Oswego in Winter

In winter (December, January and February), Oswego sees average daytime highs around 34°F and overnight lows near 20°F, with 6.3 in of precipitation over about 23 wet days across the season. It is the coldest season of the year and the driest season of the year.

Across winter, daytime highs hold fairly steady around 34°F. The sky is clear or mostly clear about 23% of the time across winter, and the air most often feels dry.

Winter is Oswego's weakest season of the year to visit on our travel score. For the whole year in context, see Oswego's year-round climate.

Avg daytime high
34°F
coldest season of the year
Avg overnight low
20°F
Precipitation
6.3 in
23 wet days
Avg wind
8 mph
Travel score
0.0
weakest season of the year
Months
Dec · Jan · Feb

Temperature in Oswego in Winter

Average highAverage lowShaded bands: 10–90% of days

Across winter, daytime highs hold fairly steady around 34°F.

A typical winter day in Oswego reaches about 34°F and drops to 20°F overnight. The warmest of the three months is December, the coolest January.

20°40°60°DecJanFeb

How winter really feels in Oswego

Once humidity and wind are folded in, winter brings about 0 days that feel above 90°F and 90 that feel at or below 32°F.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
90
74 feel bitter (≤ 14°F)

The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.

Oswego weather by month

How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan31° / 17°2.18.15.99.30.0
Feb35° / 20°2.074.610.30.0
Mar47° / 30°2.79.62.911.71.5
Apr59° / 40°4.411.80.913.14.3
May70° / 51°4.612.7014.36.0
Jun79° / 61°4.311.80156.3
Jul83° / 65°3.711.2014.75.9
Aug81° / 63°3.610.5013.76.5
Sep74° / 55°3.08.3012.37.1
Oct62° / 43°3.19.10.110.95.3
Nov47° / 33°2.58.21.29.61.7
Dec36° / 23°2.284.390.0

Cloud cover in Winter

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time across winter.

0%25%50%75%100%DecJanFeb

Chance of precipitation in Winter

Any precipitationSnow

Oswego gets around 6.3 in of rain and snow over 23 wet days across winter. The line is the day-by-day chance of measurable precipitation.

0%10%20%30%40%DecJanFeb

Humidity in Winter

DryComfortableHumidMuggyOppressiveMiserable

Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

0%25%50%75%100%DecJanFeb

Wind in Winter

Winds average 8 mph across winter.

051015DecJanFeb

Sunrise & sunset in Winter

DaylightNight

Daylight runs from about 9 h 12 min in early December to 10 h 54 min by late February. The lit band spans sunrise to sunset each day.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMDecJanFeb

Solar energy in Winter

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day across winter, about 2.2 kWh/m².

01234DecJanFeb
Planning a trip in winter

Is winter a good time to visit Oswego?

Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.

0.0
Sightseeing
4th-best month of the year
0.0
Beach & pool
4th-best month of the year

winter is a weaker month for outdoor sightseeing in Oswego.

What to pack for Oswego in Winter

From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In winter, Oswego sees daytime highs around 34°F and nights near 20°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 23 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Oswego in Winter

The nearest coast averages about 39°F across winter — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 40 mi away) is warmest in August at about 73°F and coldest in February near 36°F.

It's comfortable for a long swim from Jul 13 to Sep 15 — about 2.1 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar36Bracing
Apr39Bracing
May45Bracing
Jun57Bracing
Jul70Refreshing
Aug73Refreshing
Sep68Refreshing
Oct58Bracing
Nov49Bracing
Dec42Bracing

UV index in Oswego in Winter

LowModerateHighVery highExtreme

Clear-sky midday UV across winter averages around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Oswego peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 highHighModerateLowJun 20UV 9Dec 19UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun9Very high
Jul8Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Oswego in Winter

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.

Air quality in Oswego is worst in July — around 17 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJul 1817 µg/m³Oct 229 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar16Moderate
Apr14Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug16Moderate
Sep13Moderate
Oct9Good
Nov10Good
Dec11Good
Location & terrain

Where is Oswego?

Oswego sits at 41.7°N, 88.4°W, 640 ft above sea level, in United States. The nearest listed city is Montgomery, 3.1 mi away.

Topography around Oswego

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

Within 2 miles, the terrain around Oswego has only modest variations in elevation — a maximum elevation change of 115 ft around an average of 650 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 371 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 784 ft.

The land around Oswego is covered by trees (31%) and grassland (27%) within 2 miles, cropland (42%) and grassland (22%) within 10 miles, and cropland (54%) within 50 miles.

2 miles
115 ft
10 miles
371 ft
50 miles
784 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Winter weather nearby: Montgomery 3.1 mi · Aurora 5.6 mi · Yorkville 5.6 mi · Plainfield 8.7 mi · North Aurora 8.7 mi · Batavia 12 mi · Naperville 12 mi · Shorewood 14 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 Oswego (41.6828°, -88.3515°, elevation 640 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.