Mika Rantanen
@mikarantane.bsky.social
Researcher at the Finnish Meteorological Institute. Climate change, extreme weather and attribution of extreme events. PhD in meteorology from the University of Helsinki.
Pinned
Mika Rantanen
@mikarantane.bsky.social
· Apr 28
Summer 2024 in northern Fennoscandia was very likely the warmest in 2000 years - npj Climate and Atmospheric Science
npj Climate and Atmospheric Science - Summer 2024 in northern Fennoscandia was very likely the warmest in 2000 years
doi.org
Excited to share that our new paper
“Summer 2024 in northern Fennoscandia was very likely the warmest in 2000 years”
has been published in npj Climate and Atmospheric Science!
See the open-access paper from doi.org/10.1038/s416...
Short thread 👇
“Summer 2024 in northern Fennoscandia was very likely the warmest in 2000 years”
has been published in npj Climate and Atmospheric Science!
See the open-access paper from doi.org/10.1038/s416...
Short thread 👇
Helmikuun puoliväliin ehkä? Sen jälkeen ei ole takeita.
February 2, 2026 at 2:31 PM
Helmikuun puoliväliin ehkä? Sen jälkeen ei ole takeita.
Cold January! The wind rose from Helsinki Kaisaniemi shows that the most common wind direction so far this year has been from the northeast.
Wind has blown from that direction almost half (44%) of the time.
Wind has blown from that direction almost half (44%) of the time.
February 2, 2026 at 2:22 PM
Cold January! The wind rose from Helsinki Kaisaniemi shows that the most common wind direction so far this year has been from the northeast.
Wind has blown from that direction almost half (44%) of the time.
Wind has blown from that direction almost half (44%) of the time.
Juuri tippui alemmas, -63,7 cm, eli 2000-luvun alin lukema.
Kirjallisuuden mukaan Föglön havainnot vastaavat aika hyvin koko Itämeren vesimäärää, koska mareografi sijaitsee pääaltaan pohjoisreunalla.
Kirjallisuuden mukaan Föglön havainnot vastaavat aika hyvin koko Itämeren vesimäärää, koska mareografi sijaitsee pääaltaan pohjoisreunalla.
February 2, 2026 at 11:47 AM
Juuri tippui alemmas, -63,7 cm, eli 2000-luvun alin lukema.
Kirjallisuuden mukaan Föglön havainnot vastaavat aika hyvin koko Itämeren vesimäärää, koska mareografi sijaitsee pääaltaan pohjoisreunalla.
Kirjallisuuden mukaan Föglön havainnot vastaavat aika hyvin koko Itämeren vesimäärää, koska mareografi sijaitsee pääaltaan pohjoisreunalla.
January climate statistics are out. Remarkably in Lapland, January 2026 was the coldest month since January 1987!
www.ilmatieteenlaitos.fi/tiedote/1GU2...
www.ilmatieteenlaitos.fi/tiedote/1GU2...
February 2, 2026 at 9:21 AM
January climate statistics are out. Remarkably in Lapland, January 2026 was the coldest month since January 1987!
www.ilmatieteenlaitos.fi/tiedote/1GU2...
www.ilmatieteenlaitos.fi/tiedote/1GU2...
It's a result from the ongoing weather pattern. The high pressure and persistent northerly/northeasterly winds have pushed water away from the Baltic Sea.
February 2, 2026 at 7:42 AM
It's a result from the ongoing weather pattern. The high pressure and persistent northerly/northeasterly winds have pushed water away from the Baltic Sea.
The total water volume in the Baltic Sea continues to drop. The mean water level dropped to -62.0 cm at the Föglö tide gauge today morning.
This is now the 2nd lowest reading in the 21st century, surpassed only by the March 2013 cold wave (-63.4 cm).
en.ilmatieteenlaitos.fi/sea-level?se...
This is now the 2nd lowest reading in the 21st century, surpassed only by the March 2013 cold wave (-63.4 cm).
en.ilmatieteenlaitos.fi/sea-level?se...
February 2, 2026 at 7:20 AM
The total water volume in the Baltic Sea continues to drop. The mean water level dropped to -62.0 cm at the Föglö tide gauge today morning.
This is now the 2nd lowest reading in the 21st century, surpassed only by the March 2013 cold wave (-63.4 cm).
en.ilmatieteenlaitos.fi/sea-level?se...
This is now the 2nd lowest reading in the 21st century, surpassed only by the March 2013 cold wave (-63.4 cm).
en.ilmatieteenlaitos.fi/sea-level?se...
Reposted by Mika Rantanen
Helsinki saw its coldest January since 2016 with a mean temperature of -7.4°C.
February 1, 2026 at 1:20 PM
Helsinki saw its coldest January since 2016 with a mean temperature of -7.4°C.
The regions that have lost much ice show indeed the highest warning trend. In Finnish Lapland the trend is weaker.
In addition, the trend depends on the starting year of the trend. January has warmed too from the 1979.
Fig. from www.nature.com/articles/s43...
In addition, the trend depends on the starting year of the trend. January has warmed too from the 1979.
Fig. from www.nature.com/articles/s43...
