The Reliance School

1,900 Words / 8 min. Read

1.5 °C has long been considered an “upper limit” for climate change, beyond which the consequences become far more severe.^1,2 This was codified with the signing of the 2015 Paris Agreement, in which nearly 200 nations pledged to dramatically reduce their emissions in pursuit of that goal.³

It should come as no surprise that the world is nowhere close to meeting those commitments,⁴ and in 2018, IPCC projections showed we were on track to exceed 1.5 °C sometime between 2030 and 2052.⁵ But in early 2025, multiple communications briefs were published indicating that we may already be living in a world that’s 1.5 °C warmer.^6,7

In the previous post we took a look at that research, as well as the global consequences of crossing this threshold so much sooner than expected. In this post we’ve created a series of maps showing the effects of that warming on America, specifically in terms of temperature and rainfall.

Notes & Considerations

As we’re writing for an American audience, it’s important to note that 1.5 °C is the equivalent of 2.7 °F of warming. Since we’re not accustomed to using Celsius, it’s easy to subconsciously downplay the severity of this change. Here's a list of temperature conversions that show how warming in Celsius translates to degrees Fahrenheit:

• 1.5 °C = 2.7 °F
• 2 °C = 3.6 °F
• 3 °C = 5.4 °F
• 4 °C = 7.2 °F

You might also assume that if the world is warming by 2.7 °F, you can just add that number to the average temperature of your area. But that change isn't evenly distributed; latitude, altitude, and local climate all have a significant effect on how much warming your region may experience.^8,9

More importantly, climate change increases both the frequency and severity of extreme weather, particularly heat waves.¹⁰ So while the average temperature of your state or city may rise “only” a few degrees, the temperature on its hottest days could be significantly warmer. For example, a recent analysis by Climate Central found that summer temperatures in many US counties have warmed by over 5 °F since 1970, with Reno, NV setting the record with a rise of over 11 °F.¹¹

To show how 1.5 °C/2.7 °F of warming will affect different regions of America, we’ve created a series of interactive maps using county-level temperature and rainfall projections from the 5th National Climate Assessment (or NCA5), which was released in 2023. This assessment has been rigorously peer-reviewed, and is some of the most recent and comprehensive data available on climate change in America.¹² We’ll be combining these projections with historical climate data from NOAA (when available) to show how our climate baseline has shifted over the past 30 years.

If you find these maps helpful, we’ve extended these projections through 2 °C (3.6 °F) and 3 °C (5.4 °F) of warming in our free collection of climate risk maps.

Average Temperature

With all this in mind, let’s start by taking a look at changes in average temperature. This map shows degrees of warming in Fahrenheit:

As you can see, southern states are projected to experience between 1.3 °F and 2 °F of warming, while northern states are projected to warm by up to 2.6 °F. This difference is due in part to loss of ice and snow cover, as well as an increased transfer of heat from the tropics to the poles.^13,14

There are some exceptions to that trend; you can see that coastal areas experience less warming than inland areas, due to the moderating effect on temperature from the ocean.¹⁵ Areas of higher elevation (such as the Rocky Mountains) are also buffered from higher warming.

This map might imply that southern states are better-placed to weather the impacts of climate change, but remember that this is a map of relative changes, not absolute temperatures. Let’s switch over to a map of average temperature in a world that’s 2.7 °F warmer:

Despite a higher rate of change in higher latitudes, the southern US is still far warmer on average, with a difference of nearly 40 °F between the warmest and coldest states. Here the effect of altitude is more apparent, with the Appalachian and Rocky mountains standing out in contrast to lower-lying areas. More arid regions in the western US will also experience lower average temperatures, mainly due to colder nights.¹⁶

Days Over 95 °F

Extreme heat may be the most important factor to consider here; it’s the number-one weather-related cause of death in America, killing more people than hurricanes, floods, and tornadoes combined.¹⁷ Extended exposure to temperatures over 90 °F can cause dehydration, heat exhaustion, and heat stroke, and can exacerbate chronic conditions like heart disease.¹⁸

This map shows the projected change in the number of days per year over 95 °F:

Unfortunately the biggest increases are concentrated in regions which already experience some of the highest temperatures in the nation. Texas, Louisiana, and Florida are among the hardest-hit, with some counties experiencing 3 to 4 more weeks of extreme temperatures as a result of warming. Once again, coastal and mountain regions are spared from the heat.

