Climate and average weather in Janakkala

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

Best: late May to early September

Over the course of the year, the temperature in Janakkala typically varies from -9°C to 21°C, and is rarely below -21°C or above 27°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 Janakkala for warm-weather activities is from late May to early September.

Hottest
Jul
21°
Coldest
Jan
-8°
Wettest
Jul
81 mm
Driest
Feb
31 mm
Rain / yr
609 mm
123 wet days
Daylight
5.2–18.8 h
shortest–longest
Elevation
118 m
60.9°N
Clearest
May
62% cloud

Janakkala 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 late May to early September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.8 months, from May 19 to September 10, with daily high temperatures above 15°C. The hottest month of the year in Janakkala is July, with an average high of 21°C and low of 13°C.

The cool season lasts 3.7 months, from November 22 to March 14, with daily high temperatures below 1°C. The coldest month of the year in Janakkala is January, with an average low of -8°C and high of -3°C.

Days typically run about 7°C warmer than nights, with the widest day–night swing (around 10°C) in May.

-20°-10°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan-3-8
Feb-3-9
Mar2-6
Apr80
May155
Jun1910
Jul2113
Aug2011
Sep147
Oct72
Nov2-1
Dec-1-5

How hot and cold Janakkala 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 -15°C (around January 31), with roughly 204 freezing days a year (feels-like at or below 0°C) 95 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)
Jan-3-3-13-8
Feb-3-3-14-9
Mar22-11-6
Apr88-40
May151535
Jun1919910
Jul21211313
Aug20201111
Sep141457
Oct77-12
Nov22-6-1
Dec-1-1-10-5

Average hourly temperature in Janakkala

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 21°C, and coldest before dawn in January, near -8°C.

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

Janakkala 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-3° / -8°409.710.16.10.0
Feb-3° / -9°3188.28.50.0
Mar / -6°328.17.611.30.0
Apr / -0°358.53.114.21.5
May15° / 4910.20.2174.4
Jun19° / 10°7612.3018.65.5
Jul21° / 13°8112.80186.0
Aug20° / 11°7112.2015.55.8
Sep14° / 5110.1012.64.0
Oct / 5410.51.59.71.0
Nov / -1°4710.35.170.0
Dec-1° / -5°4510.78.85.40.0

Chance of rain

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

Janakkala gets about 609 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 3.9 months, from around May 20 to Sep 14, peaking in June at about 44% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Mar 23.

July is the wettest month by volume, with 81 mm over about 13 wet days; February is the driest, with 31 mm. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 22 · 44%Mar 23 · 26%
Rain on a day (%)Rain days
Jan3210
Feb288
Mar278
Apr289
May3210
Jun4112
Jul4113
Aug3912
Sep3410
Oct3311
Nov3510
Dec3411

Monthly rainfall

Over a full year, Janakkala collects about 609 mm of rain across 123 wet days — roughly 51 mm in an average month.

It doesn’t fall evenly. July is the wettest month with 81 mm, while February is the driest at just 31 mm. The three wettest months alone bring about 37% of the year’s total, and some of the cold-season precipitation falls as snow.

0255075100JanFebMarAprMayJunJulAugSepOctNovDec403132354976817151544745
Rainfall (mm)Rain daysSnow days
Jan401010
Feb3188
Mar3288
Apr3593
May49100
Jun76120
Jul81130
Aug71120
Sep51100
Oct54112
Nov47105
Dec45119

Snow in Janakkala

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.

Janakkala averages about 45 snowy days a year. Snow season runs roughly Oct 6 to May 8 — about 7.1 months.

January is snowiest, with roughly 10 days of snow and an estimated 36 cm of snowfall. Over the year that adds up to an estimated 166 cm of snow.

0510JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 8
Snow daysSnowfall (cm)
Jan1036
Feb828
Mar827
Apr311
May02
Jun00
Jul00
Aug00
Sep00
Oct26
Nov521
Dec935

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Janakkala, 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 7 and lasts for 6.7 months, ending around September 26. The clearest month is May, when the sky is clear, mostly clear, or partly cloudy 40% of the time on average.

The cloudier part of the year begins around September 27 and lasts for 5.3 months, ending around March 6. The cloudiest month is November, when it is overcast or mostly cloudy 86% 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%JanFebMarAprMayJunJulAugSepOctNovDecMay 10 · 41%Nov 19 · 12%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan1684
Feb2179
Mar3268
Apr3466
May4060
Jun3664
Jul3961
Aug3466
Sep2971
Oct2377
Nov1486
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 18 h 48 min of light; the shortest, around December 16, only 5 h 12 min — a swing of roughly 13 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan6.19:293:33
Feb8.58:204:52
Mar11.36:526:10
Apr14.25:137:30
May17.03:488:48
Jun18.62:599:45
Jul18.03:269:28
Aug15.54:408:11
Sep12.65:596:33
Oct9.77:174:57
Nov7.08:413:33
Dec5.49:412:55

Sunny days

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

Janakkala 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 8 days.

