Climate and average weather in Siegen

In Siegen, the summers are mild, showery, and partly cloudy and the winters are cold, snowy, and mostly cloudy.

Best: mid May to late September

Over the course of the year, the temperature in Siegen typically varies from -2°C to 22°C, and is rarely below -10°C or above 29°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 Siegen for warm-weather activities is from mid May to late September.

Hottest
Jul
22°
Coldest
Jan
-2°
Wettest
Dec
109 mm
Driest
Apr
62 mm
Rain / yr
984 mm
158 wet days
Daylight
7.7–16.3 h
shortest–longest
Elevation
272 m
50.9°N
Clearest
Aug
63% cloud

Siegen 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 late September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.7 months, from May 24 to September 13, with daily high temperatures above 18°C. The hottest month of the year in Siegen is July, with an average high of 22°C and low of 13°C.

The cool season lasts 3.6 months, from November 16 to March 6, with daily high temperatures below 6°C. The coldest month of the year in Siegen is January, with an average low of -2°C and high of 3°C.

Days typically run about 7°C warmer than nights, with the widest day–night swing (around 9°C) in July.

-10°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3-1
Feb4-2
Mar81
Apr134
May178
Jun2011
Jul2213
Aug2113
Sep1710
Oct126
Nov73
Dec30

How hot and cold Siegen 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°C (around January 26), with roughly 148 freezing days a year (feels-like at or below 0°C), worst in January.

-10°10°20°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan33-6-1
Feb44-6-2
Mar88-31
Apr131314
May171768
Jun20201111
Jul22221313
Aug21211313
Sep1717810
Oct121236
Nov77-13
Dec33-50

Average hourly temperature in Siegen

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 22°C, and coldest before dawn in January, near -2°C.

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

Siegen 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 / -2°10014.65.78.20.0
Feb / -2°79125.99.70.0
Mar / 8213.73.611.51.2
Apr13° / 6211.7113.53.3
May17° / 7212.6015.24.9
Jun20° / 11°7612.8016.25.7
Jul22° / 13°8314.2015.86.0
Aug21° / 13°8113.1014.36.0
Sep17° / 10°7611.6012.45.1
Oct12° / 8012.90.110.42.9
Nov / 8513.42.18.70.7
Dec / -0°10915.86.17.80.0

Chance of rain

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

Siegen gets about 984 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 3.3 months, from around Dec 2 to Mar 10, peaking in December at about 54% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Apr 14.

December is the wettest month by volume, with 109 mm over about 16 wet days; April is the driest, with 62 mm. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetDec 24 · 54%Apr 14 · 37%
Rain on a day (%)Rain days
Jan4715
Feb4412
Mar4314
Apr3912
May4113
Jun4313
Jul4514
Aug4313
Sep4012
Oct4113
Nov4513
Dec5016

Monthly rainfall

Over a full year, Siegen collects about 984 mm of rain across 158 wet days — roughly 82 mm in an average month.

It doesn’t fall evenly. December is the wettest month with 109 mm, while April is the driest at just 62 mm. The three wettest months alone bring about 30% of the year’s total, and some of the cold-season precipitation falls as snow.

0255075100125150JanFebMarAprMayJunJulAugSepOctNovDec10079826272768381768085109
Rainfall (mm)Rain daysSnow days
Jan100156
Feb79126
Mar82144
Apr62121
May72130
Jun76130
Jul83140
Aug81130
Sep76120
Oct80130
Nov85132
Dec109166

Snow in Siegen

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.

Siegen averages about 25 snowy days a year. Snow season runs roughly Nov 1 to Apr 26 — about 5.8 months.

January is snowiest, with roughly 6 days of snow and an estimated 22 cm of snowfall. Over the year that adds up to an estimated 101 cm of snow.

0246810JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 28
Snow daysSnowfall (cm)
Jan622
Feb626
Mar411
Apr15
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov210
Dec628

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Siegen, 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 March 12 and lasts for 6.6 months, ending around September 29. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 39% of the time on average.

The cloudier part of the year begins around September 30 and lasts for 5.4 months, ending around March 11. 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%JanFebMarAprMayJunJulAugSepOctNovDecAug 2 · 44%Dec 24 · 14%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2080
Feb2476
Mar3070
Apr3565
May3169
Jun3367
Jul3961
Aug3961
Sep3466
Oct2674
Nov1882
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 16, brings about 16 h 18 min of light; the shortest, around December 15, only 7 h 42 min — a swing of roughly 8 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan8.28:324:43
Feb9.77:525:33
Mar11.56:526:23
Apr13.55:427:15
May15.24:468:03
Jun16.24:208:36
Jul15.84:378:30
Aug14.35:217:43
Sep12.46:116:34
Oct10.47:005:25
Nov8.77:544:32
Dec7.88:324:16

Sunny days

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

Siegen 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 7 days.

The sunnier stretch runs 2.8 months, from around Mar 10 to Jun 1. The sunniest month is April, with roughly 7 sunny days (gloomy).

The greyest month is November, down near 3 sunny days — about 61% fewer than the April peak.