This map shows the total number of days per year over 95 °F:

West Texas, Arizona, and California’s Central Valley are facing some of the most extreme heat in the nation, with some counties set to experience over 150 days per year over 95 °F. If you live in one of these areas, we would highly recommend searching for a new place to call home.

Days Under 32 °F

Next, let's take a look at the loss of freezing days. While that might seem like a welcome change in colder regions, loss of winter weather can have serious economic consequences for places whose economies depend on winter recreation.¹⁹ It increases drought and water scarcity in areas dependent on snowpack,²⁰ disrupts freeze-thaw cycles for food crops,²¹ and increases the populations of disease-carrying insects like mosquitos and ticks.²²

As expected, the biggest losses are in the northernmost regions of the US, with some counties losing up to three weeks of freezing weather each year. Washington, Oregon, Idaho, Montana, and Michigan are among the worst-affected; if you've lived in these regions for a decade or more, this is something you’ve likely experienced firsthand.

Average Rainfall

Climate change is projected to increase rainfall in most of the world; warmer air holds more moisture, and warmer temperatures lead to increased evaporation over oceans, intensifying the water cycle.^23,24 This holds true for most of the US, with some exceptions:

Northern and eastern regions are projected to receive between 3% and 5% more rainfall on average, but some areas of the southern US will see a decrease. Texas, New Mexico, and Arizona are the most affected, with some counties projected to experience a loss of 2% to 3% in annual precipitation.

Despite these changes, total precipitation still follows a clear trend; states west of the 100th meridian receive between 40” and 70” of rainfall per year, while most counties in the western US receive less than 20” on average. One big exception is the west coast of Northern California, Oregon, and Washington (also known as “Cascadia”), where moist ocean air is forced upward by the mountains and condenses into precipitation.^25,26

Extreme Rainfall

How rainfall arrives can be just as important as the overall amount; heavy rainfall can saturate the soil and overwhelm its holding capacity, leading to runoff, erosion, and flooding.²⁷ Climate change is projected to increase extreme precipitation events in 85% of US counties.²⁸

There are a few pockets where extreme rainfall may decrease, but most of the country is projected to experience between 10% and 30% more extreme precipitation events as a result of warming. The Midwest and Southeast are facing the biggest increase overall, but these changes aren’t evenly distributed; we encourage you to zoom in on your region or county to see how you’ll be affected.

Our Shifting Baseline

Unlike projections for a world that’s 2 °C or 3 °C warmer, these maps are modeling the world we’re living in right now. In 2024 we experienced a full year above 1.5 °C,²⁹ with 2025 on track to follow course.³⁰ For younger generations, this may quickly become “the new normal.” A 2025 study in Nature Climate Change looked at how people respond psychologically to changes in temperature, and concluded that:

For much of the global population, climate change appears as a slow, gradual shift in daily weather. This leads many to perceive its impacts as minor and results in apathy (the ‘boiling frog’ effect).³¹

A Grist article continues:

The metaphor of the “boiling frog” is sometimes used to describe how people fail to react to gradual changes in the climate. The idea is that if you put a frog in boiling water, it’ll immediately jump out. But if you put it in room-temperature water and slowly turn up the heat, the frog won’t realize the danger and will be boiled alive.

Although real frogs are actually smart enough to hop out when water gets dangerously hot, the metaphor fits humans when it comes to climate change: People mentally adjust to temperature increases “disturbingly fast,” according to the study. Previous research has found that as the climate warms, people adjust their sense of what seems normal based on weather from the past two to eight years, a phenomenon known as “shifting baselines.”³²

In other words, each new generation sees the condition of their climate and ecosystem as the baseline,³³ when in reality we’re living in a world whose natural systems have been severely impacted and degraded for centuries.³⁴

It’s important to recognize that the current state of the world is anything but normal. We’re overshooting our planetary boundaries and destroying the life support systems upon which we depend,³⁵ tracking a course for a future where modern civilization may no longer be able to sustain itself.^36,37 Our climate is one symptom of many, which is why we continually advocate for a holistic approach to resilience, transforming both ourselves and the systems that got us to this place.

If you live in one of the most affected regions of these maps, we’ve written a 4-part series on finding a safer place to call home, where we’ve identified key factors to consider when searching for higher ground. And since climate change will affect us all (regardless of where we live), we’ve created a [crash course on personal resilience] with 5 principles and practices you can start working with right now.

