About 0.2°F per decade, measured from Keene's official daily weather records, 1971–2025. Individual years still bounce around — some recent ones came in cool — but the long-term line has clearly risen.
Is that a lot? Keene's climate has warmed more slowly than most other cities in United States.
What has actually changed
Each card compares the 1970s (the first ten years of the
record) with recent years (the last ten) — the same span
the headline and the chart use.
Freezing nights
5 fewer nights
1970s
155 / yr
→
Recent
150 / yr
Milder winters — fewer frosts
Average temperature
+0.7°F
1970s
48.5°F
→
Recent
49.2°F
A steady upward drift
Hot days above 90°F
1 more day
1970s
11 / yr
→
Recent
12 / yr
More days of serious heat
Rainy days
9 more days
1970s
121 / yr
→
Recent
130 / yr
Wetter on average
Keene's temperature, year by year
Average temperature for each year from 1971 to 2025.
a warmer-than-average year a cooler-than-average year
Each bar is one year. Most recent years sit above the older ones.
Some recent years still came in cool — warming is a slope,
not a straight climb.
When in the year the change shows up
How much warmer each month is now than in the 1970s.
Useful if you garden or care about a particular season —
otherwise the headline above already has the answer.
March has cooled the most — about 1.3°F. The warming runs across the whole year, not just one season.
Methodology & sources
Temperature — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Amherst (NOAA GHCN station USC00190120), about 64 km from the city centre.