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Koszalin weather by month — averages, rainfall & climate trends

Average temperatures and rainfall by month, a climate graph, today's conditions versus the long-term average, and how the climate has shifted since 1940 — all on one page for Koszalin, Poland.

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

17.2°

15°feels like
66%humidity
11°dew point
17 km/hfrom W
sunrise04:59sunset21:03day length16h 04m
TodayPartly cloudy18°16°
TuePartly cloudy20°15°
WedOvercast26°15°
ThuClear32°17°
FriOvercast24°18°
SatPartly cloudy25°15°
SunClear22°12°

On this date — July 27

Today (forecast)
18° / 16°
Average for July 27
21° / 14°

Cooler than usual · 3.2°C below the average high

  • Record high: 30.4° · 1946
  • Record low: 10.0° · 1998
  • One year ago: 21.9°

Every July 27 in history — coldest to hottest

Daily highsDaily lows

Dots show daily highs (top) and lows (bottom) for each July 27 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell — about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Koszalin is sampled from the ECMWF ERA5 reanalysis at 54.19°N, 16.17°E, with daily records since 1940.

Coordinates
54.19°N, 16.17°E
Time zone
Europe/Warsaw
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

14 of the last 31 days were warmer than the historical average for that date. Average difference: +0.9°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year — the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis — modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month — what a typical year looks like, from the full record.

Climate overview

Average temperatures in Koszalin follow a clear seasonal rhythm, rising and falling by 18.2°C over the course of the year. July brings the year's peak warmth: daily means of 17.5°C, with afternoons typically reaching 20.7°C. Roughly 20 days a year now top 25°C. The coolest month is January, when daily means fall to about -0.7°C and overnight lows sit around -2.8°C.

Rainfall is spread quite evenly across the year. The yearly total for Koszalin comes to about 776 mm; monthly amounts range from 47 mm in April up to 92 mm in July.

Over the full record (since 1940), the annual mean temperature in Koszalin has risen by 2.3°C between its first decade and its last. Frost days have thinned out, from around 100 a year in the first decade to about 55 now.

Climate graph (climograph)

July is the warmest month, January the coolest — a yearly swing of 18°C. Wettest month: July (~92 mm). Whole year averages ~776 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre — a measured proxy for how sunny the month is.

Koszalin month by month — what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainDaylightRecord highRecord low
January1.1°-2.8°60 mm7.6 h14.6° (2023)-27.1° (1942)
February1.8°-2.7°49 mm9.5 h16.2° (2021)-26.3° (1956)
March5.3°-0.6°50 mm11.5 h21.3° (1968)-20.4° (1986)
April10.2°3.0°47 mm13.8 h26.7° (1968)-7.6° (1944)
May15.1°7.2°58 mm15.8 h28.8° (1971)-2.8° (1971)
June18.7°11.2°70 mm16.9 h33.4° (2019)2.1° (2023)
July20.7°13.6°92 mm16.4 h33.7° (1994)6.4° (1995)
August20.8°13.5°82 mm14.6 h35.2° (1992)4.5° (1973)
September17.2°10.5°74 mm12.4 h29.8° (2019)1.0° (1966)
October12.1°6.6°65 mm10.2 h24.4° (1966)-5.4° (1956)
November6.4°2.6°64 mm8.2 h18.4° (1968)-11.3° (1998)
December2.9°-0.6°63 mm7.1 h13.1° (2022)-19.0° (1969)

How it has changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +2.3°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.28°C per decade.

One point per year — the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis — modelled estimates, not station readings.

Seasonal warming

Dec–Feb is warming fastest: +0.45°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis — modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 25°C per year: 8.6 early in the record → 18.6 recently. Frost days: 101 → 53.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

All-time high in 1992, all-time low in 1942: 35.2°C / -27.1°C.

One point per year — the single hottest and coldest day recorded that year.

Annual rainfall

~776 mm/year on average. Last decade ran +2% vs that average. Long-term trend: +13 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record — ~30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Koszalin — Frequently asked questions

Which is the warmest month in Koszalin?
On long-term average, the warmest month in Koszalin is July (mean about 17.5°C) and the coolest is January (about -0.7°C).
How does today's temperature in Koszalin compare to the historical average?
On 2026-07-27, Koszalin is forecast to reach a high of 18.2°C and a low of 15.5°C. The long-term average for this date (the full record since 1940) is a high of 21.4°C and a low of 14.0°C — today's high is 3.2°C cooler than that average.
How much has Koszalin warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Koszalin is about 2.3°C warmer.
How much does it rain in Koszalin?
Koszalin receives about 776 mm of precipitation per year on long-term average, with July typically the wettest month.
What is the average temperature in Koszalin?
Over the full record (since 1940), the annual mean temperature in Koszalin is about 8.3°C. The warmest month is July and the coolest is January.
What are the average temperatures in Koszalin by month?
Average daily highs and lows for each month in Koszalin (°C, full record since 1940): January 1°/-3°, February 2°/-3°, March 5°/-1°, April 10°/3°, May 15°/7°, June 19°/11°, July 21°/14°, August 21°/14°, September 17°/11°, October 12°/7°, November 6°/3°, December 3°/-1°.
How many days a year does it rain in Koszalin?
On long-term average, Koszalin has about 156 days a year with measurable rain, totalling roughly 776 mm.

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