February 1, 2026 at 6:58 AM
The regions that have lost much ice show indeed the highest warning trend. In Finnish Lapland the trend is weaker.
In addition, the trend depends on the starting year of the trend. January has warmed too from the 1979.
Fig. from www.nature.com/articles/s43...
In addition, the trend depends on the starting year of the trend. January has warmed too from the 1979.
Fig. from www.nature.com/articles/s43...
Interesting is also the seemingly lack of warming in January. The three warmest Januaries are 1925, 1934 and 2001.
Linear trend over 1901–2026 is -0.03°C/decade.
Centennial-scale lack of warming within the Arctic Circle must be rare? Could be a good topic for a small study.
Linear trend over 1901–2026 is -0.03°C/decade.
Centennial-scale lack of warming within the Arctic Circle must be rare? Could be a good topic for a small study.
January 31, 2026 at 11:35 AM
Interesting is also the seemingly lack of warming in January. The three warmest Januaries are 1925, 1934 and 2001.
Linear trend over 1901–2026 is -0.03°C/decade.
Centennial-scale lack of warming within the Arctic Circle must be rare? Could be a good topic for a small study.
Linear trend over 1901–2026 is -0.03°C/decade.
Centennial-scale lack of warming within the Arctic Circle must be rare? Could be a good topic for a small study.
January is soon in the books, and what an exceptionally cold month it has been in northern Fennoscandia!
The monthly mean temperature in Sodankylä Tähtelä will be -21.2 °C. This means coldest January since 1987 and 5th coldest overall.
The monthly mean temperature in Sodankylä Tähtelä will be -21.2 °C. This means coldest January since 1987 and 5th coldest overall.
January 31, 2026 at 11:35 AM
January is soon in the books, and what an exceptionally cold month it has been in northern Fennoscandia!
The monthly mean temperature in Sodankylä Tähtelä will be -21.2 °C. This means coldest January since 1987 and 5th coldest overall.
The monthly mean temperature in Sodankylä Tähtelä will be -21.2 °C. This means coldest January since 1987 and 5th coldest overall.
Reposted by Mika Rantanen
I've seen several Big Climate Accounts™ post about how the recent winter storm was made worse by climate change. It's a convenient narrative.
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
January 31, 2026 at 3:29 AM
I've seen several Big Climate Accounts™ post about how the recent winter storm was made worse by climate change. It's a convenient narrative.
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
s
But what is "worse"? Colder temperatures? More snow? More freezing rain? Is there any primary literature supporting the idea of worse snowstorms?
1/
Except not for cold extremes!
January 31, 2026 at 5:53 AM
Except not for cold extremes!
Kiitos! välillä mietin että lukeeko niitä kukaan.
Mutta joo, etelässä ei kyllä ollut kovin kylmää, ja muutenkin etelässä tuntuu kovimmat pakkaset vähentyneen selkeämmin kuin Lapissa.
Mutta joo, etelässä ei kyllä ollut kovin kylmää, ja muutenkin etelässä tuntuu kovimmat pakkaset vähentyneen selkeämmin kuin Lapissa.
January 30, 2026 at 1:52 PM
Kiitos! välillä mietin että lukeeko niitä kukaan.
Mutta joo, etelässä ei kyllä ollut kovin kylmää, ja muutenkin etelässä tuntuu kovimmat pakkaset vähentyneen selkeämmin kuin Lapissa.
Mutta joo, etelässä ei kyllä ollut kovin kylmää, ja muutenkin etelässä tuntuu kovimmat pakkaset vähentyneen selkeämmin kuin Lapissa.
Yritin etsiä jostain Laatokan jäätilannetta mutta en löytänyt! Meteorologit totesivat sisäisessä viestinnässä että "Laatokka on jo lähes kokonaan jäässä, samoin Perämerellä on laaja jääpeite."
January 30, 2026 at 10:21 AM
Yritin etsiä jostain Laatokan jäätilannetta mutta en löytänyt! Meteorologit totesivat sisäisessä viestinnässä että "Laatokka on jo lähes kokonaan jäässä, samoin Perämerellä on laaja jääpeite."
Extreme seasons recently in Finnish Lapland: both summer 2025 and winter 2026 featured the 3rd hottest and 3rd coldest two-week periods on record.
Data is based on FMI ClimGrid (available since 1961).
Data is based on FMI ClimGrid (available since 1961).
January 30, 2026 at 9:17 AM
Extreme seasons recently in Finnish Lapland: both summer 2025 and winter 2026 featured the 3rd hottest and 3rd coldest two-week periods on record.
Data is based on FMI ClimGrid (available since 1961).
Data is based on FMI ClimGrid (available since 1961).
The Bothnian Bay is completely frozen. The ongoing high-pressure dominated and cold weather type will continue to favour sea ice formation in the Baltic Sea.
www.ilmatieteenlaitos.fi/jaatilanne
www.ilmatieteenlaitos.fi/jaatilanne
January 29, 2026 at 1:11 PM
The Bothnian Bay is completely frozen. The ongoing high-pressure dominated and cold weather type will continue to favour sea ice formation in the Baltic Sea.
www.ilmatieteenlaitos.fi/jaatilanne
www.ilmatieteenlaitos.fi/jaatilanne
Lisää blogissa: suomenluonto.fi/tammikuun-20...
