Ian Simpson
@iansimpson27.bsky.social
Post-doc in Antarctic weather extremes, FRMetS, long-standing weather enthusiast, chess player, Doom/Quake mapper, also interested in film and classical music and animation.
On this day 30 years ago, I woke up to a covering of snow in South Tyneside. It snowed for much of the morning, and in the afternoon it warmed up a bit near the coast with sleet and hail showers with thunder, but inland the showers stayed as snow, with thundersnow at Newcastle.
November 17, 2025 at 6:27 PM
On this day 30 years ago, I woke up to a covering of snow in South Tyneside. It snowed for much of the morning, and in the afternoon it warmed up a bit near the coast with sleet and hail showers with thunder, but inland the showers stayed as snow, with thundersnow at Newcastle.
Reposted by Ian Simpson
The disappearance of thicker #Arctic sea ice by decade in November...
More info on this data: climatedataguide.ucar.edu/climate-data...
More info on this data: climatedataguide.ucar.edu/climate-data...
November 14, 2025 at 12:14 PM
The disappearance of thicker #Arctic sea ice by decade in November...
More info on this data: climatedataguide.ucar.edu/climate-data...
More info on this data: climatedataguide.ucar.edu/climate-data...
Reposted by Ian Simpson
Consequences of the cold air outbreak. First snow of the winter now in Lahti, Finland 🌨️
November 14, 2025 at 4:45 PM
Consequences of the cold air outbreak. First snow of the winter now in Lahti, Finland 🌨️
Reposted by Ian Simpson
❌ "Sea Ice Today services reduced"
❌ "Ice Sheets Today services reduced"
"If you rely on these services, we would like to hear from you." via @nsidc.bsky.social (nsidc.org/sea-ice-toda... and nsidc.org/ice-sheets-t...)
❌ "Ice Sheets Today services reduced"
"If you rely on these services, we would like to hear from you." via @nsidc.bsky.social (nsidc.org/sea-ice-toda... and nsidc.org/ice-sheets-t...)
October 21, 2025 at 7:27 PM
❌ "Sea Ice Today services reduced"
❌ "Ice Sheets Today services reduced"
"If you rely on these services, we would like to hear from you." via @nsidc.bsky.social (nsidc.org/sea-ice-toda... and nsidc.org/ice-sheets-t...)
❌ "Ice Sheets Today services reduced"
"If you rely on these services, we would like to hear from you." via @nsidc.bsky.social (nsidc.org/sea-ice-toda... and nsidc.org/ice-sheets-t...)
Reposted by Ian Simpson
The @metoffice.gov.uk use weather station observations to reconstruct changes in UK average temperature since 1884.
@copernicusecmwf.bsky.social produce the ERA5 reanalysis which reconstructs global weather every hour back to 1950 using a weather forecast model.
Their estimates agree. Just sayin'.
@copernicusecmwf.bsky.social produce the ERA5 reanalysis which reconstructs global weather every hour back to 1950 using a weather forecast model.
Their estimates agree. Just sayin'.
October 6, 2025 at 9:03 AM
The @metoffice.gov.uk use weather station observations to reconstruct changes in UK average temperature since 1884.
@copernicusecmwf.bsky.social produce the ERA5 reanalysis which reconstructs global weather every hour back to 1950 using a weather forecast model.
Their estimates agree. Just sayin'.
@copernicusecmwf.bsky.social produce the ERA5 reanalysis which reconstructs global weather every hour back to 1950 using a weather forecast model.
Their estimates agree. Just sayin'.
Reposted by Ian Simpson
Happy October! 🍂 Like other times of year, our planet is heating up this month… but some regions warm faster than others. Arctic amplification especially ramps up in October.
Maps show the changes in October temperature over the last 4 decades. Data used from @copernicusecmwf.bsky.social ERA5.
Maps show the changes in October temperature over the last 4 decades. Data used from @copernicusecmwf.bsky.social ERA5.
October 5, 2025 at 12:52 PM
Happy October! 🍂 Like other times of year, our planet is heating up this month… but some regions warm faster than others. Arctic amplification especially ramps up in October.
Maps show the changes in October temperature over the last 4 decades. Data used from @copernicusecmwf.bsky.social ERA5.
Maps show the changes in October temperature over the last 4 decades. Data used from @copernicusecmwf.bsky.social ERA5.
