Dr. Amy H Butler

February 2026 Colorado Monthly Climate Summary statewide departure from 1901-2000 avg: +9.2°F statewide departure from 1991-2020 avg: +7.6°F statewide rank: 1st warmest/132nd coldest Warmest February on record statewide Snowpack remains lowest in over 40 years Several locations, including Denver, Fort Collins, Akron, and Colorado Springs shatter records for most 60°F+ days Multiple grass fires, including ones near Boulder, Thornton, Matheson, and Wiggins Maximum daily precipitation (1.8" at Spud Mountain) Minimum daily temperature (-27°F in Taylor Park) Maximum daily temperature (85°F in Pueblo and Campo) Maximum daily snowfall 12.5" near Bayfield) February 2026 Temperature Rank (from NCEI nclimgrid) Statewide Temperature and Precipitation Ranks for February 2026 (based on 1895-2026 data) 1st warmest (record warmest) 37th driest (below average)

Unfortunately, not much good news to share in our February state climate summary. According to NOAA data, it was the warmest February in 132 years of records. Mountain snowpack remains at the lowest level in over 40 years. Several locations set new monthly high temperature records for February. 1/4

Dec-Feb was the 2nd warmest winter for the Contiguous U.S. according to ERA5 Reanalysis. 31% of the Contiguous U.S. had their warmest winter on record (since 1940), 53% were much above average, and only 1% was much below average (both compared to the 1991-2020 baseline).

Happy SSW Day ozonewatch.gsfc.nasa.gov/meteorology/...

Fort Collins number of days with TMAX >= 60°F, December through February. "Fort Collins has recorded 38 60°F days this winter. Previous high was 22 (1980-81). The remaining days in the month are all forecast to be 60 or above (five more).

@rschumacher.cloud on a state call this morning, talking about the crazy warmth we've been experiencing. The number of days Fort Collins has passed 60°F this winter, far surpasses any other winter!

NASA greenlights two earth science missions, to researchers’ relief Orbiting satellites will monitor changes in the stratosphere and on the planet’s surface

Geoscientists will soon have two powerful new eyes on Earth, offering unprecedented views of the changes occurring within the planet’s upper atmosphere and on its surface. https://scim.ag/3Mg0Xpa

This is now Denver's lowest season-to-date snow in 115 years.

#COwx

Fact check: Climate change is not making extreme cold more common Sometimes it just gets cold

Is climate change responsible for increasingly frequent or severe cold events?

The evidence suggests it is not.

Instead, the impact of climate change is warmer winters and less severe cold events.

@hausfath.bsky.social has a great post on The Climate Brink talking about this.

There have been some arguments that global warming leads to more cold extremes. However, that arguments mostly lives on because it is pushed by a few high-profile Big Accounts™. I don't think the literature supports it - neither in data, models, nor observations

3/

A time series of the January–February frequency (in days) of the AKR regime from 1979 to 2025 using ERA5 data, based on the year-round classification of Lee et al. 2023 (J. Climate) updated through 2025.

The extreme cold across eastern N America is due to the Alaskan Ridge regime, which on average brings the coldest winter weather to this region.

Is this happening more often?

No. During the modern warming era, there has been no observed trend in the occurrence of this regime at this time of year.

Jet stream response to future Arctic sea ice loss not underestimated by climate models npj Climate and Atmospheric Science - Jet stream response to future Arctic sea ice loss not underestimated by climate models

Proud to share our new paper in npj Clim. Atmos. Sci. (@SpringerNature)!

Our findings:
1️⃣ reduce uncertainty in mid-latitude climate projections
2️⃣ increase confidence that #ClimateModels correctly predict a future poleward shift of the #JetStream

Read the paper here 👉 rdcu.be/eS73b

#ClimateScience

The polar vortex is about to bring a wild weather pattern change | CNN Over the next 10 days, scientists say, changes in the stratosphere will upend weather patterns and set the stage for a cold, snowy December across parts of the Northern Hemisphere.

An unusually early sudden stratospheric warming event is likely to send the polar vortex on the move. Questions exist re: how this will affect US weather, but odds for colder, snowier weather are ticking up esp. in Central/Eastern US www.cnn.com/2025/11/19/w...

ECMWF 10 hPa 60°N zonal-mean zonal wind forecast from 13 Nov 2025 showing winds reversing to easterly, indicating a major SSW

The ensemble mean of today's IFS subseasonal forecast now predicts the earliest major sudden stratospheric warming in reliable records, beating 28 November 1968.

Will this verify? 👀

charts.ecmwf.int/products/ext...