Tammikuun 2026 pakkasjakso Lapissa oli 2000-luvun kylmin
Alkuvuoden kahden viikon pituinen ajanjakso Lapin maakunnassa oli hyisin sitten vuoden 1987.
suomenluonto.fi
January 29, 2026 at 9:30 AM
Lisää blogissa: suomenluonto.fi/tammikuun-20...
Arktinen kiihdytyskaista vauhdittaa koko maapallon lämpenemistä – neljä tutkijaa kertoo, mistä on kyse
yle.fi/a/74-20202928
yle.fi/a/74-20202928
Arktinen kiihdytyskaista vauhdittaa koko maapallon lämpenemistä – neljä tutkijaa kertoo, mistä on kyse
Ilmasto lämpenee pohjoisella napa-alueella jopa neljä kertaa nopeammin kuin maapallolla keskimäärin. Lapissa nousu on jo 2,5 astetta. Ja vauhti vain kiihtyy.
yle.fi
January 28, 2026 at 5:08 PM
Arktinen kiihdytyskaista vauhdittaa koko maapallon lämpenemistä – neljä tutkijaa kertoo, mistä on kyse
yle.fi/a/74-20202928
yle.fi/a/74-20202928
Siinä taisi olla kuun puolivälissä lauhempi jakso jolloin kasvu tasaantui hetkeksi.
January 28, 2026 at 3:39 PM
Siinä taisi olla kuun puolivälissä lauhempi jakso jolloin kasvu tasaantui hetkeksi.
Perämeri jäätynee lähipäivinä kokonaan kiinni!
January 28, 2026 at 3:38 PM
Perämeri jäätynee lähipäivinä kokonaan kiinni!
Yeah, there is probably correlation between temperature and precipitation in January, meaning that cold Januaries are usually dry. But this year's January has been exceptionally dry in Kuopio region!
January 28, 2026 at 1:18 PM
Yeah, there is probably correlation between temperature and precipitation in January, meaning that cold Januaries are usually dry. But this year's January has been exceptionally dry in Kuopio region!
Reposted by Mika Rantanen
New discussion paper just dropped that’s taken shall we say a little work to get this far … essd.copernicus.org/preprints/es... please be kind. Not on an at all sensitive topic in the slightest.
How well can we quantify when 1.5 °C of global warming has been exceeded?
Abstract. Parties to the 2015 Paris Agreement agreed to limit the long-term increase in global average temperature to well below 2 °C and pursue efforts to keep temperatures below 1.5 °C relative to p...
essd.copernicus.org
January 28, 2026 at 8:48 AM
New discussion paper just dropped that’s taken shall we say a little work to get this far … essd.copernicus.org/preprints/es... please be kind. Not on an at all sensitive topic in the slightest.
Ehkä vähemmälle huomiolle on jäänyt se, että Lapissa alkuvuoden kahden viikon ajanjakso oli paikoin jopa ennätyksellisen kylmä.
Ylitornion Meltosjärvellä 14 vrk keskilämpötila oli -29,8 astetta (!), joka oli aseman mittaushistorian kylmin kaksiviikkoinen.
Ylitornion Meltosjärvellä 14 vrk keskilämpötila oli -29,8 astetta (!), joka oli aseman mittaushistorian kylmin kaksiviikkoinen.
January 27, 2026 at 11:59 AM
Ehkä vähemmälle huomiolle on jäänyt se, että Lapissa alkuvuoden kahden viikon ajanjakso oli paikoin jopa ennätyksellisen kylmä.
Ylitornion Meltosjärvellä 14 vrk keskilämpötila oli -29,8 astetta (!), joka oli aseman mittaushistorian kylmin kaksiviikkoinen.
Ylitornion Meltosjärvellä 14 vrk keskilämpötila oli -29,8 astetta (!), joka oli aseman mittaushistorian kylmin kaksiviikkoinen.
Here are snow depths and their departures from average at this time of the year. The lack of snow seems to be most anomalous in eastern Finland where you are missing about 20 cm of snow. Category is "unusual" which means about once per 10 years recurrence interval.
January 27, 2026 at 6:32 AM
Here are snow depths and their departures from average at this time of the year. The lack of snow seems to be most anomalous in eastern Finland where you are missing about 20 cm of snow. Category is "unusual" which means about once per 10 years recurrence interval.
Due to current weather pattern, the sea level in the Baltic Sea is about half a meter lower than normally.
At the Föglö tide gauge, that is located in the northern part of the main basin, the observed -53 cm is the lowest since 2018.
At the Föglö tide gauge, that is located in the northern part of the main basin, the observed -53 cm is the lowest since 2018.
January 26, 2026 at 5:36 PM
Due to current weather pattern, the sea level in the Baltic Sea is about half a meter lower than normally.
At the Föglö tide gauge, that is located in the northern part of the main basin, the observed -53 cm is the lowest since 2018.
At the Föglö tide gauge, that is located in the northern part of the main basin, the observed -53 cm is the lowest since 2018.