Climate and average weather in Ostrów Mazowiecka

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

Best: early May to late September

Over the course of the year, the temperature in Ostrów Mazowiecka typically varies from -4°C to 24°C, and is rarely below -15°C or above 31°C. 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 Ostrów Mazowiecka for warm-weather activities is from early May to late September.

Hottest
Jul
24°
Coldest
Jan
-4°
Wettest
Jul
78 mm
Driest
Feb
37 mm
Rain / yr
633 mm
125 wet days
Daylight
7.4–16.6 h
shortest–longest
Elevation
122 m
52.8°N
Clearest
Aug
59% cloud

Ostrów Mazowiecka is city and urban gmina of Poland.

Density
1,030/km²
people per km²
Founded
1434

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

Ostrów Mazowiecka 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 early May to late September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.9 months, from May 17 to September 12, with daily high temperatures above 19°C. The hottest month of the year in Ostrów Mazowiecka is July, with an average high of 24°C and low of 14°C.

The cool season lasts 3.6 months, from November 19 to March 8, with daily high temperatures below 5°C. The coldest month of the year in Ostrów Mazowiecka is January, with an average low of -4°C and high of 0°C.

Days typically run about 8°C warmer than nights, with the widest day–night swing (around 11°C) in May.

-10°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan0-4
Feb1-4
Mar6-1
Apr133
May198
Jun2212
Jul2414
Aug2413
Sep189
Oct125
Nov61
Dec1-3

How hot and cold Ostrów Mazowiecka 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 -10°C (around January 27), with roughly 174 freezing days a year (feels-like at or below 0°C) 14 of them bitterly cold — worst in January.

-10°10°20°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan00-10-4
Feb11-9-4
Mar66-6-1
Apr131303
May191968
Jun22221112
Jul24241414
Aug23241313
Sep181879
Oct121225
Nov56-31
Dec11-8-3

Average hourly temperature in Ostrów Mazowiecka

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 24°C, and coldest before dawn in January, near -4°C.

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

Ostrów Mazowiecka weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -4°4010.46.57.90.0
Feb / -4°379.25.99.50.0
Mar / -1°409.93.511.50.6
Apr13° / 4610113.63.7
May19° / 6711.80.115.55.8
Jun22° / 12°7411.9016.56.2
Jul24° / 14°7812.4016.16.5
Aug24° / 13°6510.3014.56.8
Sep18° / 5810012.45.6
Oct12° / 469.50.410.33.1
Nov / 399.42.78.40.5
Dec / -3°4310.25.17.50.0

Chance of rain

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

Ostrów Mazowiecka gets about 633 mm 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 3.2 months, from around May 4 to Aug 8, peaking in June at about 42% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Oct 13.

July is the wettest month by volume, with 78 mm over about 12 wet days; February is the driest, with 37 mm. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 22 · 42%Oct 13 · 29%
Rain on a day (%)Rain days
Jan3210
Feb339
Mar3210
Apr3310
May3712
Jun4012
Jul3912
Aug3410
Sep3310
Oct3010
Nov329
Dec3310

Monthly rainfall

Over a full year, Ostrów Mazowiecka collects about 633 mm of rain across 125 wet days — roughly 53 mm in an average month.

It doesn’t fall evenly. July is the wettest month with 78 mm, while February is the driest at just 37 mm. The three wettest months alone bring about 34% of the year’s total, and some of the cold-season precipitation falls as snow.

0255075100JanFebMarAprMayJunJulAugSepOctNovDec403740466774786558463943
Rainfall (mm)Rain daysSnow days
Jan40107
Feb3796
Mar40104
Apr46101
May67120
Jun74120
Jul78120
Aug65100
Sep58100
Oct46100
Nov3993
Dec43105

Snow in Ostrów Mazowiecka

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.

Ostrów Mazowiecka averages about 25 snowy days a year. Snow season runs roughly Oct 19 to Apr 23 — about 6.1 months.

February is snowiest, with roughly 6 days of snow and an estimated 27 cm of snowfall. Over the year that adds up to an estimated 96 cm of snow.

02468JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonFeb 19
Snow daysSnowfall (cm)
Jan721
Feb627
Mar414
Apr14
May00
Jun00
Jul00
Aug00
Sep00
Oct02
Nov39
Dec520

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Ostrów Mazowiecka, 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 March 26 and lasts for 6.7 months, ending around October 15. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 47% of the time on average.

The cloudier part of the year begins around October 16 and lasts for 5.3 months, ending around March 25. The cloudiest month is December, when it is overcast or mostly cloudy 85% 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%JanFebMarAprMayJunJulAugSepOctNovDecApr 28 · 49%Dec 13 · 13%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan1981
Feb1981
Mar2872
Apr4060
May4456
Jun4159
Jul4555
Aug4753
Sep3862
Oct3169
Nov1783
Dec1585

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 13, brings about 16 h 36 min of light; the shortest, around January 1, only 7 h 24 min — a swing of roughly 9 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan7.97:453:38
Feb9.57:024:32
Mar11.55:575:27
Apr13.64:436:23
May15.53:437:15
Jun16.53:147:51
Jul16.13:337:43
Aug14.54:216:52
Sep12.45:155:39
Oct10.36:084:26
Nov8.47:063:29
Dec7.57:473:10

Sunny days

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

Ostrów Mazowiecka averages about 5 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 9 days.

The sunnier stretch runs 6.8 months, from around Mar 23 to Oct 15. The sunniest month is April, with roughly 7 sunny days (gloomy).

