Climate and average weather in Des Moines

In Des Moines, the summers are warm, fairly dry, and mostly clear and the winters are cold, snowy, and mostly cloudy.

Best: late June to mid September

Over the course of the year, the temperature in Des Moines typically varies from 38°F to 75°F, and is rarely below 29°F or above 85°F. August is the hottest month of the year, while December is the coldest.

Based on the travel score, the best time of year to visit Des Moines for warm-weather activities is from late June to mid September.

Hottest
Aug
75°
Coldest
Dec
38°
Wettest
Nov
7.6 in
Driest
Jul
1.0 in
Rain / yr
51.7 in
155 wet days
Daylight
8.2–15.8 h
shortest–longest
Elevation
92 ft
47.4°N
Clearest
Aug
44% cloud

Des Moines is city in King County, Washington, United States.

Density
1,854/km²
people per km²
Founded
1959

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

Des Moines 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 June to mid September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.0 months, from June 19 to September 17, with daily high temperatures above 68°F. The hottest month of the year in Des Moines is August, with an average high of 75°F and low of 58°F.

The cool season lasts 3.7 months, from November 14 to March 7, with daily high temperatures below 51°F. The coldest month of the year in Des Moines is December, with an average low of 38°F and high of 45°F.

Days typically run about 12°F warmer than nights, with the widest day–night swing (around 17°F) in August.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan4638
Feb4939
Mar5240
Apr5744
May6449
Jun6853
Jul7457
Aug7558
Sep6953
Oct5947
Nov5042
Dec4538

Average hourly temperature in Des Moines

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 August afternoons, near 75°F, and coldest before dawn in December, near 38°F.

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

Des Moines 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
Jan46° / 38°6.918.42.28.71.0
Feb49° / 39°4.714.51.89.91.6
Mar52° / 40°5.517.50.811.62.3
Apr57° / 44°4.514.90.113.33.5
May64° / 49°3.012014.95.3
Jun68° / 53°2.39.5015.76.3
Jul74° / 57°1.05015.37.9
Aug75° / 58°1.34.8014.18.0
Sep69° / 53°2.68.4012.46.8
Oct59° / 47°5.314.1010.64.2
Nov50° / 42°7.6180.69.11.9
Dec45° / 38°7.017.62.18.30.8

Chance of rain

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

Des Moines gets about 51.7 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 6.7 months, from around Oct 11 to May 2, peaking in November at about 61% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 1.

November is the wettest month by volume, with 7.6 in over about 18 wet days; July is the driest, with 1.0 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%70%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetNov 20 · 61%Aug 1 · 11%
Rain on a day (%)Rain days
Jan5818
Feb5415
Mar5518
Apr5015
May3912
Jun3210
Jul175
Aug155
Sep288
Oct4514
Nov5918
Dec5818

Monthly rainfall

Over a full year, Des Moines collects about 51.7 in of rain across 155 wet days — roughly 4.3 in in an average month.

It doesn’t fall evenly. November is the wettest month with 7.6 in, while July is the driest at just 1.0 in. The three wettest months alone bring about 42% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456789JanFebMarAprMayJunJulAugSepOctNovDec6.94.75.54.53.02.31.01.32.65.37.67.0
Rainfall (in)Rain daysSnow days
Jan6.9182
Feb4.7152
Mar5.5181
Apr4.5150
May3.0120
Jun2.3100
Jul1.050
Aug1.350
Sep2.680
Oct5.3140
Nov7.6181
Dec7.0182

Snow in Des Moines

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.

Des Moines averages about 8 snowy days a year. Snow season runs roughly Nov 15 to Mar 27 — about 4.4 months.

January is snowiest, with roughly 2 days of snow and an estimated 3 in of snowfall. Over the year that adds up to an estimated 12 in of snow.

01234JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 1
Snow daysSnowfall (in)
Jan23
Feb23
Mar11
Apr00
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov11
Dec23

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Des Moines, 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 15 and lasts for 3.9 months, ending around October 11. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 64% of the time on average.

The cloudier part of the year begins around October 12 and lasts for 8.1 months, ending around June 14. The cloudiest month is December, when it is overcast or mostly cloudy 79% 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 30 · 69%Dec 18 · 19%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2476
Feb2971
Mar2872
Apr3169
May3565
Jun4159
Jul6238
Aug6436
Sep5644
Oct3862
Nov2674
Dec2179

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 22, brings about 15 h 48 min of light; the shortest, around December 21, only 8 h 12 min — a swing of roughly 7 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan8.77:594:38
Feb9.97:255:22
Mar11.66:326:06
Apr13.35:286:51
May14.94:397:32
Jun15.74:188:01
Jul15.34:337:57
Aug14.15:117:16
Sep12.45:546:14
Oct10.66:365:12
Nov9.17:234:26
Dec8.37:574:14

Sunny days

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

Des Moines averages about 7 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 3 and 17 days.

The sunnier stretch runs 3.7 months, from around Jun 21 to Oct 10. The sunniest month is July, with roughly 14 sunny days (mixed).

