The United States has been keeping a nationwide temperature record since 1895, and it tells a clear story: the contiguous U.S. is warmer now than at any point in that 130-year record, and almost every one of the warmest years has occurred recently. This guide walks through the long warming trend across the Lower 48, shows which states have heated up the most, and explains why some regions warmed faster than others.
How much has the U.S. warmed since 1895?
Averaged across the contiguous 48 states, annual temperatures have risen well over a degree Fahrenheit since the record began — and the warming has accelerated since the 1970s. The year-to-year line is jagged because weather is noisy, but the trend is unmistakable: the coldest years cluster in the early 1900s, the warmest in the last two decades. The exact figures update live in the chart and stat cards above.
Which states have warmed the most?
Warming has not been even. The map above shades each state by how much its recent temperatures exceed its early-1900s baseline. In general the Northeast and the Southwest have warmed fastest, while parts of the Southeast warmed least — a quirk sometimes called the "warming hole." The ranking below lists the states that have changed the most.
Why did some regions warm faster than others?
Several factors drive the regional differences: changes in cloud cover and rainfall, shifts in agriculture and irrigation, aerosol pollution that temporarily masked warming in some areas, and natural ocean cycles that influence regional climate. The Southeast's relatively slow warming is an active area of research, but it does not change the national picture — the country as a whole is clearly and steadily getting warmer.
Are recent years really the warmest on record?
Yes. When climate scientists rank the hottest years in the 1895–present U.S. record, the overwhelming majority fall in the 21st century. A single hot or cool year reflects weather; the fact that nearly all the record-warm years are recent reflects climate. That's the difference the long record makes — it lets you separate a noisy line from a clear trend.
Frequently asked questions
How much has the U.S. warmed since 1895?
The contiguous U.S. annual average has risen well over a degree Fahrenheit since 1895, with most of the warming concentrated since the 1970s. The live figure is shown above.
Which U.S. states have warmed the most?
The Northeast and Southwest have generally warmed fastest, while parts of the Southeast warmed least. The map and ranking above show each state's change.
What is the 'warming hole'?
It's the nickname for the southeastern U.S., where temperatures rose more slowly than the rest of the country during much of the 20th century — likely due to a mix of rainfall, land-use, and pollution effects.
Are recent years the hottest on record?
Yes — the large majority of the warmest years in the 1895-present U.S. record have occurred in the 21st century.
Where does this temperature data come from?
From NOAA's National Centers for Environmental Information (NCEI), which compiles the official U.S. climate record from thousands of weather stations.