We hope these resources help you work towards creating a more secure and sustainable future; while we may not be able to steer the ship, together we can build lifeboats to weather the storm.³⁸

Footnotes & References

1. The impacts of climate change at 1.5C, 2C and beyond (Carbon Brief)
2. ‘Every 0.1C’ of overshoot above 1.5C increases risk of crossing tipping points (Ayesha Tandon, Carbon Brief)
3. The Paris Agreement (United Nations Framework Convention on Climate Change)
4. Countries (Climate Action Tracker)
5. When might the world exceed 1.5C and 2C of global warming? (Zeke Hausfather, Carbon Brief)
6. A year above 1.5 °C signals that Earth is most probably within the 20-year period that will reach the Paris Agreement limit (Emanuele Bevacqua, Carl-Friedrich Schleussner, Jakob Zscheischler, Nature Climate Change)
7. Twelve months at 1.5 °C signals earlier than expected breach of Paris Agreement threshold (Alex Cannon, Nature Climate Change)
8. Which parts of the planet are warming the fastest, and why? (Lindsay Fendt, Adam Schlosser, MIT Climate Portal)
9. Climate Change: Regional Impacts (UCAR)
10. Climate Change and the Escalation of Global Extreme Heat (Climate Central)
11. 2025 Summer Package (Climate Central)
12. Information Quality (Fifth National Climate Assessment)
13. 'Global' warming varies greatly depending where you live (Zeke Hausfather, PreventionWeb)
14. Why does the Arctic warm faster than the rest of the planet? (Matthew Henry, Carbon Brief)
15. Why does land warm up faster than the oceans? (Michael Byrne, Carbon Brief)
16. Why do deserts get so cold at night? (Harry Baker, Live Science)
17. Extreme Heat Is Deadlier Than Hurricanes, Floods and Tornadoes Combined (Terri Adams-Fuller, Scientific American)
18. The dangers of extreme heat (Aaron Bernstein, Harvard School of Public Healh)
19. How Climate Change is Shaping Winter Recreation (Climate Central)
20. Climate Change Indicators: Snowpack (EPA)
21. Freeze-Thaw Cycles (Great Lakes Integrated Sciences and Assessments)
22. Climate Change and Vectorborne Diseases (Madeleine Thomson, Lawrence Stanberry, The New England Journal of Medicine)
23. Chapter 8: Water Cycle Changes (IPCC Sixth Assessment Report)
24. Climate change impact on flood and extreme precipitation increases with water availability (Hossein Tabari, Scientific Reports)
25. The Cascadia Bioregion (Cascadian Bioregion Department)
26. Why does Oregon get so much rainfall? (Eunice Sutton, NCESC)
27. Flood Basics (NOAA National Severe Storms Laboratory)
28. Extreme Precipitation in a Warming Climate (Climate Central)
29. Hottest May on record spurs call for climate action (Copernicus Climate Change Service)
30. Earth is heading for a second year above 1.5°C climate goal (Madeleine Cuff, NewScientist)
31. Binary climate data visuals amplify perceived impact of climate change (Grace Liu, Jake Snell, Thomas Griffiths, Rachit Dubey, Nature Human Behaviour)
32. Scientists just found a way to break through climate apathy (Kate Yoder, Grist)
33. Shifting baseline syndrome: causes, consequences, and implications (Masashi Soga, Kevin Gaston, Frontiers in Ecology and the Environment)
34. Anthropocene (Wikipedia)
35. Earth beyond six of nine planetary boundaries (Katherine Richardson, Will Steffen, Wolfgang Lucht, Jørgen Bendtsen, Sarah Cornell, Jonathan Donges, Markus Drüke, Ingo Fetzer, Govindasamy Bala, Werner von Blo, Georg Feulner, Stephanie Fiedler, Dieter Gerten, Tom Gleeson, Matthias Hofmann, Willem Huiskamp, Matti Kummu, Chinchu Mohan, David Nogués-Bravo , Stefan Petri, Miina Porkka, Stefan Rahmstorf, Sibyll Schaphoff, Kirsten Thonicke, Arne Tobian, Vili Virkki, Lan Wang-Erlandsson, Lisa Weber, Johan Rockström, Science Advances)
36. Climate Endgame: Exploring catastrophic climate change scenarios (Luke Kemp, Joanna Depledge, Kristie Ebi , Goodwin Gibbins, Timothy Kohler, Johan Rockström, Marten Scheffer, Hans Joachim Schellnhuber, Will Steffen, Timothy Lenton, PNAS)
37. Planetary Solvency – finding our balance with nature (Institute and Faculty of Actuaries)
38. Building Lifeboats – Building Community (Andrew Willner, The Center for Post Carbon Logistics)