Climate and average weather in Portage

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

Best: mid May to early October

Over the course of the year, the temperature in Portage typically varies from 19°F to 81°F, and is rarely below 1°F or above 89°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 Portage for warm-weather activities is from mid May to early October.

Hottest
Jul
81°
Coldest
Jan
19°
Wettest
May
4.4 in
Driest
Feb
2.2 in
Rain / yr
39.8 in
132 wet days
Daylight
8.9–15.1 h
shortest–longest
Elevation
879 ft
42.2°N
Clearest
Sep
54% cloud

Portage is city in Kalamazoo County, Michigan, United States of America.

Density
529/km²
people per km²
Founded
1830

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

Portage 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 May to early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 4.3 months, from May 19 to September 25, with daily high temperatures above 69°F. The hottest month of the year in Portage is July, with an average high of 81°F and low of 63°F.

The cool season lasts 3.2 months, from December 1 to March 6, with daily high temperatures below 40°F. The coldest month of the year in Portage is January, with an average low of 19°F and high of 31°F.

Days typically run about 16°F warmer than nights, with the widest day–night swing (around 19°F) in September.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan3119
Feb3420
Mar4528
Apr5739
May6849
Jun7859
Jul8163
Aug7961
Sep7354
Oct6043
Nov4633
Dec3625

How hot and cold Portage 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 24), with roughly 164 freezing days a year (feels-like at or below 32°F) 71 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)
Jan3131819
Feb3434920
Mar45452028
Apr57573339
May68684749
Jun78785959
Jul82816363
Aug79796161
Sep73735354
Oct60603843
Nov46462633
Dec36361625

Average hourly temperature in Portage

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 19°F.

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

Portage 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
Jan31° / 19°2.811.310.49.30.0
Feb34° / 20°2.28.36.610.30.0
Mar45° / 28°2.710.24.411.61.0
Apr57° / 39°3.912.71.413.13.8
May68° / 49°4.413.1014.45.8
Jun78° / 59°4.311.70156.4
Jul81° / 63°4.011.4014.86.3
Aug79° / 61°3.811.1013.76.6
Sep73° / 54°3.19.7012.36.8
Oct60° / 43°3.4110.210.84.6
Nov46° / 33°2.810.139.61.3
Dec36° / 25°2.5117.990.0

Chance of rain

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

Portage gets about 39.8 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 3.3 months, from around Mar 27 to Jul 5, peaking in April at about 43% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Feb 9.

May is the wettest month by volume, with 4.4 in over about 13 wet days; February is the driest, with 2.2 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetApr 28 · 43%Feb 9 · 28%
Rain on a day (%)Rain days
Jan3611
Feb308
Mar3410
Apr4213
May4213
Jun3912
Jul3711
Aug3511
Sep3310
Oct3511
Nov3410
Dec3611

Monthly rainfall

Over a full year, Portage collects about 39.8 in of rain across 132 wet days — roughly 3.3 in in an average month.

It doesn’t fall evenly. May is the wettest month with 4.4 in, while February is the driest at just 2.2 in. The three wettest months alone bring about 32% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec2.82.22.73.94.44.34.03.83.13.42.82.5
Rainfall (in)Rain daysSnow days
Jan2.81110
Feb2.287
Mar2.7104
Apr3.9131
May4.4130
Jun4.3120
Jul4.0110
Aug3.8110
Sep3.1100
Oct3.4110
Nov2.8103
Dec2.5118

Snow in Portage

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.

Portage averages about 34 snowy days a year. Snow season runs roughly Oct 25 to Apr 25 — about 6 months.

January is snowiest, with roughly 10 days of snow and an estimated 15 in of snowfall. Over the year that adds up to an estimated 51 in of snow.

051015JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 16
Snow daysSnowfall (in)
Jan1015
Feb711
Mar46
Apr12
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov35
Dec812

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Portage, 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 April 16 and lasts for 6.2 months, ending around October 21. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 56% of the time on average.

The cloudier part of the year begins around October 22 and lasts for 5.8 months, ending around April 15. The cloudiest month is January, when it is overcast or mostly cloudy 84% 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 29 · 57%Jan 12 · 15%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan1684
Feb2476
Mar3466
Apr3763
May4159
Jun4852
Jul5644
Aug5446
Sep5347
Oct4357
Nov2872
Dec1882

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 15, brings about 15 h 06 min of light; the shortest, around December 14, only 8 h 54 min — a swing of roughly 6 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.38:145:29
Feb10.37:486:06
Mar11.67:036:41
Apr13.16:087:17
May14.45:277:50
Jun15.05:118:14
Jul14.85:248:12
Aug13.75:557:38
Sep12.36:286:45
Oct10.87:025:52
Nov9.67:415:14
Dec9.08:105:06

Sunny days

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

Portage 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 11 days.

The sunnier stretch runs 6.3 months, from around Apr 12 to Oct 19. The sunniest month is September, with roughly 11 sunny days (mixed).