0510JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedApr 217 daysNov 232 days
Sunny daysSky
Jan4Gloomy
Feb4Gloomy
Mar6Gloomy
Apr7Gloomy
May6Gloomy
Jun5Gloomy
Jul6Gloomy
Aug6Gloomy
Sep6Gloomy
Oct5Gloomy
Nov3Gloomy
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 Siegen, the air stays dry or comfortable essentially all year. Even in July, the muggiest month, it feels humid or worse only about 9% of the time — humidity is not something you need to plan around here.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecMay 1 · 100%Jul 26 · 88%humidcomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)
Jan10000
Feb10000
Mar10000
Apr10000
May9451
Jun76195
Jul60319
Aug60319
Sep86131
Oct9730
Nov10000
Dec10000

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 Siegen is typically calm, near 12 km/h, and varies little with the seasons.

The windier part of the year lasts 5.8 months, from around Oct 12 to Apr 6. The windiest month is January, averaging about 14 km/h (light breeze).

The calmer part of the year runs from around Apr 7 to Oct 11, with August the calmest month at about 10 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeJan 5 · 14 km/hAug 1 · 10 km/h
Wind speed (km/h)Feels
Jan14light breeze
Feb13light breeze
Mar13light breeze
Apr11calm
May11calm
Jun11calm
Jul10calm
Aug10calm
Sep11calm
Oct12light breeze
Nov13light breeze
Dec13light breeze

Best time to visit Siegen

TravelBeach/poolTemperatureCloudsPrecipitation

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

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

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationAug 4 · 6.2

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
Mar1.2poor
Apr3.3poor
May4.9fair
Jun5.7good
Jul6.0good
Aug6.0good
Sep5.1fair
Oct2.9poor
Nov0.7poor
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 Siegen 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 1 · 4.6

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 Siegen, 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 22°C), the essentials are rain gear and sun protection. In the cold season around January (highs near 3°C), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Siegen sees daytime highs around 22°C and nights near 13°C. Pack rain gear. Worth having: sun protection. About 14 days see rain.

UV index (midday) in Siegen 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 Siegen peaks around July 14 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJul 14UV 7Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr4Moderate
May6High
Jun6High
Jul7High
Aug6High
Sep4Moderate
Oct2Moderate
Nov1Low
Dec1Low

Average hourly UV index in Siegen

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 July the burn window is concentrated in the middle of the day: about 7.5 hours a day reach index 3 (protection recommended), and 3 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
Mar10
Apr50
May70
Jun7.52.5
Jul7.53
Aug6.50
Sep40
Oct00
Nov00
Dec00
Almanac & agriculture

Growing season

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

The growing season in Siegen typically lasts about 278 days, from around March 5 to December 7 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 22 to November 2.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 550%Apr 2290%Nov 290%Dec 750%
Frost-free chance (%)Frost nights
Jan3831
Feb3828
Mar6231
Apr8622
May990
Jun1000
Jul1000
Aug1000
Sep1000
Oct950
Nov7525
Dec4731

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. Siegen banks about 786 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
Apr2
May74
Jun159
Jul227
Aug217
Sep100
Oct6
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.

Siegen receives about 3.0 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.6 and 5.3 kWh/m².

The brighter stretch of the year lasts 5.9 months, from around Mar 21 to Sep 17. The brightest month is June, averaging about 5.3 kWh/m² (bright).

The dimmest month is December, down near 0.6 kWh/m² — roughly 88% less than the June peak.

0123456JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightJun 265.3 kWhDec 220.6 kWh
Solar energy (kWh/m²)Level
Jan0.8Dim
Feb1.6Dim
Mar2.8Moderate
Apr4.4Bright
May5.0Bright
Jun5.3Bright
Jul5.1Bright
Aug4.5Bright
Sep3.0Moderate
Oct1.8Dim
Nov0.9Dim
Dec0.6Dim

Where is Siegen?

Siegen sits at 50.9°N, 8.0°E, 272 m above sea level, in Germany. The nearest listed city is Netphen, 7.0 km away.

Topography around Siegen

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

Within 3 km, the terrain around Siegen has only modest variations in elevation — a maximum elevation change of 202 m around an average of 312 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 509 m; within 80 km, large variations in elevation — a maximum elevation change of 850 m.

The land around Siegen is covered by trees (66%) and artificial surfaces (28%) within 3 km, trees (76%) within 16 km, and trees (59%) and grassland (20%) within 80 km.

3 km
202 m
16 km
509 m
80 km
850 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Netphen 7.0 km · Wilnsdorf 8.0 km · Kreuztal 11 km · Freudenberg 11 km · Hilchenbach 15 km · Haiger 20 km · Olpe 21 km · Dillenburg 24 km

Germany travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 80% of US
price level, 2025
GDP per capita
$60,496
2025
Happiness
6.9 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
0.9
per 100k, 2023
Road deaths
3.8
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 615
Religion
none 44%Roman Catholic 25%Protestant 23%other 5%

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 Siegen (50.8748°, 8.0243°, elevation 272 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).