The sunnier stretch runs 3.6 months, from around Mar 1 to Jun 18. The sunniest month is May, with roughly 7 sunny days (gloomy).

The greyest month is November, down near 2 sunny days — about 72% fewer than the May peak.

0510JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedMay 98 daysNov 222 days
Sunny daysSky
Jan3Gloomy
Feb4Gloomy
Mar7Gloomy
Apr6Gloomy
May8Gloomy
Jun5Gloomy
Jul6Gloomy
Aug5Gloomy
Sep5Gloomy
Oct4Gloomy
Nov2Gloomy
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 Janakkala, 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 10 · 100%Jul 27 · 87%humidcomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)
Jan100000
Feb100000
Mar100000
Apr100000
May98100
Jun89920
Jul613081
Aug653050
Sep93700
Oct100000
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 Janakkala is typically calm, near 12 km/h, and varies little with the seasons.

The windier part of the year lasts 6.5 months, from around Sep 20 to Apr 6. The windiest month is December, averaging about 13 km/h (light breeze).

The calmer part of the year runs from around Apr 7 to Sep 19, with July the calmest month at about 10 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeDec 25 · 13 km/hJul 28 · 10 km/h
Wind speed (km/h)Feels
Jan13light breeze
Feb12light breeze
Mar12light breeze
Apr11calm
May11calm
Jun11calm
Jul10calm
Aug10calm
Sep12calm
Oct12light breeze
Nov12light breeze
Dec13light breeze

Best time to visit Janakkala

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around early June, Janakkala 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 Janakkala for general outdoor tourist activities is from late May to early September, with a peak score in the last week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 29 · 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
Mar0.0poor
Apr1.5poor
May4.4fair
Jun5.5good
Jul6.0good
Aug5.8good
Sep4.0fair
Oct1.1poor
Nov0.0poor
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 Janakkala for hot-weather activities is from early July to mid August, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 27 · 4.1

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 Janakkala, 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 21°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, Janakkala sees daytime highs around 21°C and nights near 13°C. Worth packing: rain gear and sun protection. About 13 days see rain.

UV index (midday) in Janakkala 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 Janakkala peaks around June 18 at about 5 (high) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 4 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateModerateLowJun 18UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5High
Jul5Moderate
Aug4Moderate
Sep2Moderate
Oct1Low
Nov0Low
Dec0Low

Average hourly UV index in Janakkala

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 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
Apr00
May5.50
Jun70
Jul6.50
Aug50
Sep00
Oct00
Nov00
Dec00
Almanac & agriculture

Growing season

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

The growing season in Janakkala typically lasts about 201 days, from around April 18 to November 4 — the span where a frost-free day is more likely than not. It is reliably frost-free from May 15 to September 30.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonApr 1850%May 1590%Sep 3090%Nov 450%
Frost-free chance (%)Frost nights
Jan1431
Feb1328
Mar1631
Apr4730
May9114
Jun1000
Jul1000
Aug1000
Sep972
Oct7131
Nov3930
Dec2131

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. Janakkala banks about 562 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

0200400600JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar0
Apr0
May21
Jun129
Jul212
Aug169
Sep31
Oct0
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.

Janakkala receives about 2.5 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.1 and 5.4 kWh/m².

The brighter stretch of the year lasts 5.7 months, from around Mar 22 to Sep 9. The brightest month is June, averaging about 5.3 kWh/m² (bright).

The dimmest month is December, down near 0.1 kWh/m² — roughly 98% less than the June peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 35.4 kWhDec 180.1 kWh
Solar energy (kWh/m²)Level
Jan0.2Dim
Feb0.8Dim
Mar2.2Moderate
Apr3.7Moderate
May5.1Bright
Jun5.3Bright
Jul5.0Bright
Aug3.8Moderate
Sep2.2Moderate
Oct1.0Dim
Nov0.3Dim
Dec0.1Dim

Where is Janakkala?

Janakkala sits at 60.9°N, 24.6°E, 118 m above sea level, in Finland. The nearest listed city is Hämeenlinna, 13 km away.

Topography around Janakkala

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

Within 3 km, the terrain around Janakkala has only modest variations in elevation — a maximum elevation change of 68 m around an average of 98 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 108 m; within 80 km, only modest variations in elevation — a maximum elevation change of 225 m.

The land around Janakkala is covered by trees (57%) and cropland (27%) within 3 km, trees (67%) within 16 km, and trees (71%) within 80 km.

3 km
68 m
16 km
108 m
80 km
225 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Hämeenlinna 13 km · Riihimäki 20 km · Hyvinge 33 km · Mäntsälä 49 km · Nurmijärvi 50 km · Hollola 50 km · Valkeakoski 51 km · Forssa 54 km

Finland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 85% of US
price level, 2025
GDP per capita
$56,149
2025
Happiness
7.8 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1
per 100k, 2023
Road deaths
3.9
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 603
Religion
Lutheran 67%none 31%other 2%Greek Orthodox 1%

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 Janakkala (60.9°, 24.6°, elevation 118 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).