I see that some of Bluesky's algorithms are going the same way as Big Tech's algorithms. I searched for posts on Storm Amy, and the default setting was "Top", and the algorithm promoted posts from between 6 and 24 hours ago, and buried a lot of relevant content from within the last two hours.
October 3, 2025 at 10:57 PM
I see that some of Bluesky's algorithms are going the same way as Big Tech's algorithms. I searched for posts on Storm Amy, and the default setting was "Top", and the algorithm promoted posts from between 6 and 24 hours ago, and buried a lot of relevant content from within the last two hours.
The wind has got up considerably here in Lincoln in the past hour. 50mph (81km/h) gusts reported at nearby RAF Waddington from #StormAmy according to www.weatherobs.com
Weatherobs
Global weather observations (METAR, SYNOP, BUOY, SHIP, TAF, CWOP) decoded to enable display of latest temperatures, weather, snow depths, precipitation, wind and wave conditions and more
www.weatherobs.com
October 3, 2025 at 7:31 PM
The wind has got up considerably here in Lincoln in the past hour. 50mph (81km/h) gusts reported at nearby RAF Waddington from #StormAmy according to www.weatherobs.com
Reposted by Ian Simpson
September 2025 was the third warmest September on record at 1.47C above preindustrial levels in ERA5, behind only the prior two years (2023 and 2024).
With 9 months of the year now in, I estimate 2025 will approximately tie with 2023 for the second warmest year on record at ~1.48C.
With 9 months of the year now in, I estimate 2025 will approximately tie with 2023 for the second warmest year on record at ~1.48C.
October 3, 2025 at 5:34 PM
September 2025 was the third warmest September on record at 1.47C above preindustrial levels in ERA5, behind only the prior two years (2023 and 2024).
With 9 months of the year now in, I estimate 2025 will approximately tie with 2023 for the second warmest year on record at ~1.48C.
With 9 months of the year now in, I estimate 2025 will approximately tie with 2023 for the second warmest year on record at ~1.48C.
Reposted by Ian Simpson
The Rainfall Observers
Over the past three centuries, thousands of people across the British & Irish Isles have recorded rainfall, often every day for decades. Here we recognise some of the individuals who made particularly important contributions.
rmets.onlinelibrary.wiley.com/doi/10.1002/...
Over the past three centuries, thousands of people across the British & Irish Isles have recorded rainfall, often every day for decades. Here we recognise some of the individuals who made particularly important contributions.
rmets.onlinelibrary.wiley.com/doi/10.1002/...
The rainfall observers
Over the past three centuries, thousands of people across the British and Irish Isles have regularly recorded rainfall, often every day for decades. Their efforts allow us to reconstruct long-term tr...
rmets.onlinelibrary.wiley.com
October 1, 2025 at 3:21 PM
The Rainfall Observers
Over the past three centuries, thousands of people across the British & Irish Isles have recorded rainfall, often every day for decades. Here we recognise some of the individuals who made particularly important contributions.
rmets.onlinelibrary.wiley.com/doi/10.1002/...
Over the past three centuries, thousands of people across the British & Irish Isles have recorded rainfall, often every day for decades. Here we recognise some of the individuals who made particularly important contributions.
rmets.onlinelibrary.wiley.com/doi/10.1002/...
According to the ERA5 based Climate Reanalyzer series, after hovering at 3rd-5th warmest in the summer, global temperatures have returned being clearly in the top 3 in September but behind 2023. I expect Copernicus's upcoming bulletin to have 2025 close to 2024. climatereanalyzer.org/clim/t2_dail...
Climate Reanalyzer
Climate and weather data visualizations
climatereanalyzer.org
October 1, 2025 at 3:32 PM
According to the ERA5 based Climate Reanalyzer series, after hovering at 3rd-5th warmest in the summer, global temperatures have returned being clearly in the top 3 in September but behind 2023. I expect Copernicus's upcoming bulletin to have 2025 close to 2024. climatereanalyzer.org/clim/t2_dail...
Reposted by Ian Simpson
Another likely casualty of the UK Online Safety Act - Imgur has blocked the UK.
That’s going to be a lot of broken images across the web for UK viewers on many sites.
That’s going to be a lot of broken images across the web for UK viewers on many sites.
September 29, 2025 at 10:48 PM
Another likely casualty of the UK Online Safety Act - Imgur has blocked the UK.
That’s going to be a lot of broken images across the web for UK viewers on many sites.
That’s going to be a lot of broken images across the web for UK viewers on many sites.
