light breeze
Nov10light breeze
Dec10light breeze

Hazard calendar for Mandan

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

Mandan's rainy season runs April–October, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Best time to visit Mandan

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Mandan throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late May, Mandan is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best time of year to visit Mandan for general outdoor tourist activities is from late May to early October, with a peak score in the first week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 4 · 7.6

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.0poor
Feb0.0poor
Mar0.3poor
Apr3.1poor
May5.8good
Jun6.6good
Jul6.8good
Aug7.2good
Sep7.2good
Oct3.9fair
Nov0.3poor
Dec0.0poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Mandan for hot-weather activities is from late June to mid September, with a peak score in the third week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 19 · 7.3

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Mandan, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 81°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 22°F), pack a warm layer and a heavy coat.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Mandan sees daytime highs around 81°F and nights near 59°F. Pack light clothes and sun protection. Worth having: rain gear. About 10 days see rain.

UV index (midday) in Mandan by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Mandan peaks around June 22 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 20 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 22UV 8Dec 20UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr4Moderate
May6High
Jun8Very high
Jul8Very high
Aug6High
Sep5High
Oct4Moderate
Nov2Low
Dec1Low

Average hourly UV index in Mandan

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 4.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb00
Mar2.50
Apr50
May70
Jun8.54.5
Jul84.5
Aug72
Sep5.50
Oct2.50
Nov00
Dec00
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Mandan typically lasts about 189 days, from around April 17 to October 22 — the span where a frost-free day is more likely than not. It is reliably frost-free from May 13 to September 29.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 510%Apr 1750%May 1390%Sep 2990%Oct 2250%Nov 2010%
Frost-free chance (%)Frost nights
Jan431
Feb528
Mar1531
Apr4930
May9212
Jun1000
Jul1000
Aug1000
Sep971
Oct6331
Nov1630
Dec531

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Mandan banks about 2,074 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

05001,0001,5002,0002,500JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr0
May148
Jun437
Jul632
Aug580
Sep271
Oct6
Nov0
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Mandan receives about 4.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.4 and 6.8 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Mar 16 to Sep 19. The brightest month is July, averaging about 6.7 kWh/m² (intense).

The dimmest month is December, down near 1.5 kWh/m² — roughly 78% less than the July peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 96.8 kWhDec 191.4 kWh
Solar energy (kWh/m²)Level
Jan1.8Dim
Feb2.8Moderate
Mar4.2Bright
Apr5.3Bright
May6.0Bright
Jun6.5Intense
Jul6.7Intense
Aug5.8Bright
Sep4.3Bright
Oct2.8Moderate
Nov1.9Dim
Dec1.4Dim

Where is Mandan?

Mandan sits at 46.8°N, 100.9°W, 1,647 ft above sea level, in United States. The nearest listed city is Bismarck, 5.0 mi away.

Topography around Mandan

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Mandan.

Within 2 miles, the terrain around Mandan has only modest variations in elevation — a maximum elevation change of 341 ft around an average of 1,709 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 499 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 899 ft.

The land around Mandan is covered by grassland (44%) and artificial surfaces (26%) within 2 miles, grassland (63%) and cropland (21%) within 10 miles, and grassland (63%) and cropland (33%) within 50 miles.

2 miles
341 ft
10 miles
499 ft
50 miles
899 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Bismarck 5.0 mi · Dickinson 90 mi · Minot 99 mi · Jamestown 103 mi · Aberdeen 149 mi · Williston 157 mi · West Fargo 188 mi · Fargo 194 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Mandan (46.8267°, -100.8896°, elevation 1,647 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).