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Has the climate in Longmont changed?

Longmont has warmed about 2°F since 1974.

About 0.4°F per decade, measured from Longmont's official daily weather records, 1974–2025. Individual years still bounce around — some recent ones came in cool — but the long-term line has clearly risen.

Is that a lot? Longmont'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
7 fewer nights
1970s
165 / yr
Recent
158 / yr
Milder winters — fewer frosts
Average temperature
+1.2°F
1970s
50.1°F
Recent
51.2°F
A steady upward drift
Hot days above 90°F
17 more days
1970s
39 / yr
Recent
56 / yr
More days of serious heat
Rainy days
10 fewer days
1970s
76 / yr
Recent
66 / yr
Drier on average

Longmont's temperature, year by year

Average temperature for each year from 1974 to 2025.

46°48°50°52°54°1974: 49.5°F1975: 49.0°F1976: 50.1°F1977: 52.5°F1978: 49.0°F1979: 48.1°F1980: 50.0°F1981: 52.0°F1982: 49.5°F1983: 48.5°F1984: 49.0°F1985: 49.3°F1986: 52.2°F1987: 50.8°F1988: 50.6°F1989: 50.3°F1990: 50.8°F1991: 49.7°F1992: 50.4°F1993: 47.2°F1994: 50.5°F1995: 49.1°F1996: 49.4°F1997: 48.4°F1998: 50.5°F1999: 51.7°F2000: 51.2°F2001: 51.1°F2002: 49.8°F2003: 50.8°F2004: 51.2°F2005: 50.9°F2006: 51.0°F2007: 50.4°F2008: 50.1°F2009: 49.0°F2010: 51.0°F2011: 50.0°F2012: 53.2°F2013: 49.9°F2014: 50.1°F2015: 51.6°F2016: 51.8°F2017: 52.8°F2018: 51.6°F2019: 49.8°F2020: 51.5°F2021: 51.9°F2022: 50.5°F2023: 50.3°F2024: 53.0°F2025: 52.6°Flong-term trend1974198019902000201020202025
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.

In day-to-day terms, that long-term shift shows up as about 11 more days above 90°F compared with the 1970s.

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.

-1.5°-1.0°-0.5°0.0°+0.5°+1.0°+1.5°+2.0°January: +1.8°F+1.8JFebruary: -1.2°F-1.2FMarch: +0.7°F+0.7MApril: +0.2°F+0.2AMay: -0.3°F-0.3MJune: +0.9°F+0.9JJuly: +1.4°F+1.4JAugust: +1.4°F+1.4ASeptember: +1.1°F+1.1SOctober: -0.5°F-0.5ONovember: +1.9°F+1.9NDecember: +0.3°F+0.3D

November has warmed the most — about 1.9°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 Brighton 3 SE (NOAA GHCN station USC00050950), about 34 km from the city centre.

How we build these numbers →