Reposted by Ian Simpson
In a UN speech today, President Trump said that "all of these [climate] predictions were wrong".
Back in 2019 I led a research effort to digitize old climate model projections and assess how well they did. Turns out they got future warming pretty spot on!
Back in 2019 I led a research effort to digitize old climate model projections and assess how well they did. Turns out they got future warming pretty spot on!
September 23, 2025 at 5:01 PM
In a UN speech today, President Trump said that "all of these [climate] predictions were wrong".
Back in 2019 I led a research effort to digitize old climate model projections and assess how well they did. Turns out they got future warming pretty spot on!
Back in 2019 I led a research effort to digitize old climate model projections and assess how well they did. Turns out they got future warming pretty spot on!
Reposted by Ian Simpson
Can’t read my own research publications (paywall). Can’t read the science news articles I’m interviewed for and quoted in (paywall). 🥹
September 20, 2025 at 12:28 PM
Can’t read my own research publications (paywall). Can’t read the science news articles I’m interviewed for and quoted in (paywall). 🥹
Reposted by Ian Simpson
After falling for much of the year (following the record warmth of 2023 and 2024), global temperatures have started to tick back up over the past 6 weeks. We are currently on track for the third warmest September on record.
September 16, 2025 at 2:35 AM
After falling for much of the year (following the record warmth of 2023 and 2024), global temperatures have started to tick back up over the past 6 weeks. We are currently on track for the third warmest September on record.
Reposted by Ian Simpson
A little bit of good news for you. And a reminder that we *can* solve big, global problems--when we want to. 🧪
(by @meghanbartels.bsky.social)
(by @meghanbartels.bsky.social)
The Ozone Hole Is Steadily Shrinking because of Global Efforts
After nearly 40 years of global efforts, the ozone hole over Antarctica is continuing to heal
www.scientificamerican.com
September 16, 2025 at 7:59 PM
A little bit of good news for you. And a reminder that we *can* solve big, global problems--when we want to. 🧪
(by @meghanbartels.bsky.social)
(by @meghanbartels.bsky.social)
Reposted by Ian Simpson
Today's (10th September) maximum temperatures and anomalies (compared to '91-'20 average) from SYNOP observations.
#Weybourne was the warmest location with a max #temperature of 22.4C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-09-10
#Weybourne was the warmest location with a max #temperature of 22.4C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-09-10
September 10, 2025 at 7:10 PM
Today's (10th September) maximum temperatures and anomalies (compared to '91-'20 average) from SYNOP observations.
#Weybourne was the warmest location with a max #temperature of 22.4C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-09-10
#Weybourne was the warmest location with a max #temperature of 22.4C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-09-10
Reposted by Ian Simpson
Also an interesting fact... if we took out the extraordinary heatwave that everybody remembers (and rightly so) from summer 1976 of 15 consecutive days of 90F in England (23 June to 7 July), the season has a CET of 16.8C.
Those 15 days gave a difference of nearly a whole degree!
Those 15 days gave a difference of nearly a whole degree!
August 31, 2025 at 10:41 AM
Also an interesting fact... if we took out the extraordinary heatwave that everybody remembers (and rightly so) from summer 1976 of 15 consecutive days of 90F in England (23 June to 7 July), the season has a CET of 16.8C.
Those 15 days gave a difference of nearly a whole degree!
Those 15 days gave a difference of nearly a whole degree!
Reposted by Ian Simpson
Met Office stats confirm summer 2025 is officially the warmest summer on record for the UK.
The UK’s mean temp of 16.10°C surpasses the previous record of 15.76°C and pushes the summer of 1976 out of the top 5 warmest summers.
www.metoffice.gov.uk/about-us/new...
The UK’s mean temp of 16.10°C surpasses the previous record of 15.76°C and pushes the summer of 1976 out of the top 5 warmest summers.
www.metoffice.gov.uk/about-us/new...
Summer 2025 is the warmest on record for the UK
Provisional Met Office statistics confirm that summer 2025 is officially the warmest summer on record for the UK.
www.metoffice.gov.uk
September 1, 2025 at 3:36 PM
Met Office stats confirm summer 2025 is officially the warmest summer on record for the UK.
The UK’s mean temp of 16.10°C surpasses the previous record of 15.76°C and pushes the summer of 1976 out of the top 5 warmest summers.
www.metoffice.gov.uk/about-us/new...
