Climate and average weather in Macomb

In Macomb, the summers are humid, hot, showery, and partly cloudy and the winters are very cold, snowy, and partly cloudy.

Best: mid August to mid October

Over the course of the year, the temperature in Macomb typically varies from 19°F to 85°F, and is rarely below 0°F or above 93°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Macomb for warm-weather activities are from early May to mid June and mid August to mid October.

Hottest
Jul
85°
Coldest
Jan
19°
Wettest
Jun
4.8 in
Driest
Jan
2.0 in
Rain / yr
38.6 in
111 wet days
Daylight
9.1–14.9 h
shortest–longest
Elevation
705 ft
40.5°N
Clearest
Sep
45% cloud

Macomb is city in and the county seat of McDonough County, Illinois, United States.

Density
644/km²
people per km²
Founded
1830

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

Macomb 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 mid August to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 4.5 months, from May 15 to September 28, with daily high temperatures above 72°F. The hottest month of the year in Macomb is July, with an average high of 85°F and low of 67°F.

The cool season lasts 3.0 months, from December 1 to February 28, with daily high temperatures below 43°F. The coldest month of the year in Macomb is January, with an average low of 19°F and high of 33°F.

Days typically run about 18°F warmer than nights, with the widest day–night swing (around 20°F) in September.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan3319
Feb3822
Mar5032
Apr6243
May7354
Jun8264
Jul8567
Aug8365
Sep7757
Oct6445
Nov5034
Dec3824

How hot and cold Macomb 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 7°F (around January 17), with roughly 150 freezing days a year (feels-like at or below 32°F) 64 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)
Jan3333819
Feb38381222
Mar50502432
Apr62623843
May73735354
Jun82826464
Jul87856767
Aug84836565
Sep77775757
Oct64644145
Nov50502634
Dec38381524

Average hourly temperature in Macomb

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 85°F, and coldest before dawn in January, near 19°F.

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

Macomb 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
Jan33° / 19°2.07.64.99.40.0
Feb38° / 22°2.173.810.40.1
Mar50° / 32°2.99.6211.72.3
Apr62° / 43°4.611.90.4135.0
May73° / 54°4.713014.26.2
Jun82° / 64°4.811.7014.85.9
Jul85° / 67°3.39.7014.65.5
Aug83° / 65°3.29.1013.66.1
Sep77° / 57°3.47.6012.37.3
Oct64° / 45°2.88.50.210.95.9
Nov50° / 34°2.7819.82.3
Dec38° / 24°2.173.29.20.0

Chance of rain

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

Macomb gets about 38.6 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 4.3 months, from around Mar 16 to Jul 24, peaking in May at about 44% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 25.

June is the wettest month by volume, with 4.8 in over about 12 wet days; January is the driest, with 2.0 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetMay 1 · 44%Dec 25 · 22%
Rain on a day (%)Rain days
Jan248
Feb257
Mar3110
Apr4012
May4213
Jun3912
Jul3210
Aug299
Sep268
Oct279
Nov268
Dec237

Monthly rainfall

Over a full year, Macomb collects about 38.6 in of rain across 111 wet days — roughly 3.2 in in an average month.

It doesn’t fall evenly. June is the wettest month with 4.8 in, while January is the driest at just 2.0 in. The three wettest months alone bring about 36% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec2.02.12.94.64.74.83.33.23.42.82.72.1
Rainfall (in)Rain daysSnow days
Jan2.085
Feb2.174
Mar2.9102
Apr4.6120
May4.7130
Jun4.8120
Jul3.3100
Aug3.290
Sep3.480
Oct2.890
Nov2.781
Dec2.173

Snow in Macomb

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.

Macomb averages about 16 snowy days a year. Snow season runs roughly Oct 29 to Apr 15 — about 5.6 months.

January is snowiest, with roughly 5 days of snow and an estimated 8 in of snowfall. Over the year that adds up to an estimated 28 in of snow.

0246JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 20
Snow daysSnowfall (in)
Jan58
Feb47
Mar24
Apr02
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov12
Dec35

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

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

The clearer part of the year begins around June 4 and lasts for 4.7 months, ending around October 25. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 60% of the time on average.

The cloudier part of the year begins around October 26 and lasts for 7.3 months, ending around June 3. The cloudiest month is January, when it is overcast or mostly cloudy 64% 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%JanFebMarAprMayJunJulAugSepOctNovDecSep 4 · 63%Jan 1 · 36%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan3664
Feb3961
Mar3961
Apr3961
May4258
Jun5149
Jul5941
Aug6040
Sep6040
Oct5248
Nov4456
Dec3862

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 14, brings about 14 h 54 min of light; the shortest, around December 13, only 9 h 06 min — a swing of roughly 5 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.47:304:54
Feb10.47:055:29
Mar11.76:226:02
Apr13.05:316:35
May14.24:527:06
Jun14.84:377:29
Jul14.64:507:27
Aug13.65:186:55
Sep12.35:496:05
Oct10.96:215:15
Nov9.86:574:39
Dec9.27:254:33

Sunny days

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

Macomb 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 15 days.

The sunnier stretch runs 5.1 months, from around Jun 14 to Nov 15. The sunniest month is September, with roughly 15 sunny days (mixed).