The greyest month is December, down near 4 sunny days — about 73% fewer than the July peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightJul 2917 daysDec 183 days
Sunny daysSky
Jan4Gloomy
Feb5Gloomy
Mar5Gloomy
Apr5Gloomy
May6Gloomy
Jun7Gloomy
Jul14Mixed
Aug15Mixed
Sep12Mixed
Oct7Gloomy
Nov5Gloomy
Dec4Gloomy

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 Des Moines, the air stays dry or comfortable essentially all year. Even in August, the muggiest month, it feels humid or worse only about 7% of the time — humidity is not something you need to plan around here.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecApr 29 · 100%Aug 13 · 91%humidcomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)
Jan10000
Feb10000
Mar10000
Apr10000
May9730
Jun83161
Jul49465
Aug44497
Sep71272
Oct9460
Nov10000
Dec10000

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 Des Moines is typically calm, near 6 mph, and varies little with the seasons.

The windier part of the year lasts 6.1 months, from around Oct 15 to Apr 17. The windiest month is November, averaging about 7 mph (calm).

The calmer part of the year runs from around Apr 18 to Oct 14, with August the calmest month at about 4 mph.

0510JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeNov 24 · 7 mphAug 3 · 4 mph
Wind speed (mph)Feels
Jan6calm
Feb6calm
Mar6calm
Apr6calm
May5calm
Jun5calm
Jul4calm
Aug4calm
Sep5calm
Oct6calm
Nov7calm
Dec7calm

Hazard calendar for Des Moines

In seasonPeak

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

Des Moines's rainy season runs October–April, 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 Des Moines

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around early September, Des Moines is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

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 Des Moines for general outdoor tourist activities is from late June to mid September, with a peak score in the last week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 31 · 8.4

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
Jan1.0poor
Feb1.6poor
Mar2.3poor
Apr3.5fair
May5.3fair
Jun6.3good
Jul7.9ideal
Aug8.0ideal
Sep6.7good
Oct4.2fair
Nov1.9poor
Dec0.9poor

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 Des Moines for hot-weather activities is from mid July to late August, with a peak score in the first week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 1 · 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 Des Moines, 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 August (highs near 75°F), the essentials are light clothes and sun protection. In the cold season around December (highs near 45°F), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Des Moines sees daytime highs around 75°F and nights near 58°F. Worth packing: light clothes and sun protection. About 5 days see rain.

UV index (midday) in Des Moines 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 Des Moines peaks around July 17 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 18 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 17UV 8Dec 18UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar4Moderate
Apr5Moderate
May7High
Jun6High
Jul8Very high
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Average hourly UV index in Des Moines

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 July 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
Mar30
Apr50
May72.5
Jun70
Jul8.54.5
Aug6.50
Sep40
Oct00
Nov00
Dec00

Air quality in Des Moines by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Des Moines is worst in September — around 22 µg/m³ PM2.5 (moderate), about 3.4× the cleanest month (December, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodSep 1322 µg/m³Dec 177 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar12Moderate
Apr12Good
May11Good
Jun10Good
Jul10Good
Aug18Moderate
Sep22Moderate
Oct12Good
Nov8Good
Dec7Good
Almanac & agriculture

Growing season

Chance of a frost-free dayReliably frost-free (≥90%)

Des Moines is mild enough that a frost-free day stays more likely than not even in midwinter. Nights are reliably above freezing from about January 23 to November 28 (310 days); outside that window a hard frost is an occasional risk.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecreliably frost-freeJan 2390%Nov 2890%
Frost-free chance (%)Frost nights
Jan8727
Feb917
Mar970
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov956
Dec8731

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. Des Moines banks about 1,974 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

05001,0001,5002,0002,500JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr27
May195
Jun324
Jul492
Aug504
Sep334
Oct99
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.

Des Moines receives about 3.4 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.8 and 6.2 kWh/m².

The brighter stretch of the year lasts 6.0 months, from around Mar 26 to Sep 25. The brightest month is July, averaging about 6.1 kWh/m² (intense).

The dimmest month is December, down near 0.9 kWh/m² — roughly 86% less than the July peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 236.2 kWhDec 170.8 kWh
Solar energy (kWh/m²)Level
Jan1.0Dim
Feb1.9Dim
Mar3.0Moderate
Apr4.3Bright
May5.3Bright
Jun5.6Bright
Jul6.1Intense
Aug5.4Bright
Sep4.0Bright
Oct2.3Moderate
Nov1.2Dim
Dec0.9Dim

Where is Des Moines?

Des Moines sits at 47.4°N, 122.3°W, 92 ft above sea level, in United States. The nearest listed city is SeaTac, 3.7 mi away.

Topography around Des Moines

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

Within 2 miles, the terrain around Des Moines has only modest variations in elevation — a maximum elevation change of 489 ft around an average of 177 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 682 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 14,413 ft.

The land around Des Moines is covered by trees (36%), water (35%) and artificial surfaces (24%) within 2 miles, trees (43%), water (27%) and artificial surfaces (22%) within 10 miles, and trees (76%) within 50 miles.

2 miles
489 ft
10 miles
682 ft
50 miles
14,413 ft
treesgrasslandartificial surfacesbare terrainwater
Nearby: SeaTac 3.7 mi · Kent 4.3 mi · Burien 5.0 mi · Federal Way 5.6 mi · Tukwila 5.6 mi · East Hill-Meridian 6.8 mi · Bryn Mawr-Skyway 7.5 mi · Renton 7.5 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 Des Moines (47.4018°, -122.3243°, elevation 92 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. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).