The greyest month is January, down near 3 sunny days — about 74% fewer than the September peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedSep 311 daysJan 153 days
Sunny daysSky
Jan3Gloomy
Feb4Gloomy
Mar7Gloomy
Apr7Gloomy
May9Mixed
Jun9Mixed
Jul10Mixed
Aug11Mixed
Sep11Mixed
Oct9Mixed
Nov5Gloomy
Dec3Gloomy

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

The more humid part of the year lasts 3.9 months, from around May 25 to September 21. The muggiest month is July, when the air feels humid, muggy or worse about 62% of the time.

The most comfortable stretch runs from around September 22 to May 24, 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 6 · 100%Jul 20 · 35%oppressivemuggyhumiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan1000000
Feb1000000
Mar991000
Apr954100
May7514840
Jun352223172
Jul1622272410
Aug182725247
Sep53221591
Oct898210
Nov982000
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 Portage is typically light breeze, near 8 mph, and varies little with the seasons.

The windier part of the year lasts 7.4 months, from around Oct 6 to May 18. The windiest month is April, averaging about 8 mph (light breeze).

The calmer part of the year runs from around May 19 to Oct 5, with August the calmest month at about 6 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyApr 11 · 9 mphAug 7 · 6 mph
Wind speed (mph)Feels
Jan8light breeze
Feb8light breeze
Mar8light breeze
Apr8light breeze
May8light breeze
Jun7calm
Jul6calm
Aug6calm
Sep7calm
Oct8light breeze
Nov8light breeze
Dec8light breeze

Best time to visit Portage

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late May, Portage 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 Portage for general outdoor tourist activities is from mid May to early October, with a peak score in the first week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 6 · 7.0

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
Mar1.0poor
Apr3.8fair
May5.8good
Jun6.4good
Jul6.3good
Aug6.6good
Sep6.7good
Oct4.6fair
Nov1.4poor
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 Portage for hot-weather activities is from early June to mid September, with a peak score in the second week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 11 · 6.6

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 Portage, 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 31°F), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Portage sees daytime highs around 81°F and nights near 63°F. Pack light clothes and sun protection. Worth having: rain gear. About 11 days see rain.

Sea temperature near Portage

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea at the nearest coast (about 42 mi away) is warmest in August at about 72°F and coldest in March near 36°F.

It's comfortable for a long swim from Jul 14 to Sep 13 — about 2 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan39Bracing
Feb37Bracing
Mar36Bracing
Apr39Bracing
May45Bracing
Jun58Bracing
Jul69Refreshing
Aug72Refreshing
Sep68Cool
Oct59Bracing
Nov49Bracing
Dec43Bracing

UV index (midday) in Portage 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 Portage peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 9Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr6High
May7High
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Average hourly UV index in Portage

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
Mar40
Apr60
May7.53.5
Jun8.55.5
Jul8.55
Aug7.54
Sep5.50
Oct20
Nov00
Dec00

Air quality in Portage 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 Portage is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1515 µg/m³Oct 228 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar13Moderate
Apr12Moderate
May14Moderate
Jun15Moderate
Jul16Moderate
Aug15Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Almanac & agriculture

Growing season

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

The growing season in Portage typically lasts about 238 days, from around March 27 to November 19 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 26 to October 18.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 2750%Apr 2690%Oct 1890%Nov 1950%
Frost-free chance (%)Frost nights
Jan1331
Feb1328
Mar3631
Apr7823
May980
Jun1000
Jul1000
Aug1000
Sep990
Oct9010
Nov5530
Dec2331

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. Portage banks about 2,620 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr17
May274
Jun557
Jul687
Aug626
Sep392
Oct69
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.

Portage receives about 4.0 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 1.4 and 6.5 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 15 to Sep 22. The brightest month is July, averaging about 6.3 kWh/m² (intense).

The dimmest month is December, down near 1.4 kWh/m² — roughly 77% less than the July peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 16.5 kWhDec 181.4 kWh
Solar energy (kWh/m²)Level
Jan1.7Dim
Feb2.8Moderate
Mar4.0Bright
Apr5.0Bright
May5.8Bright
Jun6.4Intense
Jul6.3Intense
Aug5.3Bright
Sep4.3Bright
Oct2.9Moderate
Nov1.8Dim
Dec1.4Dim

Where is Portage?

Portage sits at 42.2°N, 85.6°W, 879 ft above sea level, in United States. The nearest listed city is Kalamazoo, 6.2 mi away.

Topography around Portage

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

Within 2 miles, the terrain around Portage has only modest variations in elevation — a maximum elevation change of 141 ft around an average of 876 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 358 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 679 ft.

The land around Portage is covered by trees (50%) and artificial surfaces (23%) within 2 miles, trees (48%) and cropland (24%) within 10 miles, and trees (42%) and cropland (37%) within 50 miles.

2 miles
141 ft
10 miles
358 ft
50 miles
679 ft
treesgrasslandcroplandartificial surfaceswaterwetland
Nearby: Kalamazoo 6.2 mi · Battle Creek 22 mi · Granger 41 mi · Elkhart 41 mi · Goshen 45 mi · Kentwood 47 mi · Mishawaka 48 mi · Holland 48 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 Portage (42.2011°, -85.58°, elevation 879 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).