The greyest month is December, down near 2 sunny days — about 68% fewer than the April peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedApr 309 daysDec 132 days
Sunny daysSky
Jan3Gloomy
Feb3Gloomy
Mar5Gloomy
Apr7Gloomy
May8Gloomy
Jun6Gloomy
Jul7Gloomy
Aug8Mixed
Sep7Gloomy
Oct5Gloomy
Nov3Gloomy
Dec2Gloomy

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 Ostrów Mazowiecka, how humid it feels changes noticeably over the year.

The more humid part of the year lasts 3.1 months, from around May 31 to September 2. The muggiest month is July, when the air feels humid, muggy or worse about 23% of the time.

The most comfortable stretch runs from around September 3 to May 30, 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 26 · 100%Jul 30 · 71%humidcomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)
Jan100000
Feb100000
Mar100000
Apr100000
May91810
Jun7019101
Jul4631185
Aug5330153
Sep841420
Oct98200
Nov100000
Dec100000

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 Ostrów Mazowiecka is typically light breeze, near 13 km/h, and varies little with the seasons.

The windier part of the year lasts 6.1 months, from around Sep 30 to Apr 4. The windiest month is January, averaging about 15 km/h (light breeze).

The calmer part of the year runs from around Apr 5 to Sep 29, with August the calmest month at about 11 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeJan 29 · 15 km/hAug 2 · 11 km/h
Wind speed (km/h)Feels
Jan15light breeze
Feb14light breeze
Mar14light breeze
Apr12light breeze
May12calm
Jun12calm
Jul11calm
Aug11calm
Sep12light breeze
Oct13light breeze
Nov14light breeze
Dec14light breeze

Best time to visit Ostrów Mazowiecka

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid May, Ostrów Mazowiecka 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 18°C and 28°C. Based on this score, the best time of year to visit Ostrów Mazowiecka for general outdoor tourist activities is from early May to late September, with a peak score in the second week of August.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationAug 14 · 6.9

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
Mar0.7poor
Apr3.6fair
May5.8good
Jun6.2good
Jul6.6good
Aug6.7good
Sep5.6good
Oct3.1poor
Nov0.5poor
Dec0.0poor

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Ostrów Mazowiecka for hot-weather activities is from early July to late August, with a peak score in the first week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 7 · 6.0

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 Ostrów Mazowiecka, 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 24°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 0°C), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Ostrów Mazowiecka sees daytime highs around 24°C and nights near 14°C. Worth packing: light clothes, rain gear and sun protection. About 12 days see rain.

UV index (midday) in Ostrów Mazowiecka 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 Ostrów Mazowiecka peaks around June 20 at about 6 (high) — a little sun protection helps at midday. It bottoms out near December 19 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 20UV 6Dec 19UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr4Moderate
May5High
Jun6High
Jul6High
Aug6High
Sep4Moderate
Oct2Low
Nov1Low
Dec1Low

Average hourly UV index in Ostrów Mazowiecka

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 7.5 hours a day reach index 3 (protection recommended). 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
Mar00
Apr4.50
May6.50
Jun7.50
Jul70
Aug6.50
Sep40
Oct00
Nov00
Dec00
Almanac & agriculture

Growing season

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

The growing season in Ostrów Mazowiecka typically lasts about 242 days, from around March 26 to November 22 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 26 to October 12.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 2650%Apr 2690%Oct 1290%Nov 2250%
Frost-free chance (%)Frost nights
Jan2331
Feb2428
Mar4131
Apr8027
May980
Jun1000
Jul1000
Aug1000
Sep990
Oct8721
Nov5930
Dec3131

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Ostrów Mazowiecka banks about 944 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

02004006008001,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar0
Apr5
May105
Jun198
Jul273
Aug255
Sep105
Oct3
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.

Ostrów Mazowiecka receives about 2.9 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.5 and 5.6 kWh/m².

The brighter stretch of the year lasts 5.8 months, from around Mar 22 to Sep 15. The brightest month is June, averaging about 5.4 kWh/m² (bright).

The dimmest month is December, down near 0.5 kWh/m² — roughly 91% less than the June peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 55.6 kWhDec 160.5 kWh
Solar energy (kWh/m²)Level
Jan0.7Dim
Feb1.4Dim
Mar2.7Moderate
Apr4.2Bright
May5.2Bright
Jun5.5Bright
Jul5.3Bright
Aug4.4Bright
Sep2.9Moderate
Oct1.7Dim
Nov0.8Dim
Dec0.5Dim

Where is Ostrów Mazowiecka?

Ostrów Mazowiecka sits at 52.8°N, 21.9°E, 122 m above sea level, in Poland. The nearest listed city is Zambrów, 31 km away.

OstrołękaŁomżaSokołów PodlaskiPułtuskWołominŁapy

Topography around Ostrów Mazowiecka

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ostrów Mazowiecka.

Within 3 km, the terrain around Ostrów Mazowiecka has only modest variations in elevation — a maximum elevation change of 41 m around an average of 130 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 89 m; within 80 km, only modest variations in elevation — a maximum elevation change of 167 m.

The land around Ostrów Mazowiecka is covered by trees (41%) and cropland (25%) within 3 km, trees (43%), cropland (29%) and grassland (25%) within 16 km, and trees (36%), cropland (35%) and grassland (28%) within 80 km.

3 km
41 m
16 km
89 m
80 km
167 m
treesgrasslandcroplandartificial surfaces
Nearby: Zambrów 31 km · Wyszków 38 km · Ostrołęka 38 km · Łomża 43 km · Sokołów Podlaski 50 km · Pułtusk 56 km · Wołomin 68 km · Łapy 70 km

Poland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 52% of US
price level, 2025
GDP per capita
$28,420
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
0.8
per 100k, 2023
Road deaths
9.4
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 600
Religion
Roman Catholic 71%refused to answer 21%no religion 7%

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 Ostrów Mazowiecka (52.8025°, 21.8951°, elevation 122 m), 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).