It was well forecast for ~10 days, and the spv stratospheric polar vortex has now doubled in strength this past week

EC analysis showing W winds 10hpa 60N increasing from around 35mph to around 70mph

Models have also been forecasting a weakening going forward now..one to watch

Interesting to see so many ECMWF ensemble members producing a major sudden stratospheric warming event, where the 60N zonal wind at 10 hPa reverses, in late Nov or 1st half Dec.

In records back to 1959 I'm aware of only 3 major SSWs within 1st half Dec & none in November.

Screenshot that says "Sea Ice Today" and "Ice Sheets Today" Services Reduced. More information is stated: "Beginning October 15, 2025, NSIDC’s Sea Ice Today and Ice Sheets Today services will be reduced because of non-renewed funding. This means no new monthly and mid-month analysis posts for Sea Ice Today or regular posts for Ice Sheets Today, limited comparison tools, and reduced user support."

UGH! When will it end. 😭

"Effective October 15, 2025, due to non-renewed funding, NSIDC has suspended or reduced several Sea Ice Today tools and services."

nsidc.org/data/user-re...

QBOi‐SNAP‐QUOCA workshop: improved simulations of the stratosphere for better predictions of weather, climate and extreme events Click on the article title to read more.

QBOi-SNAP-QUOCA workshop: improved simulations of the stratosphere for better predictions of weather, climate and extreme events

Meeting report from the @wcrpclimate.bsky.social APARC workshop in Cambridge earlier this year

Free to view in @rmets.org Weather: doi.org/10.1002/wea....

In First Six Months, Cost of Weather Catastrophes Escalated at a Record Pace

www.nytimes.com/2025/10/22/c...

😂 no but I like the analogy!

Well I like the name! 😁

Great explainer by Martin Jucker @drjucker.bsky.social on the emerging Sudden Stratospheric Warming event over Antarctica, noting it is just one climate driver at play and does *not* lock in another 2019-like spring/summer.
(Thanks also to Martin for citing our 2019 SSW article with Harry and EunPa)

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!

Global map showing surface air temperature anomalies for the June to August 2025. Most all areas are warmer than average, except for parts of the southern Ocean and Antarctica. Anomalies are relative to 1951-1980 from NASA/GISS GISTEMPv4 data.

This map shows temperature departures averaged over the last 3 months. What's it like in your area?

🟥 warmer than average
🟦 colder than average

Data from data.giss.nasa.gov/gistemp/

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

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)

The Rise Of Climate.us A new nonprofit effort seeks to preserve and expand the functionality of a former popular government climate website. Can they succeed?

Many vital federal climate websites and data are increasingly difficult to access. A new nonproft organization called @climate.us seeks to fill the gap. My Labor Day thoughts in Forbes on their emergence.
www.forbes.com/sites/marsha...

Stratospheric Impacts on Weather Regimes Following the 2018 and 2019 Sudden Stratospheric Warmings Using a stratospheric nudging protocol with operational subseasonal systems, we assess weather impacts from sudden stratospheric warmings (SSWs) SSWs consistently shift the atmospheric state towa...

Stratospheric Impacts on Weather Regimes Following the 2018 and 2019 Sudden Stratospheric Warmings

New paper from @robertwlee.bsky.social, Andrew Charlton-Perez @unirdg-met.bsky.social and me, published today in @agu.org GRL

doi.org/10.1029/2025...

Also, NOAA Labs and Cooperative Institutes develop the warning software used by the TWCs (as well as NWS).

gsl.noaa.gov/research/pro...

It is an extraordinary loss of intellectual expertise that the American people invested millions in developing

Every scientist who earns a graduate degree in the US is the product of an investment by the public

This is like setting money on fire

Navy Set to Unplug Critical Hurricane Satellites this Week Abrupt termination of satellite data by U.S. Department of Defense sends forecasters scrambling for a fix on the brink of the busiest stretch of the hurricane season

If you think I've forgotten about the hurricane satellites, think again. The Navy is permanently unplugging them this week, on the brink of the busiest stretch of the season. There's so much more to this story, and I have the latest scoop. ⬇️

A map showing temperatures across Turkey, Saudi Arabia and northeast Africa on Friday 25th July 2025. Silopi, Şırnak, Turkey is marked on the map and a temperature of 50.5 Celsius is also marked. This is a new temperature record for Turkey.

Turkey recorded its highest temperature on record on Friday with 50.5°C recorded in Silopi ⚠️📈

This exceeds the previous record of 49.5°C recorded on 15th August 2023 🌡️

This extreme heat is bringing serious health impacts and giving a very high risk of wildfires 🔥