Climate-Zone.com

HomeCitiesPuerto RicoIsabelaTools › Climate trends

Has the climate in Isabela changed?

Isabela has warmed about 2.9°F since 1971.

About 0.5°F per decade, measured from Isabela'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? Isabela's climate has warmed faster than most other cities in Puerto Rico.

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
about the same
1970s
0 / yr
Recent
0 / yr
Winters about as cold as before
Average temperature
+1.8°F
1970s
77.0°F
Recent
78.8°F
A steady upward drift
Hot days above 90°F
39 fewer days
1970s
120 / yr
Recent
81 / yr
Slightly fewer hot days
Rainy days
57 more days
1970s
117 / yr
Recent
174 / yr
Wetter on average

Isabela's temperature, year by year

Average temperature for each year from 1971 to 2025.

74°76°78°80°82°1971: 75.8°F1972: 77.1°F1973: 77.8°F1974: 76.5°F1975: 76.0°F1976: 75.7°F1977: 76.1°F1978: 75.0°F1979: 75.3°F1980: 78.5°F1981: 77.4°F1982: 78.4°F1983: 78.3°F1984: 77.2°F1985: 77.4°F1986: 77.1°F1987: 77.9°F1988: 77.8°F1989: 77.8°F1990: 77.2°F1991: 77.7°F1992: 78.0°F1993: 78.5°F1994: 77.6°F1995: 78.2°F1996: 76.9°F1997: 75.2°F1998: 75.6°F1999: 76.8°F2000: 77.4°F2001: 78.2°F2002: 79.2°F2003: 78.5°F2004: 78.3°F2005: 80.2°F2006: 77.5°F2007: 80.1°F2008: 78.1°F2009: 78.4°F2010: 79.0°F2011: 78.3°F2012: 78.4°F2013: 78.2°F2014: 78.6°F2015: 79.2°F2016: 79.4°F2017: 78.6°F2018: 78.2°F2019: 78.8°F2020: 79.5°F2021: 78.9°F2022: 78.6°F2023: 79.5°F2024: 79.9°F2025: 79.2°Flong-term trend1971198019902000201020202025
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 31 fewer 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.

0.0°+0.5°+1.0°+1.5°+2.0°January: +0.7°F+0.7JFebruary: +0.8°F+0.8FMarch: +1.0°F+1.0MApril: +1.1°F+1.1AMay: +1.1°F+1.1MJune: +1.3°F+1.3JJuly: +1.4°F+1.4JAugust: +1.6°F+1.6ASeptember: +1.6°F+1.6SOctober: +1.5°F+1.5ONovember: +1.3°F+1.3NDecember: +1.3°F+1.3D

August has warmed the most — about 1.6°F. The warming runs across the whole year, not just one season.

Methodology & sources

Temperature — 1991–2020 normals computed from 29 years of daily observations at Coloso, a weather station, about 19 km from the city centre. The underlying daily records come from NOAA's global station network.

How we build these numbers →