The greyest month is April, down near 8 sunny days — about 47% fewer than the September peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightSep 815 daysApr 287 days
Sunny daysSky
Jan8Gloomy
Feb7Mixed
Mar8Gloomy
Apr8Gloomy
May8Gloomy
Jun10Mixed
Jul13Mixed
Aug13Mixed
Sep14Mixed
Oct13Mixed
Nov10Mixed
Dec8Mixed

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 Macomb, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.2 months, from around May 17 to September 22. The muggiest month is July, when the air feels humid, muggy or worse about 79% of the time.

The most comfortable stretch runs from around September 23 to May 16, and March 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%JanFebMarAprMayJunJulAugSepOctNovDecMar 5 · 100%Jul 18 · 18%oppressivemuggydrycomfortablehumidcomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan10000000
Feb10000000
Mar9820000
Apr9172000
May611714800
Jun22192227100
Jul6162429241
Aug11182627171
Sep4620161530
Oct8594100
Nov9820000
Dec9910000

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 Macomb is typically light breeze, near 8 mph, and varies moderately with the seasons.

The windier part of the year lasts 7.5 months, from around Oct 5 to May 19. The windiest month is April, averaging about 9 mph (light breeze).

The calmer part of the year runs from around May 20 to Oct 4, with August the calmest month at about 6 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyApr 9 · 9 mphAug 3 · 6 mph
Wind speed (mph)Feels
Jan9light breeze
Feb9light breeze
Mar9light breeze
Apr9light breeze
May8light breeze
Jun7calm
Jul6calm
Aug6calm
Sep7calm
Oct8light breeze
Nov9light breeze
Dec9light breeze

Best time to visit Macomb

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid August, Macomb 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 times of year to visit Macomb for general outdoor tourist activities run from early May to mid June and again from mid August to mid October, with a peak score in the last week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationSep 24 · 7.4

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
Jan0.0poor
Feb0.1poor
Mar2.3poor
Apr5.0fair
May6.2good
Jun5.9good
Jul5.5fair
Aug6.1good
Sep7.2good
Oct5.9good
Nov2.3poor
Dec0.1poor

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 Macomb for hot-weather activities is from early June to late September, with a peak score in the first week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 4 · 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 Macomb, 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 85°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 33°F), pack a warm layer and a heavy coat.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Macomb sees daytime highs around 85°F and nights near 67°F. Pack light clothes and sun protection. Worth having: rain gear. About 10 days see rain.

UV index (midday) in Macomb 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 Macomb peaks around June 19 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 19UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7High
Oct3Moderate
Nov3Moderate
Dec2Low

Average hourly UV index in Macomb

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 5.5 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
Mar50
Apr6.50.5
May7.54
Jun8.55.5
Jul85
Aug7.54
Sep62
Oct30
Nov00
Dec00

Air quality in Macomb 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 Macomb is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodJul 1815 µg/m³Oct 227 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar12Good
Apr10Good
May13Moderate
Jun13Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct7Good
Nov8Good
Dec9Good
Almanac & agriculture

Growing season

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

The growing season in Macomb typically lasts about 251 days, from around March 15 to November 20 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 17 to October 19.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 1550%Apr 1790%Oct 1990%Nov 2050%
Frost-free chance (%)Frost nights
Jan1431
Feb2028
Mar5131
Apr8816
May990
Jun1000
Jul1000
Aug1000
Sep1000
Oct919
Nov5630
Dec2431

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. Macomb banks about 3,368 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,0004,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr91
May410
Jun678
Jul805
Aug740
Sep500
Oct145
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.

Macomb receives about 4.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.8 and 6.6 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 19 to Sep 26. The brightest month is June, averaging about 6.4 kWh/m² (intense).

The dimmest month is December, down near 1.8 kWh/m² — roughly 72% less than the June peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 306.6 kWhDec 181.8 kWh
Solar energy (kWh/m²)Level
Jan2.1Moderate
Feb3.0Moderate
Mar4.1Bright
Apr5.0Bright
May5.8Bright
Jun6.4Intense
Jul6.4Intense
Aug5.7Bright
Sep4.7Bright
Oct3.3Moderate
Nov2.2Moderate
Dec1.8Dim

Where is Macomb?

Macomb sits at 40.5°N, 90.7°W, 705 ft above sea level, in United States. The nearest listed city is Burlington, 34 mi away.

Topography around Macomb

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

Within 2 miles, the terrain around Macomb has only modest variations in elevation — a maximum elevation change of 141 ft around an average of 682 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 256 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 472 ft.

The land around Macomb is covered by trees (32%), cropland (27%) and grassland (23%) within 2 miles, cropland (73%) within 10 miles, and cropland (63%) and trees (27%) within 50 miles.

2 miles
141 ft
10 miles
256 ft
50 miles
472 ft
treesgrasslandcroplandartificial surfaceswater
Nearby: Burlington 34 mi · Galesburg 37 mi · Quincy 53 mi · Pekin 55 mi · Jacksonville 55 mi · East Peoria 59 mi · Peoria 59 mi · North Peoria 60 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 Macomb (40.4592°, -90.6718°, elevation 705 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).