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Has the climate in Portsmouth changed?
Portsmouth has warmed about 2.3°F since 2002.
About 0.9°F per decade, measured from Portsmouth's official daily weather records, 2002–2025. Individual years still bounce around — some recent ones came in cool — but the long-term line has clearly risen.
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.
Portsmouth's temperature, year by year
Average temperature for each year from 2002 to 2025.
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.
Methodology & sources
Temperature — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Durham 2 N (NOAA GHCN station USW00054794), about 17 km from the city centre.