The UK’s mean temp of 16.10°C surpasses the previous record of 15.76°C and pushes the summer of 1976 out of the top 5 warmest summers.
www.metoffice.gov.uk/about-us/new...
For the Central England Temperature (CET), summer 2025 was "only" tied with 1976 for the hottest on record. But for the UK as a whole it was the hottest summer on record, and it wasn't close (0.3-0.4C warmer than the summers of 1976, 2003, 2006, 2018 & 2022). It also follows a record warm spring...
New analysis from @metoffice.gov.uk showing that the record-breaking hot UK summer of 2025 has been made much more likely by human-induced climate change and such a hot summer would be expected about once every 5 years in current climate. www.metoffice.gov.uk/about-us/new...
Summer 2025 is the warmest on record for the UK
Provisional Met Office statistics confirm that summer 2025 is officially the warmest summer on record for the UK.
www.metoffice.gov.uk
September 1, 2025 at 9:15 PM
For the Central England Temperature (CET), summer 2025 was "only" tied with 1976 for the hottest on record. But for the UK as a whole it was the hottest summer on record, and it wasn't close (0.3-0.4C warmer than the summers of 1976, 2003, 2006, 2018 & 2022). It also follows a record warm spring...
Some spectacular cumulonimbus clouds and an equally spectacular sunset sprouted up almost out of nowhere this evening in Lincoln, not long after I had given up on thundery potential for the day. These cells all turned into thunderstorms as they moved away north-eastwards. #lincoln #thunderstorms
August 27, 2025 at 10:06 PM
Some spectacular cumulonimbus clouds and an equally spectacular sunset sprouted up almost out of nowhere this evening in Lincoln, not long after I had given up on thundery potential for the day. These cells all turned into thunderstorms as they moved away north-eastwards. #lincoln #thunderstorms
I do a lot of coding in the Python programming language, which was originally named after Monty Python. Error messages are frequently annoying, but I reckon the following error messages would be fitting in some ways.
July 19, 2025 at 5:27 PM
I do a lot of coding in the Python programming language, which was originally named after Monty Python. Error messages are frequently annoying, but I reckon the following error messages would be fitting in some ways.
Reposted by Ian Simpson
3 years ago today, a historic weather day in the UK.
- Previous daily CET record was beaten by 2.8C
- 7 stations achieved 40C
- 46 stations bet the previous 38.7C record
- Previous high min record was beaten by 2.9C
- 60 stations had tropical night conditions
- Previous daily CET record was beaten by 2.8C
- 7 stations achieved 40C
- 46 stations bet the previous 38.7C record
- Previous high min record was beaten by 2.9C
- 60 stations had tropical night conditions
July 19, 2025 at 10:23 AM
3 years ago today, a historic weather day in the UK.
- Previous daily CET record was beaten by 2.8C
- 7 stations achieved 40C
- 46 stations bet the previous 38.7C record
- Previous high min record was beaten by 2.9C
- 60 stations had tropical night conditions
- Previous daily CET record was beaten by 2.8C
- 7 stations achieved 40C
- 46 stations bet the previous 38.7C record
- Previous high min record was beaten by 2.9C
- 60 stations had tropical night conditions
Reposted by Ian Simpson
A very warm July as of right now across the UK. Would be the 5th warmest on record since 1884 if the current average were to hold.
A changeable outlook in store but not much in the way of cool or hot weather so not likely to change considerably?
A changeable outlook in store but not much in the way of cool or hot weather so not likely to change considerably?
July 18, 2025 at 1:00 PM
A very warm July as of right now across the UK. Would be the 5th warmest on record since 1884 if the current average were to hold.
A changeable outlook in store but not much in the way of cool or hot weather so not likely to change considerably?
A changeable outlook in store but not much in the way of cool or hot weather so not likely to change considerably?
Reposted by Ian Simpson
Today's (18th July) maximum temperatures and anomalies (compared to '91-'20 average) from the 03xxx SYNOP sites.
#Northolt was the warmest location with a max #temperature of 31.0C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-07-18
#Northolt was the warmest location with a max #temperature of 31.0C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-07-18
July 18, 2025 at 7:10 PM
Today's (18th July) maximum temperatures and anomalies (compared to '91-'20 average) from the 03xxx SYNOP sites.
#Northolt was the warmest location with a max #temperature of 31.0C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-07-18
#Northolt was the warmest location with a max #temperature of 31.0C.
https://www.roostweather.com/ukobs/maxtemp_map.php?date=2025-07-18